use std::{fs, path::PathBuf};

use async_trait::async_trait;
use glob::glob;

use crate::{
  error::Result,
  model::{Config, LockFile, ProjectSide, ProjectType},
};

#[derive(Clone)]
pub struct RuleContext {
  pub lockfile:       LockFile,
  pub config:         Config,
  pub profile_config: Option<crate::export::ProfileConfig>,
  pub export_path:    PathBuf,
  pub base_path:      PathBuf,
  pub ui:             Option<indicatif::ProgressBar>,
}

pub trait Rule: Send + Sync {
  fn matches(&self, context: &RuleContext) -> bool;
  fn effects(&self) -> Vec<Box<dyn Effect>>;
}

#[async_trait]
pub trait Effect: Send + Sync {
  fn name(&self) -> &str;
  async fn execute(&self, context: &RuleContext) -> Result<()>;
}

// Rule: Copy project files
pub struct CopyProjectFilesRule;

impl Rule for CopyProjectFilesRule {
  fn matches(&self, _context: &RuleContext) -> bool {
    true
  }

  fn effects(&self) -> Vec<Box<dyn Effect>> {
    vec![Box::new(CopyProjectFilesEffect)]
  }
}

pub struct CopyProjectFilesEffect;

#[async_trait]
impl Effect for CopyProjectFilesEffect {
  fn name(&self) -> &'static str {
    "Downloading and copying project files"
  }

  async fn execute(&self, context: &RuleContext) -> Result<()> {
    use crate::model::ResolvedCredentials;

    // Resolve credentials (env -> keyring -> Pakker file -> Pakku file).
    let credentials = ResolvedCredentials::load()?;
    let curseforge_key =
      credentials.curseforge_api_key().map(ToOwned::to_owned);
    let modrinth_token = credentials.modrinth_token().map(ToOwned::to_owned);

    for project in &context.lockfile.projects {
      if !project.export {
        continue;
      }

      if let Some(file) = project.files.first() {
        // Get the target directory based on project type and paths config
        let type_dir = get_project_type_dir(&project.r#type, &context.config);

        // Handle subpath if specified
        let target_subdir = if let Some(subpath) = &project.subpath {
          PathBuf::from(&type_dir).join(subpath)
        } else {
          PathBuf::from(&type_dir)
        };

        let export_dir = context.export_path.join(&target_subdir);
        fs::create_dir_all(&export_dir)?;

        let source = context.base_path.join(&type_dir).join(&file.file_name);
        let dest = export_dir.join(&file.file_name);

        if source.exists() {
          fs::copy(&source, &dest)?;
          if let Some(ui) = &context.ui {
            ui.println(format!("fetched {} (local)", file.file_name));
          }
          log::info!("fetched {} (local)", file.file_name);
        } else if !file.url.is_empty() {
          download_file(
            &context.base_path,
            &type_dir,
            &file.file_name,
            &file.url,
            curseforge_key.as_deref(),
            modrinth_token.as_deref(),
          )
          .await?;

          // Copy into export dir after ensuring it is present in base dir
          let downloaded =
            context.base_path.join(&type_dir).join(&file.file_name);
          if downloaded.exists() {
            fs::copy(&downloaded, &dest)?;
            if let Some(ui) = &context.ui {
              ui.println(format!("fetched {} (download)", file.file_name));
            }
            log::info!("fetched {} (download)", file.file_name);
          } else {
            return Err(crate::error::PakkerError::InternalError(format!(
              "download reported success but file is missing: {}",
              file.file_name
            )));
          }
        } else {
          return Err(crate::error::PakkerError::InternalError(format!(
            "missing project file and no download url: {}",
            file.file_name
          )));
        }
      }
    }

    Ok(())
  }
}

#[derive(Debug)]
enum DownloadFailure {
  Auth(String),
  Retryable(String),
  Fatal(String),
}

fn classify_response(
  status: reqwest::StatusCode,
  body: &str,
) -> DownloadFailure {
  if status == reqwest::StatusCode::UNAUTHORIZED
    || status == reqwest::StatusCode::FORBIDDEN
  {
    return DownloadFailure::Auth(format!(
      "http {}: {}",
      status.as_u16(),
      body
    ));
  }

  if status == reqwest::StatusCode::TOO_MANY_REQUESTS
    || status.is_server_error()
  {
    return DownloadFailure::Retryable(format!(
      "http {}: {}",
      status.as_u16(),
      body
    ));
  }

  DownloadFailure::Fatal(format!("http {}: {}", status.as_u16(), body))
}

fn classify_reqwest_error(err: &reqwest::Error) -> DownloadFailure {
  if err.is_timeout() || err.is_connect() {
    return DownloadFailure::Retryable(err.to_string());
  }

  DownloadFailure::Fatal(err.to_string())
}

async fn download_file(
  base_path: &std::path::Path,
  type_dir: &str,
  file_name: &str,
  url: &str,
  curseforge_key: Option<&str>,
  modrinth_token: Option<&str>,
) -> Result<()> {
  if url.is_empty() {
    return Err(crate::error::PakkerError::InternalError(format!(
      "cannot download empty url for {file_name}"
    )));
  }

  let client = reqwest::ClientBuilder::new()
    .redirect(reqwest::redirect::Policy::default())
    .build()?;

  let mut request_builder = client.get(url);

