use std::path::Path;

use crate::{
  cli::ImportArgs,
  error::{PakkerError, Result},
  model::{Config, LockFile, Target},
  ui_utils::prompt_yes_no,
};

pub async fn execute(
  args: ImportArgs,
  global_yes: bool,
  lockfile_path: &Path,
  config_path: &Path,
) -> Result<()> {
  let skip_prompts = global_yes;
  log::info!("Importing modpack from {}", args.file);
  log::info!(
    "Dependency resolution: {}",
    if args.deps { "enabled" } else { "disabled" }
  );

  let path = Path::new(&args.file);

  if !path.exists() {
    return Err(PakkerError::FileNotFound(
      path.to_string_lossy().to_string(),
    ));
  }

  // Check if lockfile or config already exist
  if (lockfile_path.exists() || config_path.exists()) && !skip_prompts {
    let msg = if lockfile_path.exists() && config_path.exists() {
      "Both pakku-lock.json and pakku.json exist. Importing will overwrite \
       them. Continue?"
    } else if lockfile_path.exists() {
      "pakku-lock.json exists. Importing will overwrite it. Continue?"
    } else {
      "pakku.json exists. Importing will overwrite it. Continue?"
    };

    if !prompt_yes_no(msg, false, skip_prompts)? {
      log::info!("Import cancelled by user");
      return Ok(());
    }
  }

  // Detect format by checking file contents
  let file = std::fs::File::open(path)?;
  let mut archive = zip::ZipArchive::new(file)?;

  let lockfile_dir = lockfile_path.parent().unwrap_or(Path::new("."));
  let config_dir = config_path.parent().unwrap_or(Path::new("."));

  if archive.by_name("modrinth.index.json").is_ok() {
    drop(archive);
    import_modrinth(path, lockfile_dir, config_dir).await
  } else if archive.by_name("manifest.json").is_ok() {
    drop(archive);
    import_curseforge(path, lockfile_dir, config_dir).await
  } else {
    Err(PakkerError::InvalidImportFile(
      "Unknown pack format".to_string(),
    ))
  }
}

async fn import_modrinth(
  path: &Path,
  lockfile_dir: &Path,
  config_dir: &Path,
) -> Result<()> {
  use std::{fs::File, io::Read};

  use zip::ZipArchive;

  use crate::platform::create_platform;

  let file = File::open(path)?;
  let mut archive = ZipArchive::new(file)?;

  let index_content = {
    let mut index_file = archive.by_name("modrinth.index.json")?;
    let mut content = String::new();
    index_file.read_to_string(&mut content)?;
    content
  };

  let index: serde_json::Value = serde_json::from_str(&index_content)?;

  // Create lockfile
  let mc_version = index["dependencies"]["minecraft"]
    .as_str()
    .unwrap_or("1.20.1")
    .to_string();

  let loader =
    if let Some(fabric) = index["dependencies"]["fabric-loader"].as_str() {
      ("fabric".to_string(), fabric.to_string())
    } else if let Some(forge) = index["dependencies"]["forge"].as_str() {
      ("forge".to_string(), forge.to_string())
    } else {
      ("fabric".to_string(), "latest".to_string())
    };

  let mut loaders = std::collections::HashMap::new();
  loaders.insert(loader.0.clone(), loader.1);

  let mut lockfile = LockFile {
    target:           Some(Target::Modrinth),
    mc_versions:      vec![mc_version.clone()],
    loaders:          loaders.clone(),
    projects:         Vec::new(),
    lockfile_version: 1,
  };

  // Import projects from files list
  if let Some(files) = index["files"].as_array() {
    log::info!("Importing {} projects from modpack", files.len());

