name: Nix Build

on:
  pull_request:
    branches:
      - main
  push:
    branches:
      - main

permissions:
  contents: read
  pull-requests: write

jobs:
  check-workspace-sync:
    name: Check flake.nix workspace sync
    runs-on: ubuntu-latest

    steps:
      - name: Checkout
        uses: actions/checkout@v6

      - name: Check workspace sync
        id: check
        run: |
          set -euo pipefail
          if node scripts/check-nix-workspace.mjs; then
            echo "SYNC_OK=true" >> "$GITHUB_OUTPUT"
          else
            echo "SYNC_OK=false" >> "$GITHUB_OUTPUT"
          fi

      - name: Extract missing items
        if: steps.check.outputs.SYNC_OK == 'false' && github.event_name == 'pull_request'
        id: missing
        run: |
          {
            echo "body<<EOF"
            echo "<!-- nix-workspace-sync-bot -->"
            echo "❌ flake.nix workspace lists out of sync"
            echo ""
            echo "The recursive workspace dependencies of \`apps/kimi-code\` do not match \`flake.nix\`. Please run \`node scripts/check-nix-workspace.mjs\` locally for details."
            echo ""
            echo "Typical fix: add the missing package name to \`workspaceNames\` and its path to \`workspacePaths\` in \`flake.nix\`."
            echo "EOF"
          } >> "$GITHUB_OUTPUT"

      - name: Post or update PR comment
        if: steps.check.outputs.SYNC_OK == 'false' && github.event_name == 'pull_request'
        uses: actions/github-script@v7
        env:
          COMMENT_BODY: ${{ steps.missing.outputs.body }}
        with:
          script: |
            const marker = '<!-- nix-workspace-sync-bot -->';
            const body = process.env.COMMENT_BODY;

            const { data: comments } = await github.rest.issues.listComments({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: context.issue.number,
            });

            const existing = comments.find(c =>
              c.user.login === 'github-actions[bot]' && c.body.includes(marker)
            );

            if (existing) {
              await github.rest.issues.updateComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                comment_id: existing.id,
                body,
              });
            } else {
              await github.rest.issues.createComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: context.issue.number,
                body,
              });
            }

      - name: Fail if workspace sync failed
        if: steps.check.outputs.SYNC_OK == 'false'
        run: exit 1

  nix-build:
    name: nix build .#kimi-code
    needs: check-workspace-sync
    runs-on: ubuntu-latest

    steps:
      - name: Checkout
        uses: actions/checkout@v6

      - name: Install Nix
        uses: cachix/install-nix-action@v31
        with:
          nix-path: nixpkgs=channel:nixos-unstable

      - name: Build
        id: build
        run: |
          set -euo pipefail
          LOG_FILE="$(mktemp)"
          if nix build .#kimi-code --print-build-logs 2>&1 | tee "$LOG_FILE"; then
            echo "BUILD_FAILED=false" >> "$GITHUB_OUTPUT"
          else
            echo "BUILD_FAILED=true" >> "$GITHUB_OUTPUT"
            echo "LOG_FILE=$LOG_FILE" >> "$GITHUB_OUTPUT"
          fi

      - name: Extract error log
        if: steps.build.outputs.BUILD_FAILED == 'true' && github.event_name == 'pull_request'
        id: error
        run: |
          LOG_FILE="${{ steps.build.outputs.LOG_FILE }}"

          # Extract hash mismatch info
          SPECIFIED=$(grep -oP 'specified:\s+\K\S+' "$LOG_FILE" || true)
          GOT=$(grep -oP 'got:\s+\K\S+' "$LOG_FILE" || true)

          if [ -n "$SPECIFIED" ] && [ -n "$GOT" ]; then
            {
              echo "body<<EOF"
              echo "❌ Nix build failed"
              echo ""
              echo "Hash mismatch in \`pnpmDeps\`:"
              echo "| | Hash |"
              echo "|---|---|"
              echo "| **specified** | \`$SPECIFIED\` |"
              echo "| **got** | \`$GOT\` |"
              echo ""
              echo "Please update \`flake.nix\` with the **got** hash."
              echo "EOF"
            } >> "$GITHUB_OUTPUT"
          else
            TAIL=$(tail -n 80 "$LOG_FILE" | sed 's/^/    /')
            {
              echo "body<<EOF"
              echo "❌ Nix build failed"
              echo ""
              echo "\`\`\`"
              echo "$TAIL"
              echo "\`\`\`"
              echo "EOF"
            } >> "$GITHUB_OUTPUT"
          fi

      - name: Post or update PR comment
        if: steps.build.outputs.BUILD_FAILED == 'true' && github.event_name == 'pull_request'
        uses: actions/github-script@v7
        env:
          COMMENT_BODY: ${{ steps.error.outputs.body }}
        with:
          script: |
            const marker = '<!-- nix-build-bot -->';
            const body = marker + '\n' + process.env.COMMENT_BODY;

            const { data: comments } = await github.rest.issues.listComments({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: context.issue.number,
            });

            const existing = comments.find(c =>
              c.user.login === 'github-actions[bot]' && c.body.includes(marker)
            );

            if (existing) {
              await github.rest.issues.updateComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                comment_id: existing.id,
                body,
              });
            } else {
              await github.rest.issues.createComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: context.issue.number,
                body,
              });
            }

      - name: Fail the job if build failed
        if: steps.build.outputs.BUILD_FAILED == 'true'
        run: exit 1