  // Credentials are optional for direct file downloads; only attach them when
  // available. Hard failures are determined via HTTP status codes (401/403)
  // during the request.
  if url.contains("curseforge") {
    if let Some(key) = curseforge_key {
      request_builder = request_builder.header("x-api-key", key);
    }
  } else if url.contains("modrinth")
    && let Some(token) = modrinth_token
  {
    request_builder = request_builder.header("Authorization", token);
  }

  let attempts: usize = 5;

  for attempt in 1..=attempts {
    let response = request_builder.try_clone().unwrap().send().await;

    match response {
      Ok(resp) if resp.status().is_success() => {
        let bytes = resp.bytes().await?;
        let target_dir = base_path.join(type_dir);
        fs::create_dir_all(&target_dir)?;
        let dest = target_dir.join(file_name);
        std::fs::write(&dest, &bytes)?;
        return Ok(());
      },
      Ok(resp) => {
        let status = resp.status();
        let body = resp.text().await.unwrap_or_default();
        match classify_response(status, &body) {
          DownloadFailure::Auth(msg) => {
            return Err(crate::error::PakkerError::InternalError(format!(
              "authentication error while downloading {file_name}: {msg}"
            )));
          },
          DownloadFailure::Retryable(msg) => {
            if attempt == attempts {
              return Err(crate::error::PakkerError::InternalError(format!(
                "retryable download error (attempts exhausted) for \
                 {file_name}: {msg}"
              )));
            }
            tokio::time::sleep(std::time::Duration::from_millis(
              250u64.saturating_mul(attempt as u64),
            ))
            .await;
          },
          DownloadFailure::Fatal(msg) => {
            return Err(crate::error::PakkerError::InternalError(format!(
              "download failed for {file_name}: {msg}"
            )));
          },
        }
      },
      Err(err) => {
        match classify_reqwest_error(&err) {
          DownloadFailure::Retryable(msg) => {
            if attempt == attempts {
              return Err(crate::error::PakkerError::InternalError(format!(
                "retryable download error (attempts exhausted) for \
                 {file_name}: {msg}"
              )));
            }
            tokio::time::sleep(std::time::Duration::from_millis(
              250u64.saturating_mul(attempt as u64),
            ))
            .await;
          },
          DownloadFailure::Fatal(msg) | DownloadFailure::Auth(msg) => {
            return Err(crate::error::PakkerError::InternalError(format!(
              "download error for {file_name}: {msg}"
            )));
          },
        }
      },
    }
  }

  Err(crate::error::PakkerError::InternalError(format!(
    "download failed for {file_name} (unknown error)"
  )))
}

// Rule: Copy overrides
pub struct CopyOverridesRule;

impl Rule for CopyOverridesRule {
  fn matches(&self, _context: &RuleContext) -> bool {
    true
  }

  fn effects(&self) -> Vec<Box<dyn Effect>> {
    vec![Box::new(CopyOverridesEffect)]
  }
}

pub struct CopyOverridesEffect;

#[async_trait]
impl Effect for CopyOverridesEffect {
  fn name(&self) -> &'static str {
    "Copying override files"
  }

  async fn execute(&self, context: &RuleContext) -> Result<()> {
    // Use profile-specific overrides if available, otherwise use global config
    let overrides = if let Some(profile_config) = &context.profile_config {
      profile_config.get_overrides(&context.config.overrides)
    } else {
      &context.config.overrides
    };

    // Expand any glob patterns in override paths
    let expanded_paths = expand_override_globs(&context.base_path, overrides);

    for override_path in expanded_paths {
      let source = context.base_path.join(&override_path);
      if !source.exists() {
        continue;
      }

      let dest = context.export_path.join(&override_path);
      copy_recursive(&source, &dest)?;
    }

    Ok(())
  }
}

// Rule: Copy server overrides
pub struct CopyServerOverridesRule;

impl Rule for CopyServerOverridesRule {
  fn matches(&self, context: &RuleContext) -> bool {
    context.config.server_overrides.is_some()
  }

  fn effects(&self) -> Vec<Box<dyn Effect>> {
    vec![Box::new(CopyServerOverridesEffect)]
  }
}

pub struct CopyServerOverridesEffect;

#[async_trait]
impl Effect for CopyServerOverridesEffect {
  fn name(&self) -> &'static str {
    "Copying server override files"
  }

  async fn execute(&self, context: &RuleContext) -> Result<()> {
    // Use profile-specific server overrides if available, otherwise use global
    // config
    let server_overrides = if let Some(profile_config) = &context.profile_config
    {
      profile_config
        .get_server_overrides(context.config.server_overrides.as_ref())
    } else {
      context.config.server_overrides.as_deref()
    };

    if let Some(overrides) = server_overrides {
      // Expand any glob patterns in override paths
      let expanded_paths = expand_override_globs(&context.base_path, overrides);

      for override_path in expanded_paths {
        let source = context.base_path.join(&override_path);
        if !source.exists() {
          continue;
        }

        let dest = context.export_path.join(&override_path);
        copy_recursive(&source, &dest)?;
      }
    }

