use std::{collections::HashMap, path::Path};

use crate::{
  cli::InitArgs,
  error::PakkerError,
  model::{Config, LockFile, ResolvedCredentials, Target},
  ui_utils::{
    prompt_curseforge_api_key,
    prompt_input,
    prompt_select,
    prompt_yes_no,
  },
};

pub fn execute(
  args: InitArgs,
  global_yes: bool,
  lockfile_path: &Path,
  config_path: &Path,
) -> Result<(), PakkerError> {
  let skip_prompts = global_yes;

  if lockfile_path.exists() {
    return Err(PakkerError::AlreadyExists(
      "Lock file already exists".into(),
    ));
  }

  // Interactive mode: prompt for values not provided via CLI and --yes not set
  let is_interactive = !skip_prompts && args.name.is_none();

  // Get modpack name
  let name = if let Some(name) = args.name.clone() {
    name
  } else if is_interactive {
    prompt_input("Modpack name", Some("My Modpack"))
      .map_err(|e| PakkerError::InvalidInput(e.to_string()))?
  } else {
    "My Modpack".to_string()
  };

  // Get modpack version
  let version = if let Some(version) = args.version.clone() {
    version
  } else if is_interactive {
    prompt_input("Version", Some("1.0.0"))
      .map_err(|e| PakkerError::InvalidInput(e.to_string()))?
  } else {
    "1.0.0".to_string()
  };

  // Get target platform
  let target = if let Some(target) = args.target.clone() {
    target
  } else if is_interactive {
    let targets = ["multiplatform", "curseforge", "modrinth"];
    let idx = prompt_select("Target platform", &targets)
      .map_err(|e| PakkerError::InvalidInput(e.to_string()))?;
    targets[idx].to_string()
  } else {
    "multiplatform".to_string()
  };

  let target_enum = match target.as_str() {
    "curseforge" => Target::CurseForge,
    "modrinth" => Target::Modrinth,
    "multiplatform" => Target::Multiplatform,
    _ => {
      return Err(PakkerError::InvalidInput(format!(
        "Invalid target: {target}"
      )));
    },
  };

  // Get Minecraft versions (supports multiple)
  let mc_versions = if let Some(versions) = args.mc_versions.clone() {
    versions
  } else if is_interactive {
    let input =
      prompt_input("Minecraft versions (space-separated)", Some("1.20.1"))
        .map_err(|e| PakkerError::InvalidInput(e.to_string()))?;
    input.split_whitespace().map(String::from).collect()
  } else {
    vec!["1.20.1".to_string()]
  };

  // Get mod loaders (supports multiple in name=version format)
  let loaders: HashMap<String, String> = if let Some(loader_strs) = args.loaders
  {
    let mut map = HashMap::new();
    for loader_str in loader_strs {
      let parts: Vec<&str> = loader_str.splitn(2, '=').collect();
      if parts.len() == 2 {
        map.insert(parts[0].to_string(), parts[1].to_string());
      } else {
        // If no version specified, use "latest"
        map.insert(loader_str, "latest".to_string());
      }
    }
    map
  } else if is_interactive {
    let loader_options = ["fabric", "forge", "neoforge", "quilt"];
    let idx = prompt_select("Mod loader", &loader_options)
      .map_err(|e| PakkerError::InvalidInput(e.to_string()))?;
    let loader = loader_options[idx].to_string();

    let loader_version = prompt_input("Loader version", Some("latest"))
      .map_err(|e| PakkerError::InvalidInput(e.to_string()))?;

    let mut map = HashMap::new();
    map.insert(loader, loader_version);
    map
  } else {
    let mut map = HashMap::new();
    map.insert("fabric".to_string(), "latest".to_string());
    map
  };

  let lockfile = LockFile {
    target: Some(target_enum),
    mc_versions,
    loaders,
    projects: Vec::new(),
    lockfile_version: 2,
  };

  // Save expects directory path, so get parent directory
  let lockfile_dir = lockfile_path.parent().unwrap_or_else(|| Path::new("."));
  lockfile.save(lockfile_dir)?;

  let config = Config {
    name:                                  name.clone(),
    version:                               version.clone(),
    description:                           None,
    author:                                None,
    overrides:                             vec!["overrides".to_string()],
    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,
  };

  let config_dir = config_path.parent().unwrap_or_else(|| Path::new("."));
  config.save(config_dir)?;

  println!("Initialized new modpack '{name}' v{version}");
  println!("  Target: {target}");
  println!("  Minecraft: {}", lockfile.mc_versions.join(", "));
  println!(
    "  Loaders: {}",
    lockfile
      .loaders
      .iter()
      .map(|(k, v)| format!("{k}={v}"))
      .collect::<Vec<_>>()
      .join(", ")
  );

  // Check if CurseForge API key is needed and prompt if interactive
  if is_interactive && (target == "curseforge" || target == "multiplatform") {
    let credentials = ResolvedCredentials::load();
    let has_cf_key = credentials.curseforge_api_key().is_some();

    if !has_cf_key {
      println!();
      if prompt_yes_no(
        "Would you like to set up CurseForge API key now?",
        true,
        skip_prompts,
      )
      .map_err(|e| PakkerError::InvalidInput(e.to_string()))?
        && let Ok(Some(api_key)) = prompt_curseforge_api_key(skip_prompts)
      {
        // Save to credentials file
        let creds_path = std::env::var("HOME").map_or_else(
          |_| Path::new(".pakku").to_path_buf(),
          |h| Path::new(&h).join(".pakku"),
        );

        std::fs::create_dir_all(&creds_path).ok();

        let creds_file = creds_path.join("credentials");
        let content =
          format!("# Pakku/Pakker credentials\nCURSEFORGE_API_KEY={api_key}\n");
        if std::fs::write(&creds_file, content).is_ok() {
          println!("CurseForge API key saved to ~/.pakku/credentials");
        }
      }
    }
  }

  Ok(())
}