name: Chat Performance Comparison

on:
  workflow_dispatch:
    inputs:
      baseline_build:
        description: "Baseline version or commit SHA (e.g. \"1.116.0\", \"insiders\", \"abc1234\"). Default: config.jsonc baselineBuild."
        required: false
        type: string
      test_build:
        description: "Branch, PR ref, commit SHA, or version to test (e.g. \"my-feature\", \"refs/pull/12345/head\", \"1.115.0\"). Default: current pipeline branch (probably main)."
        required: false
        type: string
      runs:
        description: "Runs per scenario"
        required: false
        type: number
        default: 7
      scenarios:
        description: "Comma-separated scenario list. Default: all registered scenarios."
        required: false
        type: string
        default: ""
      threshold:
        description: "Regression threshold fraction (0.2 = 20%)"
        required: false
        type: number
        default: 0.2
      skip_leak_check:
        description: "Skip the memory leak check step"
        required: false
        type: boolean
        default: false
      test_settings:
        description: 'JSON object of VS Code settings for the test build (e.g. {"chat.experimental.smoothStreaming.enabled": true})'
        required: false
        type: string
        default: ""
      baseline_settings:
        description: 'JSON object of VS Code settings for the baseline build'
        required: false
        type: string
        default: ""
permissions:
  contents: read

concurrency:
  group: chat-perf-${{ github.run_id }}
  cancel-in-progress: true

env:
  # Only set when explicitly provided; otherwise scripts read config.jsonc
  BASELINE_BUILD_INPUT: ${{ inputs.baseline_build || '' }}
  TEST_BUILD_INPUT: ${{ inputs.test_build || '' }}
  PERF_RUNS: ${{ inputs.runs || '' }}
  PERF_THRESHOLD: ${{ inputs.threshold || '' }}
  SCENARIOS_INPUT: ${{ inputs.scenarios || '' }}
  TEST_SETTINGS_INPUT: ${{ inputs.test_settings || '' }}
  BASELINE_SETTINGS_INPUT: ${{ inputs.baseline_settings || '' }}
  # Skip binary downloads during `npm ci` (they hang intermittently on hosted
  # runners inside the nested postinstall installs). Electron and Playwright are
  # fetched explicitly later via `Download Electron` and `Install Playwright
  # Chromium`, which ignore these flags. Mirrors pr-node-modules.yml.
  ELECTRON_SKIP_BINARY_DOWNLOAD: 1
  PLAYWRIGHT_SKIP_BROWSER_DOWNLOAD: 1

jobs:
  # ── Shared setup: build once, cache everything ──────────────────────
  setup:
    name: Build & Cache
    runs-on: ubuntu-latest
    timeout-minutes: 50
    outputs:
      test_is_version: ${{ steps.resolve.outputs.is_version }}
      test_build_arg: ${{ steps.resolve.outputs.build_arg }}
      perf_matrix: ${{ steps.count_scenarios.outputs.matrix }}
    steps:
      - name: Resolve test build type
        id: resolve
        run: |
          INPUT="$TEST_BUILD_INPUT"
          if [[ -z "$INPUT" ]]; then
            echo "is_version=false" >> "$GITHUB_OUTPUT"
            echo "build_arg=" >> "$GITHUB_OUTPUT"
          elif [[ "$INPUT" =~ ^[0-9]+\.[0-9]+\.[0-9]+ ]] || [[ "$INPUT" == "insiders" ]] || [[ "$INPUT" == "stable" ]]; then
            echo "test_build is a version string: $INPUT (will download)"
            echo "is_version=true" >> "$GITHUB_OUTPUT"
            echo "build_arg=$INPUT" >> "$GITHUB_OUTPUT"
          else
            echo "test_build is a git ref: $INPUT (will checkout and build from source)"
            echo "is_version=false" >> "$GITHUB_OUTPUT"
            echo "build_arg=" >> "$GITHUB_OUTPUT"
          fi

      - name: Checkout
        uses: actions/checkout@v6
        with:
          ref: ${{ steps.resolve.outputs.is_version != 'true' && inputs.test_build || github.ref }}

      - name: Setup Node.js
        uses: actions/setup-node@v6
        with:
          node-version-file: .nvmrc
          cache: npm