    Ok(())
  }
}

// Rule: Copy client overrides
pub struct CopyClientOverridesRule;

impl Rule for CopyClientOverridesRule {
  fn matches(&self, context: &RuleContext) -> bool {
    context.config.client_overrides.is_some()
  }

  fn effects(&self) -> Vec<Box<dyn Effect>> {
    vec![Box::new(CopyClientOverridesEffect)]
  }
}

pub struct CopyClientOverridesEffect;

#[async_trait]
impl Effect for CopyClientOverridesEffect {
  fn name(&self) -> &'static str {
    "Copying client override files"
  }

  async fn execute(&self, context: &RuleContext) -> Result<()> {
    // Use profile-specific client overrides if available, otherwise use global
    // config
    let client_overrides = if let Some(profile_config) = &context.profile_config
    {
      profile_config
        .get_client_overrides(context.config.client_overrides.as_ref())
    } else {
      context.config.client_overrides.as_deref()
    };

    if let Some(overrides) = client_overrides {
      // Expand any glob patterns in override paths
      let expanded_paths = expand_override_globs(&context.base_path, overrides);

      for override_path in expanded_paths {
        let source = context.base_path.join(&override_path);
        if !source.exists() {
          continue;
        }

        let dest = context.export_path.join(&override_path);
        copy_recursive(&source, &dest)?;
      }
    }

    Ok(())
  }
}

// Rule: Filter client-only projects (for server packs)
pub struct FilterClientOnlyRule;

impl Rule for FilterClientOnlyRule {
  fn matches(&self, _context: &RuleContext) -> bool {
    true
  }

  fn effects(&self) -> Vec<Box<dyn Effect>> {
    vec![Box::new(FilterClientOnlyEffect)]
  }
}

pub struct FilterClientOnlyEffect;

#[async_trait]
impl Effect for FilterClientOnlyEffect {
  fn name(&self) -> &'static str {
    "Filtering client-only projects"
  }

  async fn execute(&self, context: &RuleContext) -> Result<()> {
    // Check if we should include client-only mods (profile config can override)
    let include_client_only = context
      .profile_config
      .as_ref()
      .and_then(|pc| pc.include_client_only)
      .unwrap_or(false);

    if include_client_only {
      // Don't filter anything
      return Ok(());
    }

    for project in &context.lockfile.projects {
      if project.side == ProjectSide::Client
        && let Some(file) = project.files.first()
      {
        // Get the target directory based on project type and paths config
        let type_dir = get_project_type_dir(&project.r#type, &context.config);
        let project_dir = context.export_path.join(&type_dir);
        let file_path = project_dir.join(&file.file_name);

        if file_path.exists() {
          fs::remove_file(&file_path)?;
          log::info!("Filtered client-only project: {}", file.file_name);
        }
      }
    }

    Ok(())
  }
}

// Rule: Filter server-only projects (for client packs)
// This rule respects the `export_server_side_projects_to_client` config option
pub struct FilterServerOnlyRule;

impl Rule for FilterServerOnlyRule {
  fn matches(&self, _context: &RuleContext) -> bool {
    true
  }

  fn effects(&self) -> Vec<Box<dyn Effect>> {
    vec![Box::new(FilterServerOnlyEffect)]
  }
}

pub struct FilterServerOnlyEffect;

#[async_trait]
impl Effect for FilterServerOnlyEffect {
  fn name(&self) -> &'static str {
    "Filtering server-only projects"
  }

  async fn execute(&self, context: &RuleContext) -> Result<()> {
    // Check config option: if true, include server-side projects in client
    // exports
    let export_server_to_client = context
      .config
      .export_server_side_projects_to_client
      .unwrap_or(false);

    if export_server_to_client {
      // Don't filter server-only mods - include them in client pack
      return Ok(());
    }

    for project in &context.lockfile.projects {
      if project.side == ProjectSide::Server
        && let Some(file) = project.files.first()
      {
        // Get the target directory based on project type and paths config
        let type_dir = get_project_type_dir(&project.r#type, &context.config);
        let project_dir = context.export_path.join(&type_dir);
        let file_path = project_dir.join(&file.file_name);

        if file_path.exists() {
          fs::remove_file(&file_path)?;
          log::info!(
            "Filtered server-only project: {} \
             (export_server_side_projects_to_client=false)",
            file.file_name
          );
        }
      }
    }

    Ok(())
  }
}

// Rule: Filter non-redistributable
pub struct FilterNonRedistributableRule;

impl Rule for FilterNonRedistributableRule {
  fn matches(&self, _context: &RuleContext) -> bool {
    true
  }

  fn effects(&self) -> Vec<Box<dyn Effect>> {
    vec![Box::new(FilterNonRedistributableEffect)]
  }
}

pub struct FilterNonRedistributableEffect;