    // Create platform client
    let creds = crate::model::credentials::ResolvedCredentials::load().ok();
    let platform = create_platform(
      "modrinth",
      creds
        .as_ref()
        .and_then(|c| c.modrinth_token().map(std::string::ToString::to_string)),
    )?;

    for file_entry in files {
      if let Some(project_id) = file_entry["downloads"]
        .as_array()
        .and_then(|downloads| downloads.first())
        .and_then(|url| url.as_str())
        .and_then(|url| url.split('/').rev().nth(1))
      {
        log::info!("Fetching project: {project_id}");
        match platform
          .request_project_with_files(
            project_id,
            &lockfile.mc_versions,
            std::slice::from_ref(&loader.0),
          )
          .await
        {
          Ok(mut project) => {
            // Select best file
            if let Err(e) = project.select_file(
              &lockfile.mc_versions,
              std::slice::from_ref(&loader.0),
              None, // Use default (1 file) during import
            ) {
              log::warn!(
                "Failed to select file for {}: {}",
                project.get_name(),
                e
              );
              continue;
            }
            lockfile.add_project(project);
          },
          Err(e) => {
            log::warn!("Failed to fetch project {project_id}: {e}");
          },
        }
      }
    }
  }

  // Create config
  let config = Config {
    name:                                  index["name"]
      .as_str()
      .unwrap_or("Imported Pack")
      .to_string(),
    version:                               index["versionId"]
      .as_str()
      .unwrap_or("1.0.0")
      .to_string(),
    description:                           index["summary"]
      .as_str()
      .map(std::string::ToString::to_string),
    author:                                None,
    overrides:                             vec!["overrides".to_string()],
    server_overrides:                      None,
    client_overrides:                      None,
    paths:                                 Default::default(),
    projects:                              None,
    export_profiles:                       None,
    export_server_side_projects_to_client: None,
    file_count_preference:                 None,
  };

  // Save files using provided paths
  lockfile.save(lockfile_dir)?;
  config.save(config_dir)?;

  log::info!("Imported {} projects", lockfile.projects.len());

  // Extract overrides
  for i in 0..archive.len() {
    let mut file = archive.by_index(i)?;
    let outpath = file.enclosed_name().ok_or_else(|| {
      PakkerError::InternalError("Invalid file path in archive".to_string())
    })?;

    if outpath.starts_with("overrides/") {
      let target = outpath.strip_prefix("overrides/").unwrap();

      if file.is_dir() {
        std::fs::create_dir_all(target)?;
      } else {
        if let Some(parent) = target.parent() {
          std::fs::create_dir_all(parent)?;
        }
        let mut outfile = File::create(target)?;
        std::io::copy(&mut file, &mut outfile)?;
      }
    }
  }

  Ok(())
}

async fn import_curseforge(
  path: &Path,
  lockfile_dir: &Path,
  config_dir: &Path,
) -> Result<()> {
  use std::{fs::File, io::Read};

  use zip::ZipArchive;

  let file = File::open(path)?;
  let mut archive = ZipArchive::new(file)?;

  let manifest_content = {
    let mut manifest_file = archive.by_name("manifest.json")?;
    let mut content = String::new();
    manifest_file.read_to_string(&mut content)?;
    content
  };

  let manifest: serde_json::Value = serde_json::from_str(&manifest_content)?;

  // Create lockfile
  let mc_version = manifest["minecraft"]["version"]
    .as_str()
    .unwrap_or("1.20.1")
    .to_string();

  let mod_loaders =
    manifest["minecraft"]["modLoaders"]
      .as_array()
      .ok_or_else(|| {
        PakkerError::InvalidImportFile("Missing modLoaders".to_string())
      })?;

  let loader_info = mod_loaders
    .first()
    .and_then(|l| l["id"].as_str())
    .ok_or_else(|| {
      PakkerError::InvalidImportFile("Missing loader id".to_string())
    })?;

  let parts: Vec<&str> = loader_info.split('-').collect();
  let loader_name = (*parts.first().unwrap_or(&"fabric")).to_string();
  let loader_version = (*parts.get(1).unwrap_or(&"latest")).to_string();

  let mut loaders = std::collections::HashMap::new();
  loaders.insert(loader_name, loader_version);

  let mut lockfile = LockFile {
    target:           Some(Target::CurseForge),
    mc_versions:      vec![mc_version.clone()],
    loaders:          loaders.clone(),
    projects:         Vec::new(),
    lockfile_version: 1,
  };