      - name: Install system dependencies
        run: |
          sudo apt update -y
          sudo apt install -y \
            build-essential pkg-config \
            libx11-dev libx11-xcb-dev libxkbfile-dev \
            libnotify-bin libkrb5-dev \
            xvfb sqlite3 \
            libnss3 libatk1.0-0 libatk-bridge2.0-0 \
            libcups2t64 libdrm2 libxcomposite1 libxdamage1 \
            libxrandr2 libgbm1 libpango-1.0-0 libcairo2 \
            libasound2t64 libxshmfence1 libgtk-3-0

      - name: Install dependencies
        run: |
          set -e
          # Retry with a per-attempt timeout to survive transient npm registry
          # hangs/failures on hosted runners (mirrors pr-node-modules.yml).
          for i in {1..5}; do
            timeout 900 npm ci && break
            if [ $i -eq 5 ]; then
              echo "npm ci failed/hung too many times" >&2
              exit 1
            fi
            echo "npm ci attempt $i failed or timed out, retrying..."
          done
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

      - name: Install build dependencies
        working-directory: build
        run: |
          set -e
          for i in {1..5}; do
            timeout 900 npm ci && break
            if [ $i -eq 5 ]; then
              echo "npm ci failed/hung too many times" >&2
              exit 1
            fi
            echo "npm ci attempt $i failed or timed out, retrying..."
          done

      - name: Transpile source
        run: npm run transpile-client

      - name: Build copilot extension
        run: npm run compile
        working-directory: extensions/copilot

      - name: Download Electron
        run: node build/lib/preLaunch.ts

      - name: Cache Electron
        uses: actions/cache/save@v5
        with:
          path: ~/.cache/electron
          key: electron-${{ runner.os }}-${{ hashFiles('.nvmrc', 'package.json') }}

      - name: Install Playwright Chromium
        run: npx playwright install chromium

      - name: Cache Playwright
        uses: actions/cache/save@v5
        with:
          path: ~/.cache/ms-playwright
          key: playwright-${{ runner.os }}-${{ hashFiles('package.json') }}

      - name: Compute perf matrix
        id: count_scenarios
        run: |
          node -e "
            require('./scripts/chat-simulation/common/perf-scenarios').registerPerfScenarios();
            const { getScenarioIds } = require('./scripts/chat-simulation/common/mock-llm-server.ts');
            const userInput = process.env.SCENARIOS_INPUT || '';
            const parsed = userInput.split(',').map(s => s.trim()).filter(Boolean);
            const allScens = parsed.length > 0 ? parsed : getScenarioIds();
            if (allScens.length === 0) {
              console.error('No scenarios found. Provide a non-empty scenarios input or ensure getScenarioIds() returns at least one scenario.');
              process.exit(1);
            }
            const maxGroups = 4;
            const needed = Math.min(allScens.length, maxGroups);
            const groups = Array.from({ length: needed }, (_, i) => i + 1);
            const fs = require('fs');
            const matrix = JSON.stringify({ group: groups });
            fs.appendFileSync(process.env.GITHUB_OUTPUT, 'matrix=' + matrix + '\\n');
            console.log('Total scenarios: ' + allScens.length + ', groups: ' + needed);
          "

      - name: Upload build output
        uses: actions/upload-artifact@v7
        with:
          name: build-output
          path: |
            out/
            extensions/copilot/dist/
          retention-days: 1

  # ── Perf comparison (split across matrix groups) ─────────────────────
  chat-perf:
    name: Chat Perf (${{ matrix.group }})
    needs: setup
    runs-on: ubuntu-latest
    timeout-minutes: 60
    strategy:
      fail-fast: false
      matrix: ${{ fromJSON(needs.setup.outputs.perf_matrix) }}
    steps:
      - name: Checkout
        uses: actions/checkout@v6
        with:
          ref: ${{ needs.setup.outputs.test_is_version != 'true' && inputs.test_build || github.ref }}

      - name: Setup Node.js
        uses: actions/setup-node@v6
        with:
          node-version-file: .nvmrc
          cache: npm

