kind: WavePipeline
metadata:
  name: audit-dead-code-review
  description: "Scan PR-changed files for dead code and post a review comment"
  release: true

requires:
  tools:
    - go
    - gh

skills:
  - software-design

input:
  source: cli
  example: "https://github.com/re-cinq/wave/pull/42"

steps:
  - id: scan
    persona: navigator
    model: claude-haiku
    workspace:
      mount:
        - source: ./
          target: /project
          mode: readonly
    exec:
      type: prompt
      source: |
        Scan for dead or redundant code in the files changed by: {{ input }}

        ## Scope

        Only scan files changed in the given pull request. Use `{{ forge.cli_tool }} {{ forge.pr_command }} diff` to
        identify the changed files, then analyze only those files for dead code.

        ## What to Look For

        1. **Unused exports**: Exported functions, types, constants, or variables
           that are never referenced outside their package.

        2. **Unreachable code**: Code after return/panic, impossible branches,
           dead switch cases.

        3. **Orphaned files**: Files not imported by any other file in the project.

        4. **Redundant code**: Duplicate functions, copy-paste blocks,
           wrappers that add no value.

        5. **Stale tests**: Tests for functions that no longer exist,
           or tests that test nothing meaningful.

        6. **Unused dependencies**: Imports that are no longer needed.

        7. **Commented-out code**: Large blocks of commented code that
           should be deleted (git has history).

        8. **Duplicate signatures**: Functions with identical signatures across
           packages that could be consolidated.

        ## Verification

        For each finding, verify it's truly dead:
        - Grep for all references across the entire codebase
        - Check for reflect-based or string-based usage
        - Check if it's part of an interface implementation
        - Check for build tag conditional compilation

        Produce a structured JSON result matching the contract schema.
        Only include findings with high or medium confidence. Skip low confidence.
    output_artifacts:
      - name: scan_results
        path: .wave/output/dead-code-scan.json
        type: json
    retry:
      policy: patient
      max_attempts: 2
    handover:
      contract:
        type: json_schema
        source: .wave/output/dead-code-scan.json
        schema_path: .wave/contracts/dead-code-scan.schema.json
        on_failure: retry

  - id: compose
    persona: summarizer
    model: claude-haiku
    dependencies: [scan]
    memory:
      inject_artifacts:
        - step: scan
          artifact: scan_results
          as: findings
    exec:
      type: prompt
      source: |
        Compose a dead code review comment from the scan findings.

        Read the injected findings and produce a markdown summary suitable for
        posting as a PR review comment.

        ## Format

        If zero findings:
        ```
        No dead code found in the changed files.
        ```

        If findings exist:
        ```
        ## Dead Code Review

        **Findings**: <total_count> items found in changed files

        ### Summary by Type
        | Type | Count |
        |------|-------|
        | ... | N |

        ### Findings

        For each finding (sorted by confidence, high first):
        - **[DC-001]** (`type`) `location` — description
          Suggested action: `suggested_action`

        ---
        *Generated by [Wave](https://github.com/re-cinq/wave) dead-code-review pipeline*
        ```

        Do NOT include a title/header line — the publish step adds one.
    output_artifacts:
      - name: review_comment
        path: .wave/output/review-comment.md
        type: markdown
    handover:
      contract:
        type: non_empty_file
        source: .wave/output/review-comment.md

  - id: publish
    persona: "gitea-commenter"
    dependencies: [compose]
    memory:
      inject_artifacts:
        - step: compose
          artifact: review_comment
          as: review_summary
    exec:
      type: prompt
      source: |
        Post the dead code review as a PR comment.

        The original input was: {{ input }}
        Extract the PR number or URL from the input.

        1. Write the review content to a temp file, then post it as a PR comment:
           cat > /tmp/dead-code-review-comment.md <<'REVIEW_EOF'
           ## Dead Code Review (Wave Pipeline)

           <review content>

           ---
           *Generated by [Wave](https://github.com/re-cinq/wave) dead-code-review pipeline*
           REVIEW_EOF
           {{ forge.cli_tool }} {{ forge.pr_command }} comment <PR_NUMBER_OR_URL> --body-file /tmp/dead-code-review-comment.md

    output_artifacts:
      - name: publish-result
        path: .wave/output/publish-result.json
        type: json
    retry:
      policy: aggressive
      max_attempts: 2
    handover:
      contract:
        type: json_schema
        source: .wave/output/publish-result.json
        schema_path: .wave/contracts/gh-pr-comment-result.schema.json
        must_pass: true
        on_failure: retry
    outcomes:
      - type: url
        extract_from: .wave/output/publish-result.json
        json_path: .comment_url
        label: "Dead Code Review Comment"