#[async_trait]
impl Effect for FilterNonRedistributableEffect {
  fn name(&self) -> &'static str {
    "Filtering non-redistributable projects"
  }

  async fn execute(&self, context: &RuleContext) -> Result<()> {
    // Check if we should include non-redistributable mods (profile config can
    // override)
    let include_non_redistributable = context
      .profile_config
      .as_ref()
      .and_then(|pc| pc.include_non_redistributable)
      .unwrap_or(false);

    if include_non_redistributable {
      // Don't filter anything
      return Ok(());
    }

    for project in &context.lockfile.projects {
      if !project.redistributable
        && let Some(file) = project.files.first()
      {
        // Get the target directory based on project type and paths config
        let type_dir = get_project_type_dir(&project.r#type, &context.config);
        let project_dir = context.export_path.join(&type_dir);
        let file_path = project_dir.join(&file.file_name);

        if file_path.exists() {
          fs::remove_file(&file_path)?;
          log::info!("Filtered non-redistributable: {}", file.file_name);
        }
      }
    }

    Ok(())
  }
}

// Rule: Generate manifest
pub struct GenerateManifestRule {
  platform: String,
}

impl GenerateManifestRule {
  pub fn curseforge() -> Self {
    Self {
      platform: "curseforge".to_string(),
    }
  }

  pub fn modrinth() -> Self {
    Self {
      platform: "modrinth".to_string(),
    }
  }
}

impl Rule for GenerateManifestRule {
  fn matches(&self, _context: &RuleContext) -> bool {
    true
  }

  fn effects(&self) -> Vec<Box<dyn Effect>> {
    vec![Box::new(GenerateManifestEffect {
      platform: self.platform.clone(),
    })]
  }
}

pub struct GenerateManifestEffect {
  platform: String,
}

#[async_trait]
impl Effect for GenerateManifestEffect {
  fn name(&self) -> &'static str {
    "Generating manifest file"
  }

  async fn execute(&self, context: &RuleContext) -> Result<()> {
    let (manifest, filename) = if self.platform == "curseforge" {
      (generate_curseforge_manifest(context)?, "manifest.json")
    } else if self.platform == "modrinth" {
      (generate_modrinth_manifest(context)?, "modrinth.index.json")
    } else {
      return Ok(());
    };

    let manifest_path = context.export_path.join(filename);
    fs::write(manifest_path, manifest)?;

    Ok(())
  }
}

fn generate_curseforge_manifest(context: &RuleContext) -> Result<String> {
  use serde_json::json;

  let files: Vec<_> = context
    .lockfile
    .projects
    .iter()
    .filter(|p| p.export)
    .filter_map(|p| {
      p.get_platform_id("curseforge").and_then(|id| {
        p.files.first().map(|f| {
          json!({
              "projectID": id.parse::<u32>().unwrap_or(0),
              "fileID": f.id.parse::<u32>().unwrap_or(0),
              "required": true
          })
        })
      })
    })
    .collect();

  let manifest = json!({
      "minecraft": {
          "version": context.lockfile.mc_versions.first().unwrap_or(&"1.20.1".to_string()),
          "modLoaders": context.lockfile.loaders.iter().map(|(name, version)| {
              json!({
                  "id": format!("{}-{}", name, version),
                  "primary": true
              })
          }).collect::<Vec<_>>()
      },
      "manifestType": "minecraftModpack",
      "manifestVersion": 1,
      "name": context.config.name,
      "version": context.config.version,
      "author": context.config.author.clone().unwrap_or_default(),
      "files": files,
      "overrides": "overrides"
  });

  Ok(serde_json::to_string_pretty(&manifest)?)
}

fn generate_modrinth_manifest(context: &RuleContext) -> Result<String> {
  use serde_json::json;

  let files: Vec<_> = context
    .lockfile
    .projects
    .iter()
    .filter(|p| p.export)
    .filter_map(|p| {
      p.get_platform_id("modrinth").and_then(|_id| {
        p.files.first().map(|f| {
          let mut env = serde_json::Map::new();
          match p.side {
            crate::model::ProjectSide::Client => {
              env.insert("client".to_string(), json!("required"));
              env.insert("server".to_string(), json!("unsupported"));
            },
            crate::model::ProjectSide::Server => {
              env.insert("client".to_string(), json!("unsupported"));
              env.insert("server".to_string(), json!("required"));
            },
            crate::model::ProjectSide::Both => {
              env.insert("client".to_string(), json!("required"));
              env.insert("server".to_string(), json!("required"));
            },
          }

          json!({
              "path": format!("mods/{}", f.file_name),
              "hashes": f.hashes,
              "env": env,
              "downloads": [f.url.clone()],
              "fileSize": f.size
          })
        })
      })
    })
    .collect();

  // Build dependencies dynamically based on loaders present
  let mut dependencies = serde_json::Map::new();
  dependencies.insert(
    "minecraft".to_string(),
    json!(
      context
        .lockfile
        .mc_versions
        .first()
        .unwrap_or(&"1.20.1".to_string())
    ),
  );

  for (loader_name, loader_version) in &context.lockfile.loaders {
    let dep_key = format!("{loader_name}-loader");
    dependencies.insert(dep_key, json!(loader_version));
  }

  let manifest = json!({
      "formatVersion": 1,
      "game": "minecraft",
      "versionId": context.config.version,
      "name": context.config.name,
      "summary": context.config.description.clone().unwrap_or_default(),
      "files": files,
      "dependencies": dependencies
  });

