# Copyright (C) Project Tick
# SPDX-License-Identifier: MIT
#
# Composite action — analyzes changed directories and parses commit messages.
# Exposes per-project boolean outputs + parsed commit info for the caller.

name: "Change Analysis"
description: >
  Detects which project directories changed in this commit/PR and parses the
  commit message (Conventional Commits). Outputs per-project flags and a
  summary report.

# ── Inputs ──────────────────────────────────────────────────────
inputs:
  event-name:
    description: "github.event_name (push, pull_request, workflow_dispatch)"
    required: true
  base-sha:
    description: "Base SHA for diff (PR base or push before)"
    required: false
    default: ""
  head-sha:
    description: "Head SHA for diff"
    required: false
    default: ""
  before-sha:
    description: "Push event before SHA"
    required: false
    default: ""
  current-sha:
    description: "Current commit SHA (github.sha)"
    required: true
  pr-title:
    description: "Pull request title (for commit message parsing on PRs)"
    required: false
    default: ""

# ── Outputs ─────────────────────────────────────────────────────
outputs:
  # Per-project change flags
  archived_changed:
    description: "true if archived/ was modified"
    value: ${{ steps.detect.outputs.archived_changed }}
  cgit_changed:
    description: "true if cgit/ was modified"
    value: ${{ steps.detect.outputs.cgit_changed }}
  cmark_changed:
    description: "true if cmark/ was modified"
    value: ${{ steps.detect.outputs.cmark_changed }}
  corebinutils_changed:
    description: "true if corebinutils/ was modified"
    value: ${{ steps.detect.outputs.corebinutils_changed }}
  forgewrapper_changed:
    description: "true if forgewrapper/ was modified"
    value: ${{ steps.detect.outputs.forgewrapper_changed }}
  genqrcode_changed:
    description: "true if genqrcode/ was modified"
    value: ${{ steps.detect.outputs.genqrcode_changed }}
  hooks_changed:
    description: "true if hooks/ was modified"
    value: ${{ steps.detect.outputs.hooks_changed }}
  images4docker_changed:
    description: "true if images4docker/ was modified"
    value: ${{ steps.detect.outputs.images4docker_changed }}
  json4cpp_changed:
    description: "true if json4cpp/ was modified"
    value: ${{ steps.detect.outputs.json4cpp_changed }}
  libnbtplusplus_changed:
    description: "true if libnbtplusplus/ was modified"
    value: ${{ steps.detect.outputs.libnbtplusplus_changed }}
  meshmc_changed:
    description: "true if meshmc/ was modified"
    value: ${{ steps.detect.outputs.meshmc_changed }}
  meta_changed:
    description: "true if meta/ was modified"
    value: ${{ steps.detect.outputs.meta_changed }}
  mnv_changed:
    description: "true if mnv/ was modified"
    value: ${{ steps.detect.outputs.mnv_changed }}
  neozip_changed:
    description: "true if neozip/ was modified"
    value: ${{ steps.detect.outputs.neozip_changed }}
  tomlplusplus_changed:
    description: "true if tomlplusplus/ was modified"
    value: ${{ steps.detect.outputs.tomlplusplus_changed }}
  ci_changed:
    description: "true if ci/ was modified"
    value: ${{ steps.detect.outputs.ci_changed }}
  github_changed:
    description: "true if .github/ was modified"
    value: ${{ steps.detect.outputs.github_changed }}
  root_changed:
    description: "true if root-level files were modified"
    value: ${{ steps.detect.outputs.root_changed }}
  # Aggregate
  changed_projects:
    description: "Comma-separated list of changed project names"
    value: ${{ steps.detect.outputs.changed_projects }}
  changed_count:
    description: "Number of changed projects"
    value: ${{ steps.detect.outputs.changed_count }}
  # Parsed commit
  commit_type:
    description: "Conventional commit type (feat, fix, chore, …)"
    value: ${{ steps.parse-commit.outputs.type }}
  commit_scope:
    description: "Conventional commit scope"
    value: ${{ steps.parse-commit.outputs.scope }}
  commit_subject:
    description: "Commit subject line"
    value: ${{ steps.parse-commit.outputs.subject }}
  commit_breaking:
    description: "true if this is a breaking change"
    value: ${{ steps.parse-commit.outputs.breaking }}
  commit_message:
    description: "Full commit message / PR title"
    value: ${{ steps.parse-commit.outputs.full_message }}

