// link <command> [args]
// Commands:
//   list
//   delete <alias>
//   clear
//   [package] <path|target>
//
// Examples:
//   cell link ../cell-steam             (Links package defined in ../cell-steam to that path)
//   cell link my-pkg ../cell-steam      (Links my-pkg to ../cell-steam)
//   cell link my-pkg other-pkg          (Links my-pkg to other-pkg)

var shop = use('shop')
var fd = use('fd')
var toml = use('toml')

if (args.length < 1) {
  log.console("Usage: link <command> [args] or link [package] <target>")
  log.console("Commands:")
  log.console("  list                 List all active links")
  log.console("  delete <alias>       Remove a link")
  log.console("  clear                Remove all links")
  log.console("  <path>               Link the package in <path> to <path>")
  log.console("  <alias> <target>     Link <alias> to <target> (path or package)")
  $_.stop()
  return
}

var cmd = args[0]

if (cmd == 'list') {
  var links = shop.load_links()
  var count = 0
  for (var k in links) {
    log.console(k + " -> " + links[k])
    count++
  }
  if (count == 0) log.console("No links.")
} else if (cmd == 'delete' || cmd == 'rm') {
  if (args.length < 2) {
    log.console("Usage: link delete <alias>")
    $_.stop()
    return
  }
  
  var target = args[1]
  
  // Try to remove directly
  if (shop.remove_link(target)) {
    // Update to restore original if possible
    log.console("Restoring " + target + "...")
    shop.update(target)
  } else {
    log.console("No link found for " + target)
  }
  
} else if (cmd == 'clear') {
  shop.clear_links()
  log.console("Links cleared. Run 'cell update' to restore packages if needed.")
} else {
  // Linking logic
  var pkg_name = null
  var target_path = null
  
  // Check for 'add' compatibility
  var start_idx = 0
  if (cmd == 'add') {
    start_idx = 1
  }
  
  // Parse arguments
  // usage: link [pkg] <target>
  // valid inputs:
  //   link ../foo
  //   link pkg ../foo
  //   link pkg remote-pkg
  
  var arg1 = args[start_idx]
  var arg2 = (args.length > start_idx + 1) ? args[start_idx + 1] : null
  
  if (!arg1) {
      log.console("Error: specific target or package required")
      $_.stop()
      return
  }

  if (arg2) {
      // Two arguments: explicit package name and target
      pkg_name = arg1
      target_path = arg2
  } else {
      // One argument: assume it's a path, and we need to infer the package name
      target_path = arg1
      
      // Resolve path to check for cell.toml
      var resolved = target_path
      if (fd.is_dir(resolved)) resolved = fd.realpath(resolved)
      
      var toml_path = resolved + '/cell.toml'
      if (!fd.is_file(toml_path)) {
          log.console("Error: No cell.toml found at " + resolved + ". Cannot infer package name.")
          log.console("If you meant to link an alias, provide the target: link <alias> <target>")
          $_.stop()
          return
      }
      
      // Read package name
      try {
          var content = toml.decode(text(fd.slurp(toml_path)))
          if (content.package) {
              pkg_name = content.package
              // If package name has version, strip it? 
              // Usually package = "name", version = "..." in cell.toml?
              // Or package = "name"
              // Standard is just name.
          } else {
              log.console("Error: cell.toml at " + resolved + " does not define a 'package' name.")
              $_.stop()
              return
          }
      } catch (e) {
          log.console("Error reading cell.toml: " + e)
          $_.stop()
          return
      }
      
      // Ensure target path is fully resolved since we inferred it
      if (fd.is_dir(target_path)) target_path = fd.realpath(target_path)
  }
  
  // Process the link
  
  // 1. Resolve target if it is a directory
  if (target_path != "." && fd.is_dir(target_path)) {
      target_path = fd.realpath(target_path)
  } else if (target_path == ".") {
       target_path = fd.realpath(target_path)
  } else if (target_path.startsWith('/') || target_path.startsWith('./') || target_path.startsWith('../')) {
       // It looks like a path but doesn't exist?
       log.console("Warning: Link target '" + target_path + "' does not exist locally. Linking as alias anyway.")
       if (target_path.startsWith('./') || target_path.startsWith('../')) {
           // Resolve relative path roughly?
            var cwd = fd.realpath('.')
            // simple concat (fd.realpath typically converts to abspath, but if file missing it might fail or return same)
            // Assuming user wants strict path if they used relative.
            // Using fd.realpath on CWD + path is safer if we want absolute.
            // But we don't have path manipulation lib easily exposed except implicit logic.
           // Leaving as provided string if not existing dir.
       }
  }

  // 2. Add link
  shop.add_link(pkg_name, target_path)
  
  // 3. Update shop
  // "Doing this effectively adds another item to the shop"
  // We trigger update to ensure the shop recognizes the new link
  shop.update(pkg_name)
}

$_.stop()