  Ok(serde_json::to_string_pretty(&manifest)?)
}

fn copy_recursive(
  source: &std::path::Path,
  dest: &std::path::Path,
) -> Result<()> {
  if source.is_file() {
    if let Some(parent) = dest.parent() {
      fs::create_dir_all(parent)?;
    }
    fs::copy(source, dest)?;
  } else if source.is_dir() {
    fs::create_dir_all(dest)?;
    for entry in fs::read_dir(source)? {
      let entry = entry?;
      let target = dest.join(entry.file_name());
      copy_recursive(&entry.path(), &target)?;
    }
  }

  Ok(())
}

/// Get the target directory for a project type, respecting the paths config.
/// Falls back to default directories if not configured.
fn get_project_type_dir(project_type: &ProjectType, config: &Config) -> String {
  // Check if there's a custom path configured for this project type
  let type_key = project_type.to_string();
  if let Some(custom_path) = config.paths.get(&type_key) {
    return custom_path.clone();
  }

  // Fall back to default paths
  match project_type {
    ProjectType::Mod => "mods".to_string(),
    ProjectType::ResourcePack => "resourcepacks".to_string(),
    ProjectType::DataPack => "datapacks".to_string(),
    ProjectType::Shader => "shaderpacks".to_string(),
    ProjectType::World => "saves".to_string(),
  }
}

/// Expand glob patterns in override paths and return all matching paths.
/// If a path contains no glob characters, it's returned as-is (if it exists).
/// Glob patterns are relative to the `base_path`.
fn expand_override_globs(
  base_path: &std::path::Path,
  override_paths: &[String],
) -> Vec<PathBuf> {
  let mut results = Vec::new();

  for override_path in override_paths {
    // Check if the path contains glob characters
    let has_glob = override_path.contains('*')
      || override_path.contains('?')
      || override_path.contains('[');

    if has_glob {
      // Expand the glob pattern relative to base_path
      let pattern = base_path.join(override_path);
      let pattern_str = pattern.to_string_lossy();

      match glob(&pattern_str) {
        Ok(paths) => {
          for entry in paths.flatten() {
            // Store the path relative to base_path for consistent handling
            if let Ok(relative) = entry.strip_prefix(base_path) {
              results.push(relative.to_path_buf());
            } else {
              results.push(entry);
            }
          }
        },
        Err(e) => {
          log::warn!("Invalid glob pattern '{override_path}': {e}");
        },
      }
    } else {
      // Not a glob pattern - use as-is
      results.push(PathBuf::from(override_path));
    }
  }

  results
}

// Rule: Filter projects by platform
pub struct FilterByPlatformRule;

impl Rule for FilterByPlatformRule {
  fn matches(&self, context: &RuleContext) -> bool {
    // Only match if profile config specifies a platform filter
    context
      .profile_config
      .as_ref()
      .and_then(|pc| pc.filter_platform.as_ref())
      .is_some()
  }

  fn effects(&self) -> Vec<Box<dyn Effect>> {
    vec![Box::new(FilterByPlatformEffect)]
  }
}

pub struct FilterByPlatformEffect;

#[async_trait]
impl Effect for FilterByPlatformEffect {
  fn name(&self) -> &'static str {
    "Filtering projects by platform availability"
  }

  async fn execute(&self, context: &RuleContext) -> Result<()> {
    if let Some(profile_config) = &context.profile_config
      && let Some(platform) = &profile_config.filter_platform
    {
      for project in &context.lockfile.projects {
        // Check if project is available on the target platform
        let has_platform = project.get_platform_id(platform).is_some();

        if !has_platform {
          // Remove the file if it was copied
          if let Some(file) = project.files.first() {
            // Get the target directory based on project type and paths config
            let type_dir =
              get_project_type_dir(&project.r#type, &context.config);
            let project_dir = context.export_path.join(&type_dir);
            let file_path = project_dir.join(&file.file_name);

            if file_path.exists() {
              fs::remove_file(&file_path)?;
              log::info!(
                "Filtered {} (not available on {})",
                file.file_name,
                platform
              );
            }
          }
        }
      }
    }

    Ok(())
  }
}

// Rule: Export missing projects as overrides
// When a project is not available on the target platform, download it and
// include as an override file instead
pub struct MissingProjectsAsOverridesRule {
  target_platform: String,
}

impl MissingProjectsAsOverridesRule {
  pub fn new(target_platform: &str) -> Self {
    Self {
      target_platform: target_platform.to_string(),
    }
  }
}

impl Rule for MissingProjectsAsOverridesRule {
  fn matches(&self, _context: &RuleContext) -> bool {
    true
  }

  fn effects(&self) -> Vec<Box<dyn Effect>> {
    vec![Box::new(MissingProjectsAsOverridesEffect {
      target_platform: self.target_platform.clone(),
    })]
  }
}

pub struct MissingProjectsAsOverridesEffect {
  target_platform: String,
}

#[async_trait]
impl Effect for MissingProjectsAsOverridesEffect {
  fn name(&self) -> &'static str {
    "Exporting missing projects as overrides"
  }

  async fn execute(&self, context: &RuleContext) -> Result<()> {
    use crate::model::ResolvedCredentials;

    let credentials = ResolvedCredentials::load().ok();
    let curseforge_key = credentials
      .as_ref()
      .and_then(|c| c.curseforge_api_key().map(ToOwned::to_owned));
    let modrinth_token = credentials
      .as_ref()
      .and_then(|c| c.modrinth_token().map(ToOwned::to_owned));

    for project in &context.lockfile.projects {
      if !project.export {
        continue;
      }