  // Import projects from files list
  if let Some(files) = manifest["files"].as_array() {
    log::info!("Importing {} projects from modpack", files.len());

    // Create platform client
    use crate::platform::create_platform;
    let curseforge_token = std::env::var("CURSEFORGE_TOKEN").ok();
    let platform = create_platform("curseforge", curseforge_token)?;

    for file_entry in files {
      if let Some(project_id) = file_entry["projectID"].as_u64() {
        let project_id_str = project_id.to_string();
        log::info!("Fetching project: {project_id_str}");

        match platform
          .request_project_with_files(
            &project_id_str,
            &lockfile.mc_versions,
            &loaders.keys().cloned().collect::<Vec<_>>(),
          )
          .await
        {
          Ok(mut project) => {
            // Try to select the specific file if fileID is provided
            if let Some(file_id) = file_entry["fileID"].as_u64() {
              let file_id_str = file_id.to_string();
              // Try to find the file with matching ID
              if let Some(file) =
                project.files.iter().find(|f| f.id == file_id_str).cloned()
              {
                project.files = vec![file];
              } else {
                log::warn!(
                  "Could not find file {} for project {}, selecting best match",
                  file_id,
                  project.get_name()
                );
                if let Err(e) = project.select_file(
                  &lockfile.mc_versions,
                  &loaders.keys().cloned().collect::<Vec<_>>(),
                  None, // Use default (1 file) during import
                ) {
                  log::warn!(
                    "Failed to select file for {}: {}",
                    project.get_name(),
                    e
                  );
                  continue;
                }
              }
            } else {
              // No specific file ID, select best match
              if let Err(e) = project.select_file(
                &lockfile.mc_versions,
                &loaders.keys().cloned().collect::<Vec<_>>(),
                None, // Use default (1 file) during import
              ) {
                log::warn!(
                  "Failed to select file for {}: {}",
                  project.get_name(),
                  e
                );
                continue;
              }
            }
            lockfile.add_project(project);
          },
          Err(e) => {
            log::warn!("Failed to fetch project {project_id_str}: {e}");
          },
        }
      }
    }
  }

  // Create config
  let config = Config {
    name:                                  manifest["name"]
      .as_str()
      .unwrap_or("Imported Pack")
      .to_string(),
    version:                               manifest["version"]
      .as_str()
      .unwrap_or("1.0.0")
      .to_string(),
    description:                           None,
    author:                                manifest["author"]
      .as_str()
      .map(std::string::ToString::to_string),
    overrides:                             vec!["overrides".to_string()],
    server_overrides:                      None,
    client_overrides:                      None,
    paths:                                 Default::default(),
    projects:                              None,
    export_profiles:                       None,
    export_server_side_projects_to_client: None,
    file_count_preference:                 None,
  };

  // Save files using provided paths
  lockfile.save(lockfile_dir)?;
  config.save(config_dir)?;

  log::info!("Imported {} projects", lockfile.projects.len());

  // Extract overrides
  let overrides_prefix = manifest["overrides"].as_str().unwrap_or("overrides");

  for i in 0..archive.len() {
    let mut file = archive.by_index(i)?;
    let outpath = file.enclosed_name().ok_or_else(|| {
      PakkerError::InternalError("Invalid file path in archive".to_string())
    })?;

    if outpath.starts_with(overrides_prefix) {
      let target = outpath.strip_prefix(overrides_prefix).unwrap();

      if file.is_dir() {
        std::fs::create_dir_all(target)?;
      } else {
        if let Some(parent) = target.parent() {
          std::fs::create_dir_all(parent)?;
        }
        let mut outfile = File::create(target)?;
        std::io::copy(&mut file, &mut outfile)?;
      }
    }
  }

  Ok(())
}