import { execFile } from 'node:child_process'
import { promisify } from 'node:util'
import fs from 'node:fs/promises'
import path from 'node:path'
import { config } from '../config.js'

const execFileAsync = promisify(execFile)

export async function fetchPreviewConfig(repoFullName, branch) {
  const [owner, repo] = repoFullName.split('/')
  if (!owner || !repo || !config.gitea.apiToken) {
    return null
  }

  const url = `${config.gitea.baseUrl}/api/v1/repos/${owner}/${repo}/contents/.webklar-preview.json?ref=${encodeURIComponent(branch)}`
  const response = await fetch(url, {
    headers: { Authorization: `token ${config.gitea.apiToken}` },
  })

  if (!response.ok) return null

  const data = await response.json()
  const content = Buffer.from(data.content || '', 'base64').toString('utf8')
  return JSON.parse(content)
}

export function defaultPreviewConfig(repoFullName) {
  const repoName = repoFullName.split('/').pop() || 'preview'
  return {
    enabled: false,
    type: 'static',
    branch: 'main',
    displayName: repoName,
    subdomain: repoName,
  }
}

async function cloneRepo(cloneUrl, targetDir, branch) {
  await fs.rm(targetDir, { recursive: true, force: true })
  await fs.mkdir(targetDir, { recursive: true })
  await execFileAsync('git', [
    'clone',
    '--depth',
    '1',
    '--branch',
    branch,
    cloneUrl,
    targetDir,
  ])
}

async function deployStatic(sourceDir, targetDir, indexSubdir = '') {
  const webroot = indexSubdir ? path.join(sourceDir, indexSubdir) : sourceDir
  await fs.rm(targetDir, { recursive: true, force: true })
  await fs.mkdir(targetDir, { recursive: true })
  await execFileAsync('cp', ['-R', `${webroot}/.`, targetDir])
}

async function deployNodeBuild(sourceDir, targetDir) {
  await execFileAsync('npm', ['ci'], { cwd: sourceDir })
  await execFileAsync('npm', ['run', 'build'], { cwd: sourceDir })
  const distDir = path.join(sourceDir, 'dist')
  await deployStatic(distDir, targetDir)
}

export function buildPreviewUrl(subdomain) {
  return `https://${subdomain}.${config.preview.baseHost}`
}

export async function runDeploy(repoFullName, branch, previewConfig) {
  if (!config.preview.deployRoot) {
    return { deployed: false, reason: 'PREVIEW_DEPLOY_ROOT nicht gesetzt' }
  }

  const subdomain = previewConfig.subdomain || repoFullName.split('/').pop()
  const cloneUrl = `${config.gitea.baseUrl}/${repoFullName}.git`
  const workDir = path.join(process.cwd(), 'preview-data', repoFullName.replace(/\//g, '_'))
  const targetDir = path.join(config.preview.deployRoot, subdomain)

  await cloneRepo(cloneUrl, workDir, branch)

  if (previewConfig.type === 'node_build') {
    await deployNodeBuild(workDir, targetDir)
  } else {
    await deployStatic(workDir, targetDir, previewConfig.index || '')
  }

  return { deployed: true, subdomain, targetDir }
}