      // Check if project is available on target platform
      let has_target_platform =
        project.get_platform_id(&self.target_platform).is_some();

      if has_target_platform {
        // Project is available on target platform, skip
        continue;
      }

      // Project is missing on target platform - export as override
      if let Some(file) = project.files.first() {
        // Find a download URL from any available platform
        if file.url.is_empty() {
          log::warn!(
            "Missing project '{}' has no download URL, skipping",
            project.get_name()
          );
          continue;
        }

        // Download to overrides directory
        let overrides_dir = context.export_path.join("overrides");
        let type_dir = get_project_type_dir(&project.r#type, &context.config);
        let target_dir = overrides_dir.join(&type_dir);
        fs::create_dir_all(&target_dir)?;

        let dest = target_dir.join(&file.file_name);

        // Download the file
        let client = reqwest::Client::new();
        let mut request = client.get(&file.url);

        // Add auth headers if needed
        if file.url.contains("curseforge") {
          if let Some(ref key) = curseforge_key {
            request = request.header("x-api-key", key);
          }
        } else if file.url.contains("modrinth")
          && let Some(ref token) = modrinth_token
        {
          request = request.header("Authorization", token);
        }

        match request.send().await {
          Ok(resp) if resp.status().is_success() => {
            let bytes = resp.bytes().await?;
            fs::write(&dest, &bytes)?;
            log::info!(
              "Exported missing project '{}' as override (not on {})",
              project.get_name(),
              self.target_platform
            );
          },
          Ok(resp) => {
            log::warn!(
              "Failed to download missing project '{}': HTTP {}",
              project.get_name(),
              resp.status()
            );
          },
          Err(e) => {
            log::warn!(
              "Failed to download missing project '{}': {}",
              project.get_name(),
              e
            );
          },
        }
      }
    }

    Ok(())
  }
}

// Rule: Text replacement in exported files
// Replaces template variables like ${MC_VERSION}, ${PACK_NAME}, etc.
pub struct TextReplacementRule;

impl Rule for TextReplacementRule {
  fn matches(&self, _context: &RuleContext) -> bool {
    true
  }

  fn effects(&self) -> Vec<Box<dyn Effect>> {
    vec![Box::new(TextReplacementEffect)]
  }
}

pub struct TextReplacementEffect;

#[async_trait]
impl Effect for TextReplacementEffect {
  fn name(&self) -> &'static str {
    "Applying text replacements"
  }

  async fn execute(&self, context: &RuleContext) -> Result<()> {
    // Build replacement map from context
    let mut replacements: std::collections::HashMap<&str, String> =
      std::collections::HashMap::new();

    // Pack metadata
    replacements.insert("${PACK_NAME}", context.config.name.clone());
    replacements.insert("${PACK_VERSION}", context.config.version.clone());
    replacements.insert(
      "${PACK_AUTHOR}",
      context.config.author.clone().unwrap_or_default(),
    );
    replacements.insert(
      "${PACK_DESCRIPTION}",
      context.config.description.clone().unwrap_or_default(),
    );

    // Minecraft version
    replacements.insert(
      "${MC_VERSION}",
      context
        .lockfile
        .mc_versions
        .first()
        .cloned()
        .unwrap_or_default(),
    );
    replacements
      .insert("${MC_VERSIONS}", context.lockfile.mc_versions.join(", "));

    // Loader info
    if let Some((name, version)) = context.lockfile.loaders.iter().next() {
      replacements.insert("${LOADER}", name.clone());
      replacements.insert("${LOADER_VERSION}", version.clone());
    }

    // All loaders
    replacements.insert(
      "${LOADERS}",
      context
        .lockfile
        .loaders
        .iter()
        .map(|(k, v)| format!("{k}={v}"))
        .collect::<Vec<_>>()
        .join(", "),
    );

    // Project count
    replacements.insert(
      "${PROJECT_COUNT}",
      context.lockfile.projects.len().to_string(),
    );
    replacements.insert(
      "${MOD_COUNT}",
      context
        .lockfile
        .projects
        .iter()
        .filter(|p| p.r#type == ProjectType::Mod)
        .count()
        .to_string(),
    );

    // Process text files in the export directory
    process_text_files(&context.export_path, &replacements)?;

    Ok(())
  }
}

/// Process text files in a directory, applying replacements
fn process_text_files(
  dir: &std::path::Path,
  replacements: &std::collections::HashMap<&str, String>,
) -> Result<()> {
  if !dir.exists() {
    return Ok(());
  }

  // File extensions that should be processed for text replacement
  const TEXT_EXTENSIONS: &[&str] = &[
    "txt",
    "md",
    "json",
    "toml",
    "yaml",
    "yml",
    "cfg",
    "conf",
    "properties",
    "lang",
    "mcmeta",
    "html",
    "htm",
    "xml",
  ];

  for entry in walkdir::WalkDir::new(dir)
    .into_iter()
    .filter_map(std::result::Result::ok)
    .filter(|e| e.file_type().is_file())
  {
    let path = entry.path();