      - name: Install system dependencies
        run: |
          sudo apt update -y
          sudo apt install -y \
            build-essential pkg-config \
            libx11-dev libx11-xcb-dev libxkbfile-dev \
            libnotify-bin libkrb5-dev \
            xvfb sqlite3 \
            libnss3 libatk1.0-0 libatk-bridge2.0-0 \
            libcups2t64 libdrm2 libxcomposite1 libxdamage1 \
            libxrandr2 libgbm1 libpango-1.0-0 libcairo2 \
            libasound2t64 libxshmfence1 libgtk-3-0

      - name: Install dependencies
        run: |
          set -e
          for i in {1..5}; do
            timeout 900 npm ci && break
            if [ $i -eq 5 ]; then
              echo "npm ci failed/hung too many times" >&2
              exit 1
            fi
            echo "npm ci attempt $i failed or timed out, retrying..."
          done
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

      - name: Download build output
        uses: actions/download-artifact@v8
        with:
          name: build-output

      - name: Restore Electron cache
        uses: actions/cache/restore@v5
        with:
          path: ~/.cache/electron
          key: electron-${{ runner.os }}-${{ hashFiles('.nvmrc', 'package.json') }}

      - name: Download Electron
        run: node build/lib/preLaunch.ts

      - name: Restore Playwright cache
        uses: actions/cache/restore@v5
        with:
          path: ~/.cache/ms-playwright
          key: playwright-${{ runner.os }}-${{ hashFiles('package.json') }}

      - name: Install Playwright Chromium
        run: npx playwright install chromium

      - name: Resolve scenario group
        id: scenarios
        run: |
          node -e "
            const fs = require('fs');
            require('./scripts/chat-simulation/common/perf-scenarios').registerPerfScenarios();
            const { getScenarioIds } = require('./scripts/chat-simulation/common/mock-llm-server.ts');
            const userInput = process.env.SCENARIOS_INPUT || '';
            const parsed = userInput.split(',').map(s => s.trim()).filter(Boolean);
            const allScens = parsed.length > 0 ? parsed : getScenarioIds();
            const groups = parseInt(process.env.TOTAL_GROUPS, 10);
            const group = parseInt(process.env.MATRIX_GROUP, 10);
            // Distribute scenarios round-robin across groups
            const groupScens = allScens.filter((_, i) => (i % groups) + 1 === group);
            if (groupScens.length === 0) {
              console.log('No scenarios for group ' + group);
              fs.appendFileSync(process.env.GITHUB_OUTPUT, 'skip=true\n');
            } else {
              const args = groupScens.map(s => '--scenario ' + s).join(' ');
              fs.appendFileSync(process.env.GITHUB_OUTPUT, 'skip=false\n');
              fs.appendFileSync(process.env.GITHUB_OUTPUT, 'args=' + args + '\n');
              console.log('Group ' + group + ' (' + groupScens.length + '/' + allScens.length + '): ' + groupScens.join(', '));
            }
          "
        env:
          MATRIX_GROUP: ${{ matrix.group }}
          TOTAL_GROUPS: ${{ strategy.job-total }}

      - name: Run chat perf comparison
        id: perf
        if: steps.scenarios.outputs.skip != 'true'
        env:
          SCENARIO_ARGS: ${{ steps.scenarios.outputs.args }}
        run: |
          PERF_ARGS=("--ci")
          if [[ -n "$BASELINE_BUILD_INPUT" ]]; then
            PERF_ARGS+=("--baseline-build" "$BASELINE_BUILD_INPUT")
          fi
          TEST_BUILD_ARG="${{ needs.setup.outputs.test_build_arg }}"
          if [[ -n "$TEST_BUILD_ARG" ]]; then
            PERF_ARGS+=("--build" "$TEST_BUILD_ARG")
          fi
          if [[ -n "$PERF_RUNS" ]]; then
            PERF_ARGS+=("--runs" "$PERF_RUNS")
          fi
          if [[ -n "$PERF_THRESHOLD" ]]; then
            PERF_ARGS+=("--threshold" "$PERF_THRESHOLD")
          fi
          PERF_ARGS+=("--production-build")

