name: "Maintenance: Rewrite kernel configs"

on:
  schedule:
    - cron: "0 0 * * MON"
  workflow_dispatch:

permissions:
  contents: write
  pull-requests: write

jobs:
  build-matrix:
    name: Build dynamic matrix
    runs-on: super
    outputs:
      matrix: ${{ steps.gen.outputs.matrix }}
      count: ${{ steps.gen.outputs.count }}
    steps:
      - uses: actions/checkout@v6
      - name: "Produce inventory JSON"
        run: |

          ./compile.sh inventory-boards

      - name: Build matrix from inventory (simple sanitize)
        id: gen
        shell: bash
        run: |
          set -euo pipefail
          JSON="output/info/image-info.json"

          tmp="$(mktemp)"

          jq -c '
            def norm_branches:
              if . == null then []
              elif (type=="string") then ( gsub("[,\\s]+";" ") | split(" ") | map(select(length>0)) )
              elif (type=="array")  then ( map(tostring) | map(select(length>0)) )
              else [] end;

            # 1) Expand to rows: (board, linuxfamily, branch)
            [ .[] 
              | {
                  board:       (.out.HOST // .in.inventory.BOARD // ""),
                  linuxfamily: (.out.LINUXFAMILY // .in.inventory.BOARDFAMILY // ""),
                  branches:    ((.in.inventory.BOARD_POSSIBLE_BRANCHES
                                // .in.inventory.BOARD_TOP_LEVEL_VARS.BOARD_POSSIBLE_BRANCHES)
                                | norm_branches)
                }
              | select((.board|length>0) and (.linuxfamily|length>0) and (.branches|length>0))
              | . as $o
              | $o.branches[]
              | { board: $o.board, linuxfamily: $o.linuxfamily, branch: . }
            ]
            # 2) Remove exact triplet duplicates
            | unique_by([.linuxfamily,.branch,.board])
            # 3) If same (board,branch) appears in multiple families, keep the one with smallest family (lexicographic)
            | sort_by(.board, .branch, .linuxfamily)
            | group_by([.board,.branch]) | map(.[0])
            # 4) If multiple boards share same (family,branch), keep smallest board (lexicographic)
            | sort_by(.linuxfamily, .branch, .board)
            | group_by([.linuxfamily,.branch]) | map(.[0])
          ' "$JSON" > "$tmp"

          echo "count=$(jq 'length' "$tmp")" >> "$GITHUB_OUTPUT"
          echo "matrix=$(jq -c . "$tmp")" >> "$GITHUB_OUTPUT"

  rewrite-configs:
    name: "Rewrite ${{ matrix.board }} (${{ matrix.branch }})"
    needs: build-matrix
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        include: ${{ fromJson(needs.build-matrix.outputs.matrix) }}
    steps:
      - uses: actions/checkout@v6
        with:
          fetch-depth: 0

      - name: Run rewrite-kernel-config
        env:
          BOARD: ${{ matrix.board }}
          BRANCH: ${{ matrix.branch }}
          DOCKER_ARMBIAN_BASE_IMAGE: "debian:trixie"
        run: |

          set -euo pipefail
          ./compile.sh rewrite-kernel-config BOARD=$BOARD BRANCH=$BRANCH DOCKER_ARMBIAN_BASE_IMAGE="$DOCKER_ARMBIAN_BASE_IMAGE"

      - name: Collect changes into artifact (added/modified/renamed only) + step summary
        id: collect
        shell: bash
        run: |

          set -euo pipefail

          # Get changed paths, NUL-delimited (safe for spaces)
          mapfile -d '' -t CHANGED < <(git diff -z --name-only --diff-filter=ACMR || true)

          if [[ ${#CHANGED[@]} -eq 0 ]]; then
            echo "nothing_to_upload=true" >> "$GITHUB_OUTPUT"
            {
              echo "### No changes in this job"
              echo ""
              echo "- Family: **${{ matrix.linuxfamily }}**"
              echo "- Branch: **${{ matrix.branch }}**"
              echo "- Board:  **${{ matrix.board }}**"
            } >> "$GITHUB_STEP_SUMMARY"
            exit 0
          fi

          JOB_ID="${{ matrix.linuxfamily }}-${{ matrix.branch }}-${{ matrix.board }}"
          ROOT="artifact/${JOB_ID}/payload"
          mkdir -p "$ROOT"

          # Copy files while preserving directory structure
          printf '%s\0' "${CHANGED[@]}" | xargs -0 -I{} cp --parents -a -- "{}" "$ROOT/"

          # --- Build GitHub Step Summary with numstat (additions/deletions) ---
          # Note: numstat shows '-' for binary changes; we treat those as 0
          NUMSTAT="$(mktemp)"
          git diff --numstat --diff-filter=ACMR > "$NUMSTAT" || true

          total_add=0
          total_del=0
          file_count=0

          {
            echo "### Changes for \`$JOB_ID\`"
            echo ""
            echo "| File | + | - | Δ |"
            echo "|---|---:|---:|---:|"
          } >> "$GITHUB_STEP_SUMMARY"

          # Read tab-delimited: added<TAB>deleted<TAB>path
          while IFS=$'\t' read -r add del path; do
            [[ -z "${path:-}" ]] && continue

            # Handle binary markers '-'
            [[ "$add" =~ ^[0-9]+$ ]] || add=0
            [[ "$del" =~ ^[0-9]+$ ]] || del=0

            delta=$(( add - del ))
            total_add=$(( total_add + add ))
            total_del=$(( total_del + del ))
            file_count=$(( file_count + 1 ))