    // Check if file extension is in our list
    let should_process = path
      .extension()
      .and_then(|ext| ext.to_str())
      .is_some_and(|ext| {
        TEXT_EXTENSIONS.contains(&ext.to_lowercase().as_str())
      });

    if !should_process {
      continue;
    }

    // Read file content
    let content = match fs::read_to_string(path) {
      Ok(c) => c,
      Err(_) => continue, // Skip binary files or unreadable files
    };

    // Check if any replacements are needed
    let needs_replacement =
      replacements.keys().any(|key| content.contains(*key));

    if !needs_replacement {
      continue;
    }

    // Apply replacements
    let mut new_content = content;
    for (pattern, replacement) in replacements {
      new_content = new_content.replace(*pattern, replacement);
    }

    // Write back
    fs::write(path, new_content)?;
    log::debug!("Applied text replacements to: {}", path.display());
  }

  Ok(())
}

#[cfg(test)]
mod tests {
  use std::collections::HashMap;

  use super::*;
  use crate::{export::ProfileConfig, model::LockFile};

  fn create_test_context(profile_config: Option<ProfileConfig>) -> RuleContext {
    let mut loaders = HashMap::new();
    loaders.insert("fabric".to_string(), "0.15.0".to_string());

    RuleContext {
      lockfile: LockFile {
        target: None,
        projects: vec![],
        mc_versions: vec!["1.20.1".to_string()],
        loaders,
        lockfile_version: 1,
      },
      config: Config {
        name:                                  "Test Pack".to_string(),
        version:                               "1.0.0".to_string(),
        description:                           None,
        author:                                None,
        overrides:                             vec!["overrides".to_string()],
        server_overrides:                      Some(vec![
          "server-overrides".to_string(),
        ]),
        client_overrides:                      Some(vec![
          "client-overrides".to_string(),
        ]),
        paths:                                 HashMap::new(),
        projects:                              None,
        export_profiles:                       None,
        export_server_side_projects_to_client: None,
        file_count_preference:                 None,
      },
      profile_config,
      export_path: PathBuf::from("/tmp/export"),
      base_path: PathBuf::from("/tmp/base"),
      ui: None,
    }
  }

  #[test]
  fn test_filter_by_platform_rule_matches_with_platform_filter() {
    let profile_config = ProfileConfig {
      filter_platform: Some("modrinth".to_string()),
      ..Default::default()
    };
    let context = create_test_context(Some(profile_config));
    let rule = FilterByPlatformRule;

    assert!(rule.matches(&context));
  }

  #[test]
  fn test_filter_by_platform_rule_no_match_without_platform_filter() {
    let context = create_test_context(None);
    let rule = FilterByPlatformRule;

    assert!(!rule.matches(&context));
  }

  #[test]
  fn test_filter_by_platform_rule_no_match_with_empty_profile_config() {
    let profile_config = ProfileConfig::default();
    let context = create_test_context(Some(profile_config));
    let rule = FilterByPlatformRule;

    assert!(!rule.matches(&context));
  }

  #[test]
  fn test_copy_overrides_uses_profile_config() {
    let profile_config = ProfileConfig {
      overrides: Some(vec!["custom-overrides".to_string()]),
      ..Default::default()
    };
    let context = create_test_context(Some(profile_config));

    assert!(context.profile_config.is_some());
    assert_eq!(
      context
        .profile_config
        .as_ref()
        .unwrap()
        .overrides
        .as_ref()
        .unwrap(),
      &vec!["custom-overrides".to_string()]
    );
  }

  #[test]
  fn test_filter_non_redistributable_respects_profile_config() {
    let profile_config = ProfileConfig {
      include_non_redistributable: Some(true),
      ..Default::default()
    };
    let context = create_test_context(Some(profile_config));

    assert_eq!(
      context
        .profile_config
        .as_ref()
        .unwrap()
        .include_non_redistributable,
      Some(true)
    );
  }

  #[test]
  fn test_filter_client_only_respects_profile_config() {
    let profile_config = ProfileConfig {
      include_client_only: Some(true),
      ..Default::default()
    };
    let context = create_test_context(Some(profile_config));

    assert_eq!(
      context.profile_config.as_ref().unwrap().include_client_only,
      Some(true)
    );
  }

  #[test]
  fn test_server_overrides_uses_profile_config() {
    let profile_config = ProfileConfig {
      server_overrides: Some(vec!["custom-server-overrides".to_string()]),
      ..Default::default()
    };
    let context = create_test_context(Some(profile_config));

    let server_overrides = context
      .profile_config
      .as_ref()
      .unwrap()
      .get_server_overrides(context.config.server_overrides.as_ref());

    assert!(server_overrides.is_some());
    assert_eq!(server_overrides.unwrap(), &["custom-server-overrides"]);
  }

  #[test]
  fn test_profile_config_fallback_to_global() {
    let context = create_test_context(None);

    assert!(context.profile_config.is_none());
    assert_eq!(context.config.overrides, vec!["overrides"]);
  }