          # Convert JSON settings objects to --test-setting / --baseline-setting flags
          if [[ -n "$TEST_SETTINGS_INPUT" ]]; then
            while IFS='=' read -r key value; do
              PERF_ARGS+=("--test-setting" "$key=$value")
            done < <(node -e "const s=JSON.parse(process.env.TEST_SETTINGS_INPUT); for (const [k,v] of Object.entries(s)) console.log(k+'='+v)")
          fi
          if [[ -n "$BASELINE_SETTINGS_INPUT" ]]; then
            while IFS='=' read -r key value; do
              PERF_ARGS+=("--baseline-setting" "$key=$value")
            done < <(node -e "const s=JSON.parse(process.env.BASELINE_SETTINGS_INPUT); for (const [k,v] of Object.entries(s)) console.log(k+'='+v)")
          fi

          # Split SCENARIO_ARGS on whitespace into array elements
          read -ra SCENARIO_ARR <<< "$SCENARIO_ARGS"

          set +eo pipefail
          xvfb-run node scripts/chat-simulation/test-chat-perf-regression.js \
            "${PERF_ARGS[@]}" \
            "${SCENARIO_ARR[@]}" \
            2>&1 | tee perf-output.log
          echo "exit_code=${PIPESTATUS[0]}" >> "$GITHUB_OUTPUT"

      - name: Clean up temporary build artifacts
        if: always() && steps.scenarios.outputs.skip != 'true'
        run: |
          # Clean up tmp dirs used by VS Code instances
          rm -rf /tmp/vscode-chat-simulation 2>/dev/null || true
          # Remove the production build to free space for artifact upload
          rm -rf ../VSCode-* 2>/dev/null || true
          echo "Disk usage after cleanup:"
          df -h . | tail -1

      - name: Upload perf results
        if: always() && steps.scenarios.outputs.skip != 'true'
        uses: actions/upload-artifact@v7
        with:
          name: perf-results-${{ matrix.group }}
          include-hidden-files: true
          path: |
            perf-output.log
            .chat-simulation-data/
          retention-days: 30

      - name: Upload perf summary data
        if: always() && steps.scenarios.outputs.skip != 'true'
        uses: actions/upload-artifact@v7
        with:
          name: perf-summary-${{ matrix.group }}
          include-hidden-files: true
          path: |
            perf-output.log
            .chat-simulation-data/**/results.json
            .chat-simulation-data/**/baseline-*.json
            .chat-simulation-data/ci-summary.md
          retention-days: 1

      - name: Check for regressions
        if: always() && steps.perf.outputs.exit_code != '' &&
          steps.perf.outputs.exit_code != '0'
        run: |
          echo "::error::Chat perf regression detected (exit code ${{ steps.perf.outputs.exit_code }}). See perf-output.log for details."
          exit 1

  # ── Memory leak check (runs in parallel with perf) ──────────────────
  leak-check:
    name: Leak Check
    needs: setup
    if: inputs.skip_leak_check != true
    runs-on: ubuntu-latest
    timeout-minutes: 60
    steps:
      - name: Checkout
        uses: actions/checkout@v6
        with:
          ref: ${{ needs.setup.outputs.test_is_version != 'true' && inputs.test_build || github.ref }}

      - name: Setup Node.js
        uses: actions/setup-node@v6
        with:
          node-version-file: .nvmrc
          cache: npm

      - name: Install system dependencies
        run: |
          sudo apt update -y
          sudo apt install -y \
            build-essential pkg-config \
            libx11-dev libx11-xcb-dev libxkbfile-dev \
            libnotify-bin libkrb5-dev \
            xvfb \
            libnss3 libatk1.0-0 libatk-bridge2.0-0 \
            libcups2t64 libdrm2 libxcomposite1 libxdamage1 \
            libxrandr2 libgbm1 libpango-1.0-0 libcairo2 \
            libasound2t64 libxshmfence1 libgtk-3-0

      - name: Install dependencies
        run: |
          set -e
          for i in {1..5}; do
            timeout 900 npm ci && break
            if [ $i -eq 5 ]; then
              echo "npm ci failed/hung too many times" >&2
              exit 1
            fi
            echo "npm ci attempt $i failed or timed out, retrying..."
          done
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

      - name: Download build output
        uses: actions/download-artifact@v8
        with:
          name: build-output

