#!/usr/bin/env bun

interface PR {
  number: number
  headRefName: string
  headRefOid: string
  createdAt: string
  isDraft: boolean
  title: string
}

async function main() {
  console.log("Fetching open contributor PRs...")

  const prsResult =
    await $`gh pr list --label contributor --state open --json number,headRefName,headRefOid,createdAt,isDraft,title --limit 100`.nothrow()
  if (prsResult.exitCode !== 0) {
    throw new Error(`Failed to fetch PRs: ${prsResult.stderr}`)
  }

  const allPRs: PR[] = JSON.parse(prsResult.stdout)
  const prs = allPRs.filter((pr) => !pr.isDraft)

  console.log(`Found ${prs.length} open non-draft contributor PRs`)

  console.log("Fetching latest dev branch...")
  const fetchDev = await $`git fetch origin dev`.nothrow()
  if (fetchDev.exitCode !== 0) {
    throw new Error(`Failed to fetch dev branch: ${fetchDev.stderr}`)
  }

  console.log("Checking out beta branch...")
  const checkoutBeta = await $`git checkout -B beta origin/dev`.nothrow()
  if (checkoutBeta.exitCode !== 0) {
    throw new Error(`Failed to checkout beta branch: ${checkoutBeta.stderr}`)
  }

  const applied: number[] = []
  const skipped: Array<{ number: number; reason: string }> = []

  for (const pr of prs) {
    console.log(`\nProcessing PR #${pr.number}: ${pr.title}`)

    // Try to update PR branch via GitHub API (rebase onto base branch)
    console.log(`  Attempting to rebase PR #${pr.number} via GitHub API...`)
    const updateBranch = await $`gh pr update-branch ${pr.number} --rebase`.nothrow()
    if (updateBranch.exitCode !== 0) {
      console.log(`  Rebase failed for PR #${pr.number} (has conflicts)`)
      console.log(`  Error: ${updateBranch.stderr}`)
      skipped.push({ number: pr.number, reason: "Rebase failed (conflicts)" })
      continue
    }

    console.log(`  Rebase initiated for PR #${pr.number}`)

    // Wait for rebase to complete by polling PR state
    console.log(`  Waiting for rebase to complete...`)
    let rebaseComplete = false
    let attempts = 0
    const maxAttempts = 30

    while (!rebaseComplete && attempts < maxAttempts) {
      await Bun.sleep(2000) // Wait 2 seconds
      attempts++

      const prCheck = await $`gh pr view ${pr.number} --json mergeStateStatus,headRefOid`.nothrow()
      if (prCheck.exitCode === 0) {
        const prData = JSON.parse(prCheck.stdout)
        // mergeStateStatus will be "clean" when rebase is complete and no conflicts
        if (prData.mergeStateStatus === "clean") {
          rebaseComplete = true
          console.log(`  Rebase completed for PR #${pr.number}`)
        }
      }
    }

    if (!rebaseComplete) {
      console.log(`  Timeout waiting for rebase on PR #${pr.number}`)
      skipped.push({ number: pr.number, reason: "Timeout waiting for rebase" })
      continue
    }

    // Fetch the rebased PR
    const fetchPR = await $`git fetch origin pull/${pr.number}/head:pr-${pr.number}`.nothrow()
    if (fetchPR.exitCode !== 0) {
      console.log(`  Failed to fetch PR #${pr.number} after rebase, skipping`)
      skipped.push({ number: pr.number, reason: "Failed to fetch after rebase" })
      continue
    }

    const merge = await $`git merge --squash pr-${pr.number}`.nothrow()
    if (merge.exitCode !== 0) {
      console.log(`  Squash merge failed for PR #${pr.number}`)
      console.log(`  Error: ${merge.stderr}`)
      await $`git reset --hard HEAD`.nothrow()
      skipped.push({ number: pr.number, reason: `Squash merge failed: ${merge.stderr}` })
      continue
    }

    const add = await $`git add -A`.nothrow()
    if (add.exitCode !== 0) {
      console.log(`  Failed to stage changes for PR #${pr.number}`)
      await $`git reset --hard HEAD`.nothrow()
      skipped.push({ number: pr.number, reason: "Failed to stage" })
      continue
    }

    const status = await $`git status --porcelain`.nothrow()
    if (status.exitCode !== 0 || !status.stdout.trim()) {
      console.log(`  No changes to commit for PR #${pr.number}, skipping`)
      await $`git reset --hard HEAD`.nothrow()
      skipped.push({ number: pr.number, reason: "No changes to commit" })
      continue
    }

    const commitMsg = `Apply PR #${pr.number}: ${pr.title}`
    const commit = await Bun.spawn(["git", "commit", "-m", commitMsg], { stdout: "pipe", stderr: "pipe" })
    const commitExit = await commit.exited
    const commitStderr = await Bun.readableStreamToText(commit.stderr)

    if (commitExit !== 0) {
      console.log(`  Failed to commit PR #${pr.number}`)
      console.log(`  Error: ${commitStderr}`)
      await $`git reset --hard HEAD`.nothrow()
      skipped.push({ number: pr.number, reason: `Commit failed: ${commitStderr}` })
      continue
    }

    console.log(`  Successfully applied PR #${pr.number}`)
    applied.push(pr.number)
  }

  console.log("\n--- Summary ---")
  console.log(`Applied: ${applied.length} PRs`)
  applied.forEach((num) => console.log(`  - PR #${num}`))
  console.log(`Skipped: ${skipped.length} PRs`)
  skipped.forEach((x) => console.log(`  - PR #${x.number}: ${x.reason}`))

  console.log("\nForce pushing beta branch...")
  const push = await $`git push origin beta --force`.nothrow()
  if (push.exitCode !== 0) {
    throw new Error(`Failed to push beta branch: ${push.stderr}`)
  }

  console.log("Successfully synced beta branch")
}

main().catch((err) => {
  console.error("Error:", err)
  process.exit(1)
})

function $(strings: TemplateStringsArray, ...values: unknown[]) {
  const cmd = strings.reduce((acc, str, i) => acc + str + (values[i] ?? ""), "")
  return {
    async nothrow() {
      const proc = Bun.spawn(cmd.split(" "), {
        stdout: "pipe",
        stderr: "pipe",
      })
      const exitCode = await proc.exited
      const stdout = await new Response(proc.stdout).text()
      const stderr = await new Response(proc.stderr).text()
      return { exitCode, stdout, stderr }
    },
  }
}