  #[test]
  fn test_get_project_type_dir_default_paths() {
    let config = Config {
      name:                                  "Test".to_string(),
      version:                               "1.0.0".to_string(),
      description:                           None,
      author:                                None,
      overrides:                             vec![],
      server_overrides:                      None,
      client_overrides:                      None,
      paths:                                 HashMap::new(),
      projects:                              None,
      export_profiles:                       None,
      export_server_side_projects_to_client: None,
      file_count_preference:                 None,
    };

    assert_eq!(get_project_type_dir(&ProjectType::Mod, &config), "mods");
    assert_eq!(
      get_project_type_dir(&ProjectType::ResourcePack, &config),
      "resourcepacks"
    );
    assert_eq!(
      get_project_type_dir(&ProjectType::DataPack, &config),
      "datapacks"
    );
    assert_eq!(
      get_project_type_dir(&ProjectType::Shader, &config),
      "shaderpacks"
    );
    assert_eq!(get_project_type_dir(&ProjectType::World, &config), "saves");
  }

  #[test]
  fn test_get_project_type_dir_custom_paths() {
    let mut paths = HashMap::new();
    paths.insert("mod".to_string(), "custom-mods".to_string());
    paths.insert("resource-pack".to_string(), "custom-rp".to_string());

    let config = Config {
      name: "Test".to_string(),
      version: "1.0.0".to_string(),
      description: None,
      author: None,
      overrides: vec![],
      server_overrides: None,
      client_overrides: None,
      paths,
      projects: None,
      export_profiles: None,
      export_server_side_projects_to_client: None,
      file_count_preference: None,
    };

    assert_eq!(
      get_project_type_dir(&ProjectType::Mod, &config),
      "custom-mods"
    );
    assert_eq!(
      get_project_type_dir(&ProjectType::ResourcePack, &config),
      "custom-rp"
    );
    // Non-customized type should use default
    assert_eq!(
      get_project_type_dir(&ProjectType::Shader, &config),
      "shaderpacks"
    );
  }

  #[test]
  fn test_expand_override_globs_no_globs() {
    let base_path = PathBuf::from("/tmp/test");
    let overrides = vec!["overrides".to_string(), "config".to_string()];

    let result = expand_override_globs(&base_path, &overrides);

    assert_eq!(result.len(), 2);
    assert_eq!(result[0], PathBuf::from("overrides"));
    assert_eq!(result[1], PathBuf::from("config"));
  }

  #[test]
  fn test_expand_override_globs_detects_glob_characters() {
    // Just test that glob characters are detected - actual expansion
    // requires the files to exist
    let base_path = PathBuf::from("/nonexistent");
    let overrides = vec![
      "overrides/*.txt".to_string(),
      "config/**/*.json".to_string(),
      "data/[abc].txt".to_string(),
      "simple".to_string(),
    ];

    let result = expand_override_globs(&base_path, &overrides);

    // Glob patterns that don't match anything return empty
    // Only the non-glob path should be returned as-is
    assert!(result.contains(&PathBuf::from("simple")));
  }

  #[test]
  fn test_client_overrides_rule_matches() {
    let mut config = Config {
      name:                                  "Test".to_string(),
      version:                               "1.0.0".to_string(),
      description:                           None,
      author:                                None,
      overrides:                             vec![],
      server_overrides:                      None,
      client_overrides:                      Some(vec![
        "client-data".to_string(),
      ]),
      paths:                                 HashMap::new(),
      projects:                              None,
      export_profiles:                       None,
      export_server_side_projects_to_client: None,
      file_count_preference:                 None,
    };

    let mut context = create_test_context(None);
    context.config = config.clone();

    let rule = CopyClientOverridesRule;
    assert!(rule.matches(&context));

    // Without client_overrides, should not match
    config.client_overrides = None;
    context.config = config;
    assert!(!rule.matches(&context));
  }

  #[test]
  fn test_server_overrides_rule_matches() {
    let mut config = Config {
      name:                                  "Test".to_string(),
      version:                               "1.0.0".to_string(),
      description:                           None,
      author:                                None,
      overrides:                             vec![],
      server_overrides:                      Some(vec![
        "server-data".to_string(),
      ]),
      client_overrides:                      None,
      paths:                                 HashMap::new(),
      projects:                              None,
      export_profiles:                       None,
      export_server_side_projects_to_client: None,
      file_count_preference:                 None,
    };

    let mut context = create_test_context(None);
    context.config = config.clone();

    let rule = CopyServerOverridesRule;
    assert!(rule.matches(&context));

    // Without server_overrides, should not match
    config.server_overrides = None;
    context.config = config;
    assert!(!rule.matches(&context));
  }

  #[test]
  fn test_filter_server_only_rule_always_matches() {
    let context = create_test_context(None);
    let rule = FilterServerOnlyRule;
    assert!(rule.matches(&context));
  }

  #[test]
  fn test_text_replacement_rule_always_matches() {
    let context = create_test_context(None);
    let rule = TextReplacementRule;
    assert!(rule.matches(&context));
  }

  #[test]
  fn test_missing_projects_rule_always_matches() {
    let context = create_test_context(None);
    let rule = MissingProjectsAsOverridesRule::new("modrinth");
    assert!(rule.matches(&context));
  }
}