import * as fs from 'fs'
import * as path from 'path'
import { pathToFileURL } from 'url'

import Logger, { LoggerType } from '#application/logger'
import Storage from '#application/storage'
import { Command } from '#application/types'

export class CommandRegistry {
  private readonly commands: Map<string, Command> = new Map()
  private readonly logger = Logger.type(LoggerType.COMMAND)

  public getCommand(name: string): Command | undefined {
    return this.commands.get(name)
  }

  public async loadCommands(): Promise<void> {
    const directory = Storage.getAppPath('commands')
    this.logger.info(`Loading commands from: ${directory}`)

    try {
      const files = await fs.promises.readdir(directory, { withFileTypes: true })
      await Promise.all(files.filter((file) => this.isValidCommandFile(file)).map((file) => this.loadCommandFile(file)))
    } catch (error) {
      this.logger.error(`Failed to read commands directory: ${error instanceof Error ? error.message : String(error)}`)
    }
  }

  private isValidCommandFile(file: fs.Dirent): boolean {
    return file.isFile() && (file.name.endsWith('.ts') || file.name.endsWith('.js'))
  }

  private async loadCommandFile(file: fs.Dirent): Promise<void> {
    try {
      const filePath = Storage.getAppPath('commands', file.name)
      const commandName = path.basename(file.name, path.extname(file.name))

      const module = await import(pathToFileURL(filePath).href)
      if (typeof module.default !== 'function') {
        this.logger.warn(`Unrecognized export in ${file.name}`)
        return
      }

      this.registerCommand(commandName, module.default)
    } catch (error) {
      this.logger.error(`Error loading command ${file.name}: ${error instanceof Error ? error.message : String(error)}`)
    }
  }

  private registerCommand(name: string, CommandClass: Command): void {
    if (this.commands.has(name)) {
      this.logger.warn(`Command '${name}' is already registered. Overwriting...`)
    }
    this.commands.set(name, CommandClass)
    this.logger.info(`Registered command: ${name}`)
  }
}