            # Escape pipes in path for Markdown safety
            path_esc="${path//|/\\|}"

            printf '| %s | %d | %d | %d |\n' "$path_esc" "$add" "$del" "$delta" >> "$GITHUB_STEP_SUMMARY"
          done < "$NUMSTAT"

          {
            echo ""
            echo "**Files changed:** $file_count"
            echo ""
            printf "**Total lines:** +%d / -%d (Δ %d)\n" "$total_add" "$total_del" "$(( total_add - total_del ))"
          } >> "$GITHUB_STEP_SUMMARY"

      - name: Upload artifact (per job; unique; overwrite safe)
        if: steps.collect.outputs.nothing_to_upload != 'true'
        uses: actions/upload-artifact@v7.0.0
        with:
          name: changes-${{ matrix.linuxfamily }}-${{ matrix.branch }}-${{ matrix.board }}-${{ github.run_attempt }}
          path: artifact/${{ matrix.linuxfamily }}-${{ matrix.branch }}-${{ matrix.board }}
          if-no-files-found: ignore
          retention-days: 7
          overwrite: true

  aggregate-pr:
    name: Aggregate changes & open PR
    needs: [build-matrix, rewrite-configs]
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v6
        with:
          fetch-depth: 0

      - name: Download all change artifacts (no merge)
        continue-on-error: true
        uses: actions/download-artifact@v8
        with:
          path: _artifacts
          pattern: changes-*

      - name: Apply all artifacts
        shell: bash
        run: |
          set -euo pipefail
          shopt -s nullglob

          # Count artifacts
          FOUND=0
          for d in _artifacts/changes-*; do
            [[ -d "$d" ]] || continue
            FOUND=$((FOUND+1))
            # Apply payload files (add/update)
            if [[ -d "$d/payload" ]]; then
              # rsync preserves paths; trailing slashes mean "copy contents"
              rsync -a "$d/payload/" .
            fi
            # Accumulate deletions
            if [[ -f "$d/deletions.txt" ]]; then
              cat "$d/deletions.txt" >> /tmp/all_deletions.txt
            fi
          done
          echo "Aggregated artifacts: $FOUND"

          # Apply deletions (dedup + ignore non-existent)
          if [[ -s /tmp/all_deletions.txt ]]; then
            sort -u /tmp/all_deletions.txt > /tmp/all_deletions_uniq.txt
            xargs -r -d '\n' git rm -f --ignore-unmatch < /tmp/all_deletions_uniq.txt || true
          fi

          # Did anything actually change?
          if git diff --quiet; then
            echo "NO_CHANGES=true" >> "$GITHUB_ENV"
          fi

      - name: Build PR body (summary table)
        if: env.NO_CHANGES != 'true'
        shell: bash
        run: |
          set -euo pipefail
          rm -rf _artifacts || true
          mkdir -p output/info

          # Per-file stats
          git diff --numstat > output/info/numstat.txt || true

          total_add=0; total_del=0; files=0
          {
            echo "# Rewrite kernel configs"
            echo
            echo "### What this PR does"
            echo "- Regenerates and **synchronizes Linux kernel config fragments** across boards/families based on the prepared inventory."
            echo "- Runs \`./compile.sh rewrite-kernel-config\` for each scheduled (family, branch) and aggregates all changes into **one PR**."
            echo "- No userspace changes; only **Kconfig option** updates (enable/disable/modules/values) aligned with the targeted kernel branches."
            echo
            echo "### How it was produced"
            echo
            echo "This PR is produced from [this](/armbian/build/tree/main/.github/workflows/maintenance-rewrite-kernel-configs.yml) GHA script."
            echo
            echo "1. Built a matrix: \`./compile.sh inventory-boards\` (deduped, sanitized)."
            echo "2. Executed \`rewrite-kernel-config\` per matrix."
            echo "3. Collected only changed files from each job as artifacts; aggregated and committed them here."
            echo
            echo "### Review tips"
            echo "- Skim the table below for big deltas; open those configs to verify intent."
            echo "- If a particular change is undesirable, comment on that file and we can exclude/adjust and re-run."
            echo
            echo "### Files changed"
            echo
            echo "| File | + | - | Δ |"
            echo "|---|---:|---:|---:|"
            while IFS=$'\t' read -r add del path; do
              [[ -z "${path:-}" ]] && continue
              [[ "$add" =~ ^[0-9]+$ ]] || add=0
              [[ "$del" =~ ^[0-9]+$ ]] || del=0
              delta=$(( add - del ))
              total_add=$(( total_add + add ))
              total_del=$(( total_del + del ))
              files=$(( files + 1 ))
              path_esc="${path//|/\\|}"
              printf "| %s | %d | %d | %d |\n" "$path_esc" "$add" "$del" "$delta"
            done < output/info/numstat.txt
            echo
            printf "**Files:** %d  •  **Lines:** +%d / -%d  (Δ %d)\n" "$files" "$total_add" "$total_del" "$(( total_add - total_del ))"
            echo

            if compgen -G "output/info/annotated-configs/*.md" > /dev/null; then
              echo "## Annotated configs"
              for f in output/info/annotated-configs/*.md; do
                echo "- ${f}"
              done
              echo
            fi
          } > PR_BODY.md

      - name: Open / Update PR
        if: env.NO_CHANGES != 'true'
        uses: peter-evans/create-pull-request@v8
        with:
          add-paths: |
            config/kernel/*
          token: ${{ secrets.GITHUB_TOKEN }}
          branch: update-kernel-configs
          delete-branch: true
          title: "`Automatic` kernel config rewrite"
          commit-message: "Automatic: kernel config rewrite"
          body-path: PR_BODY.md
          labels: |
            Needs review