# ── Steps ───────────────────────────────────────────────────────
runs:
  using: "composite"
  steps:
    - name: Detect changed directories
      id: detect
      shell: bash
      run: |
        set -euo pipefail

        EVENT_NAME="${{ inputs.event-name }}"
        BASE_SHA="${{ inputs.base-sha }}"
        HEAD_SHA="${{ inputs.head-sha }}"
        BEFORE_SHA="${{ inputs.before-sha }}"
        CURRENT_SHA="${{ inputs.current-sha }}"

        # Determine the list of changed files
        if [[ "$EVENT_NAME" == "pull_request" ]]; then
          CHANGED_FILES=$(git diff --name-only "$BASE_SHA" "$HEAD_SHA" --)
        elif [[ "$EVENT_NAME" == "push" ]]; then
          if [[ "$BEFORE_SHA" == "0000000000000000000000000000000000000000" ]]; then
            CHANGED_FILES=$(git diff-tree --no-commit-id --name-only -r HEAD)
          else
            CHANGED_FILES=$(git diff --name-only "$BEFORE_SHA" "$CURRENT_SHA" --)
          fi
        else
          # workflow_dispatch / other: compare with parent
          CHANGED_FILES=$(git diff-tree --no-commit-id --name-only -r HEAD)
        fi

        echo "::group::Changed files"
        echo "$CHANGED_FILES"
        echo "::endgroup::"

        # All projects to detect
        PROJECTS=(
          archived cgit ci cmark corebinutils forgewrapper genqrcode
          hooks images4docker json4cpp libnbtplusplus meshmc meta
          mnv neozip tomlplusplus
        )

        CHANGED_PROJECTS=()

        for proj in "${PROJECTS[@]}"; do
          if echo "$CHANGED_FILES" | grep -q "^${proj}/"; then
            echo "${proj}_changed=true" >> "$GITHUB_OUTPUT"
            CHANGED_PROJECTS+=("$proj")
          else
            echo "${proj}_changed=false" >> "$GITHUB_OUTPUT"
          fi
        done

        # .github/ changes
        if echo "$CHANGED_FILES" | grep -q "^\.github/"; then
          echo "github_changed=true" >> "$GITHUB_OUTPUT"
          CHANGED_PROJECTS+=(".github")
        else
          echo "github_changed=false" >> "$GITHUB_OUTPUT"
        fi

        # Root-level files (CODEOWNERS, README, SECURITY, etc.)
        ROOT_MATCHES=$(echo "$CHANGED_FILES" | grep -vE "^(archived|cgit|ci|cmark|corebinutils|forgewrapper|genqrcode|hooks|images4docker|json4cpp|libnbtplusplus|meshmc|meta|mnv|neozip|tomlplusplus|LICENSES|\.github)/" || true)
        if [[ -n "$ROOT_MATCHES" ]]; then
          echo "root_changed=true" >> "$GITHUB_OUTPUT"
          CHANGED_PROJECTS+=("root")
        else
          echo "root_changed=false" >> "$GITHUB_OUTPUT"
        fi

        # Build comma-separated list
        if [[ ${#CHANGED_PROJECTS[@]} -gt 0 ]]; then
          PROJECTS_CSV=$(IFS=','; echo "${CHANGED_PROJECTS[*]}")
        else
          PROJECTS_CSV=""
        fi
        echo "changed_projects=${PROJECTS_CSV}" >> "$GITHUB_OUTPUT"
        echo "changed_count=${#CHANGED_PROJECTS[@]}" >> "$GITHUB_OUTPUT"

        echo "::notice::Changed projects (${#CHANGED_PROJECTS[@]}): ${PROJECTS_CSV}"

    - name: Parse commit message
      id: parse-commit
      shell: bash
      run: |
        set -euo pipefail

        EVENT_NAME="${{ inputs.event-name }}"
        PR_TITLE="${{ inputs.pr-title }}"

        if [[ "$EVENT_NAME" == "pull_request" && -n "$PR_TITLE" ]]; then
          FULL_MSG="$PR_TITLE"
        else
          FULL_MSG=$(git log -1 --format='%s' HEAD)
        fi

        echo "full_message<<COMMIT_MSG_EOF" >> "$GITHUB_OUTPUT"
        echo "$FULL_MSG" >> "$GITHUB_OUTPUT"
        echo "COMMIT_MSG_EOF" >> "$GITHUB_OUTPUT"

