name: Skill Validator — PR Gate

on:
  pull_request:
    branches: [main]
    types: [opened, synchronize, reopened]
    paths:
      - "skills/**"
      - "agents/**"
      - "plugins/**/skills/**"
      - "plugins/**/agents/**"

permissions:
  contents: read

jobs:
  skill-check:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
        with:
          fetch-depth: 0

      # ── Download & cache skill-validator ──────────────────────────
      - name: Get cache key date
        id: cache-date
        run: echo "date=$(date +%Y-%m-%d)" >> "$GITHUB_OUTPUT"

      - name: Restore skill-validator from cache
        id: cache-sv
        uses: actions/cache/restore@cdf6c1fa76f9f475f3d7449005a359c84ca0f306 # v5.0.3
        with:
          path: .skill-validator
          key: skill-validator-linux-x64-${{ steps.cache-date.outputs.date }}
          restore-keys: |
            skill-validator-linux-x64-

      - name: Download skill-validator
        if: steps.cache-sv.outputs.cache-hit != 'true'
        run: |
          mkdir -p .skill-validator
          curl -fsSL \
            "https://github.com/dotnet/skills/releases/download/skill-validator-nightly/skill-validator-linux-x64.tar.gz" \
            -o .skill-validator/skill-validator-linux-x64.tar.gz
          tar -xzf .skill-validator/skill-validator-linux-x64.tar.gz -C .skill-validator
          rm .skill-validator/skill-validator-linux-x64.tar.gz
          chmod +x .skill-validator/skill-validator

      - name: Save skill-validator to cache
        if: steps.cache-sv.outputs.cache-hit != 'true'
        uses: actions/cache/save@cdf6c1fa76f9f475f3d7449005a359c84ca0f306 # v5.0.3
        with:
          path: .skill-validator
          key: skill-validator-linux-x64-${{ steps.cache-date.outputs.date }}

      # ── Detect changed skills & agents ────────────────────────────
      - name: Detect changed skills and agents
        id: detect
        run: |
          declare -A SEEN_SKILL_DIRS=()
          declare -A SEEN_AGENT_FILES=()
          SKILL_DIRS=()
          AGENT_FILES=()

          while IFS= read -r -d '' file; do
            case "$file" in
              skills/*)
                skill_dir="${file#skills/}"
                skill_dir="skills/${skill_dir%%/*}"
                if [ -d "$skill_dir" ] && [ -z "${SEEN_SKILL_DIRS[$skill_dir]+x}" ]; then
                  SEEN_SKILL_DIRS["$skill_dir"]=1
                  SKILL_DIRS+=("$skill_dir")
                fi
                ;;
              plugins/*/skills/*)
                IFS='/' read -r seg1 seg2 seg3 seg4 _ <<< "$file"
                skill_dir="$seg1/$seg2/$seg3/$seg4"
                if [ -d "$skill_dir" ] && [ -z "${SEEN_SKILL_DIRS[$skill_dir]+x}" ]; then
                  SEEN_SKILL_DIRS["$skill_dir"]=1
                  SKILL_DIRS+=("$skill_dir")
                fi
                ;;
            esac

            case "$file" in
              agents/*.agent.md|plugins/*/agents/*.agent.md)
                if [ -f "$file" ] && [ -z "${SEEN_AGENT_FILES[$file]+x}" ]; then
                  SEEN_AGENT_FILES["$file"]=1
                  AGENT_FILES+=("$file")
                fi
                ;;
            esac
          done < <(git diff --name-only -z "origin/${{ github.base_ref }}...HEAD")

          SKILL_COUNT=${#SKILL_DIRS[@]}
          AGENT_COUNT=${#AGENT_FILES[@]}
          TOTAL=$((SKILL_COUNT + AGENT_COUNT))

          {
            echo "total=$TOTAL"
            echo "skill_count=$SKILL_COUNT"
            echo "agent_count=$AGENT_COUNT"
            echo "skill_dirs<<EOF"
            printf '%s\n' "${SKILL_DIRS[@]}"
            echo "EOF"
            echo "agent_files<<EOF"
            printf '%s\n' "${AGENT_FILES[@]}"
            echo "EOF"
          } >> "$GITHUB_OUTPUT"

          echo "Found $SKILL_COUNT skill dir(s) and $AGENT_COUNT agent file(s) to check."

      # ── Run skill-validator check ─────────────────────────────────
      - name: Run skill-validator check
        id: check
        if: steps.detect.outputs.total != '0'
        env:
          SKILL_DIRS_RAW: ${{ steps.detect.outputs.skill_dirs }}
          AGENT_FILES_RAW: ${{ steps.detect.outputs.agent_files }}
        run: |
          SKILL_DIRS=()
          AGENT_FILES=()

          if [ -n "$SKILL_DIRS_RAW" ]; then
            while IFS= read -r dir; do
              [ -n "$dir" ] && SKILL_DIRS+=("$dir")
            done <<< "$SKILL_DIRS_RAW"
          fi

          if [ -n "$AGENT_FILES_RAW" ]; then
            while IFS= read -r file; do
              [ -n "$file" ] && AGENT_FILES+=("$file")
            done <<< "$AGENT_FILES_RAW"
          fi

          CMD=(.skill-validator/skill-validator check --verbose)

          if [ ${#SKILL_DIRS[@]} -gt 0 ]; then
            CMD+=(--skills "${SKILL_DIRS[@]}")
          fi

          if [ ${#AGENT_FILES[@]} -gt 0 ]; then
            CMD+=(--agents "${AGENT_FILES[@]}")
          fi

          printf 'Running: '
          printf '%q ' "${CMD[@]}"
          echo

          # Capture output; don't fail the workflow (warn-only mode)
          set +e
          OUTPUT=$("${CMD[@]}" 2>&1)
          EXIT_CODE=$?
          set -e

          echo "exit_code=$EXIT_CODE" >> "$GITHUB_OUTPUT"

          # Save output to file (multi-line safe)
          echo "$OUTPUT" > sv-output.txt

          echo "$OUTPUT"

      # ── Upload results for the commenting workflow ────────────────
      - name: Save metadata
        if: always()
        run: |
          mkdir -p sv-results
          echo "${{ github.event.pull_request.number }}" > sv-results/pr-number.txt
          echo "${{ steps.detect.outputs.total }}" > sv-results/total.txt
          echo "${{ steps.detect.outputs.skill_count }}" > sv-results/skill-count.txt
          echo "${{ steps.detect.outputs.agent_count }}" > sv-results/agent-count.txt
          echo "${{ steps.check.outputs.exit_code }}" > sv-results/exit-code.txt
          if [ -f sv-output.txt ]; then
            cp sv-output.txt sv-results/sv-output.txt
          fi

      - name: Upload results
        if: always()
        uses: actions/upload-artifact@bbbca2ddaa5d8feaa63e36b76fdaad77386f024f # v7
        with:
          name: skill-validator-results
          path: sv-results/
          retention-days: 1

      - name: Post skip notice if no skills changed
        if: steps.detect.outputs.total == '0'
        run: echo "No skill or agent files changed in this PR — skipping validation."