      - name: Restore Electron cache
        uses: actions/cache/restore@v5
        with:
          path: ~/.cache/electron
          key: electron-${{ runner.os }}-${{ hashFiles('.nvmrc', 'package.json') }}

      - name: Download Electron
        run: node build/lib/preLaunch.ts

      - name: Restore Playwright cache
        uses: actions/cache/restore@v5
        with:
          path: ~/.cache/ms-playwright
          key: playwright-${{ runner.os }}-${{ hashFiles('package.json') }}

      - name: Install Playwright Chromium
        run: npx playwright install chromium

      - name: Run memory leak check
        id: leak
        run: |
          LEAK_ARGS="--verbose --ci"
          TEST_BUILD_ARG="${{ needs.setup.outputs.test_build_arg }}"
          if [[ -n "$TEST_BUILD_ARG" ]]; then
            LEAK_ARGS="$LEAK_ARGS --build $TEST_BUILD_ARG"
          fi

          set +eo pipefail
          xvfb-run node scripts/chat-simulation/test-chat-mem-leaks.js \
            $LEAK_ARGS \
            2>&1 | tee leak-output.log
          echo "exit_code=${PIPESTATUS[0]}" >> "$GITHUB_OUTPUT"

      - name: Clean up temporary files
        if: always()
        run: |
          rm -rf /tmp/vscode-chat-simulation 2>/dev/null || true

      - name: Upload leak results
        if: always()
        uses: actions/upload-artifact@v7
        with:
          name: leak-results
          include-hidden-files: true
          path: |
            leak-output.log
            .chat-simulation-data/chat-simulation-leak-results.json
            .chat-simulation-data/ci-summary-leak.md
          retention-days: 30

      - name: Check for leaks
        if: always() && steps.leak.outputs.exit_code != '' &&
          steps.leak.outputs.exit_code != '0'
        run: |
          echo "::error::Chat memory leak detected (exit code ${{ steps.leak.outputs.exit_code }}). See leak-output.log for details."
          exit 1

  # ── Report: collect results, write summary, fail on regression ──────
  report:
    name: Report
    needs: [ setup, chat-perf, leak-check ]
    if: always()
    runs-on: ubuntu-latest
    timeout-minutes: 30
    steps:
      - name: Checkout
        uses: actions/checkout@v6
        with:
          ref: ${{ needs.setup.outputs.test_is_version != 'true' && inputs.test_build || github.ref }}

      - name: Setup Node.js
        uses: actions/setup-node@v6
        with:
          node-version-file: .nvmrc

      - name: Download perf summary data
        uses: actions/download-artifact@v8
        with:
          pattern: perf-summary-*
          path: perf-results

      - name: Download leak results
        if: inputs.skip_leak_check != true && needs.leak-check.result != 'skipped'
        uses: actions/download-artifact@v8
        with:
          name: leak-results
          path: leak-results
        continue-on-error: true

      - name: Generate unified summary
        env:
          TEST_COMMIT: ${{ needs.setup.outputs.test_build_arg || github.sha }}
        run: |
          LEAK_ARG=""
          if [[ -f leak-results/.chat-simulation-data/ci-summary-leak.md ]]; then
            LEAK_ARG="--leak-summary leak-results/.chat-simulation-data/ci-summary-leak.md"
          fi

          node scripts/chat-simulation/merge-ci-summary.js \
            --results-dir perf-results \
            --output ci-summary.md \
            $LEAK_ARG

          cat ci-summary.md >> "$GITHUB_STEP_SUMMARY"

      - name: Upload CI summary
        if: always()
        uses: actions/upload-artifact@v7
        with:
          name: chat-perf-summary
          path: ci-summary.md
          retention-days: 30

      - name: Fail on regression
        id: regression
        if: needs.chat-perf.result == 'failure' || (inputs.skip_leak_check != true &&
          needs.leak-check.result == 'failure')
        run: |
          if [[ "${{ needs.chat-perf.result }}" == "failure" ]]; then
            echo "::error::Chat performance regression detected. See job summary for details."
          fi
          if [[ "${{ inputs.skip_leak_check }}" != "true" && "${{ needs.leak-check.result }}" == "failure" ]]; then
            echo "::error::Chat memory leak detected. See leak-output.log for details."
          fi
          exit 1