        # Parse Conventional Commits: type(scope): subject
        # Also handles: type: subject, type!: subject, type(scope)!: subject
        COMMIT_RE='^([a-zA-Z]+)(\(([^)]*)\))?(!)?\:\ (.+)$'
        if [[ "$FULL_MSG" =~ $COMMIT_RE ]]; then
          TYPE="${BASH_REMATCH[1]}"
          SCOPE="${BASH_REMATCH[3]:-}"
          BREAKING="${BASH_REMATCH[4]:-}"
          SUBJECT="${BASH_REMATCH[5]}"

          echo "type=${TYPE}" >> "$GITHUB_OUTPUT"
          echo "scope=${SCOPE}" >> "$GITHUB_OUTPUT"
          echo "subject=${SUBJECT}" >> "$GITHUB_OUTPUT"

          if [[ "$BREAKING" == "!" ]]; then
            echo "breaking=true" >> "$GITHUB_OUTPUT"
          else
            echo "breaking=false" >> "$GITHUB_OUTPUT"
          fi
        else
          echo "type=" >> "$GITHUB_OUTPUT"
          echo "scope=" >> "$GITHUB_OUTPUT"
          echo "subject=${FULL_MSG}" >> "$GITHUB_OUTPUT"
          echo "breaking=false" >> "$GITHUB_OUTPUT"
        fi

    - name: Generate summary report
      shell: bash
      run: |
        set -euo pipefail

        cat >> "$GITHUB_STEP_SUMMARY" <<'HEADER'
        # Change Analysis Report

        HEADER

        cat >> "$GITHUB_STEP_SUMMARY" <<EOF
        ## Commit Information

        | Field | Value |
        |-------|-------|
        | **SHA** | \`${{ inputs.current-sha }}\` |
        | **Event** | \`${{ inputs.event-name }}\` |
        | **Type** | \`${{ steps.parse-commit.outputs.type || 'N/A' }}\` |
        | **Scope** | \`${{ steps.parse-commit.outputs.scope || 'N/A' }}\` |
        | **Subject** | ${{ steps.parse-commit.outputs.subject }} |
        | **Breaking** | ${{ steps.parse-commit.outputs.breaking }} |

        ## Changed Projects (${{ steps.detect.outputs.changed_count }})

        | Project | Changed |
        |---------|---------|
        | archived | ${{ steps.detect.outputs.archived_changed == 'true' && '✅' || '—' }} |
        | cgit | ${{ steps.detect.outputs.cgit_changed == 'true' && '✅' || '—' }} |
        | cmark | ${{ steps.detect.outputs.cmark_changed == 'true' && '✅' || '—' }} |
        | corebinutils | ${{ steps.detect.outputs.corebinutils_changed == 'true' && '✅' || '—' }} |
        | forgewrapper | ${{ steps.detect.outputs.forgewrapper_changed == 'true' && '✅' || '—' }} |
        | genqrcode | ${{ steps.detect.outputs.genqrcode_changed == 'true' && '✅' || '—' }} |
        | hooks | ${{ steps.detect.outputs.hooks_changed == 'true' && '✅' || '—' }} |
        | images4docker | ${{ steps.detect.outputs.images4docker_changed == 'true' && '✅' || '—' }} |
        | json4cpp | ${{ steps.detect.outputs.json4cpp_changed == 'true' && '✅' || '—' }} |
        | libnbtplusplus | ${{ steps.detect.outputs.libnbtplusplus_changed == 'true' && '✅' || '—' }} |
        | meshmc | ${{ steps.detect.outputs.meshmc_changed == 'true' && '✅' || '—' }} |
        | meta | ${{ steps.detect.outputs.meta_changed == 'true' && '✅' || '—' }} |
        | mnv | ${{ steps.detect.outputs.mnv_changed == 'true' && '✅' || '—' }} |
        | neozip | ${{ steps.detect.outputs.neozip_changed == 'true' && '✅' || '—' }} |
        | tomlplusplus | ${{ steps.detect.outputs.tomlplusplus_changed == 'true' && '✅' || '—' }} |
        | ci | ${{ steps.detect.outputs.ci_changed == 'true' && '✅' || '—' }} |
        | .github | ${{ steps.detect.outputs.github_changed == 'true' && '✅' || '—' }} |
        | root files | ${{ steps.detect.outputs.root_changed == 'true' && '✅' || '—' }} |

        ---
        > **Changed:** \`${{ steps.detect.outputs.changed_projects }}\`
        EOF