import {getCurrentContext} from './context'

/**
 * File-based checkout using GitHub Contents API instead of git clone
 * Much faster, cheaper, and more reliable
 */

export interface FileInfo {
  path: string
  content: string
  sha: string
}

export class ApiCheckout {
  private octokit: any
  private owner: string
  private repo: string
  private commitSha: string
  private branchName?: string
  private cache: Map<string, FileInfo> = new Map()

  constructor(
    probotContext?: any,
    options?: {owner?: string; repo?: string; ref?: string; branch?: string}
  ) {
    // Use passed probotContext or get from async context
    const ctx = probotContext || getCurrentContext()
    if (!ctx && !options)
      throw new Error('No context available and no options provided')

    this.octokit = ctx?.probotContext?.octokit || ctx?.octokit
    this.owner = options?.owner || ctx?.repo?.owner
    this.repo = options?.repo || ctx?.repo?.repo

    // Primary source: options
    if (options?.ref) {
      this.commitSha = options.ref
    } else {
      // Fallback: pull_request payload
      const pullRequest =
        ctx?.probotContext?.payload?.pull_request || ctx?.payload?.pull_request
      if (pullRequest?.head?.sha) {
        this.commitSha = pullRequest.head.sha
      } else {
        throw new Error(
          'No commit SHA (ref) available for checkout. For issue_comment events, please provide ref in options.'
        )
      }
    }

    this.branchName =
      options?.branch ||
      ctx?.probotContext?.payload?.pull_request?.head?.ref ||
      ctx?.payload?.pull_request?.head?.ref
  }

  /**
   * Get file content via GitHub API
   */
  async getFile(path: string): Promise<FileInfo> {
    // Check cache first
    if (this.cache.has(path)) {
      return this.cache.get(path)!
    }

    try {
      const response = await this.octokit.repos.getContent({
        owner: this.owner,
        repo: this.repo,
        path: path,
        ref: this.commitSha
      })

      // Handle both file and directory responses
      if (Array.isArray(response.data)) {
        throw new Error(`Path ${path} is a directory, not a file`)
      }

      const content = Buffer.from(response.data.content, 'base64').toString(
        'utf-8'
      )
      const fileInfo: FileInfo = {
        path,
        content,
        sha: response.data.sha
      }

      // Cache the result
      this.cache.set(path, fileInfo)
      return fileInfo
    } catch (error) {
      throw new Error(`Failed to get file ${path}: ${error}`)
    }
  }

  /**
   * Update file content via GitHub API
   */
  async updateFile(
    path: string,
    newContent: string,
    message: string
  ): Promise<string> {
    const currentFile = await this.getFile(path)

    try {
      const response = await this.octokit.repos.createOrUpdateFileContents({
        owner: this.owner,
        repo: this.repo,
        path: path,
        message: message,
        content: Buffer.from(newContent).toString('base64'),
        sha: currentFile.sha,
        branch: this.branchName || this.commitSha
      })

      // Update cache
      const updatedFile: FileInfo = {
        path,
        content: newContent,
        sha: response.data.commit.sha
      }
      this.cache.set(path, updatedFile)

      return response.data.commit.sha
    } catch (error) {
      throw new Error(`Failed to update file ${path}: ${error}`)
    }
  }

  /**
   * Create a new file via GitHub API
   */
  async createFile(
    path: string,
    content: string,
    message: string
  ): Promise<string> {
    try {
      const response = await this.octokit.repos.createOrUpdateFileContents({
        owner: this.owner,
        repo: this.repo,
        path: path,
        message: message,
        content: Buffer.from(content).toString('base64'),
        branch: this.branchName || this.commitSha
      })

      // Update cache
      const newFile: FileInfo = {
        path,
        content,
        sha: response.data.commit.sha
      }
      this.cache.set(path, newFile)

      return response.data.commit.sha
    } catch (error) {
      throw new Error(`Failed to create file ${path}: ${error}`)
    }
  }

  /**
   * Get directory listing
   */
  async getDirectory(path: string): Promise<string[]> {
    try {
      const response = await this.octokit.repos.getContent({
        owner: this.owner,
        repo: this.repo,
        path: path,
        ref: this.commitSha
      })

      if (!Array.isArray(response.data)) {
        throw new Error(`Path ${path} is not a directory`)
      }

      return response.data
        .filter((item: any) => item.type === 'file')
        .map((item: any) => item.path)
    } catch (error) {
      throw new Error(`Failed to get directory ${path}: ${error}`)
    }
  }

  /**
   * Get repository tree structure
   */
  async getTree(): Promise<string[]> {
    try {
      const response = await this.octokit.git.getTree({
        owner: this.owner,
        repo: this.repo,
        tree_sha: this.commitSha,
        recursive: true
      })

      return response.data.tree
        .filter((item: any) => item.type === 'blob')
        .map((item: any) => item.path)
    } catch (error) {
      throw new Error(`Failed to get repository tree: ${error}`)
    }
  }
}