Add GitHub PR to Launchpad MP comment mirroring tool

[Copilot]

Implements a Temporal workflow that mirrors GitHub PR comments (issue + review comments) to Launchpad Merge Proposals with fingerprint-based deduplication for idempotency.

Architecture

Database Layer

• MirroredComment model with SHA256 fingerprint for deduplication
• Alembic migration d4f9a1b2c3e5 adds mirrored_comment table with unique constraint on fingerprint
• MirroredCommentsRepository for persistence and duplicate detection

Workflow

• MirrorPullRequestCommentsWorkflow orchestrates 5 activities:
  • parse_input - validates URLs, extracts identifiers
  • fetch_github_comments - retrieves issue/review comments via GitHub API
  • filter_deduplicate - queries DB for existing fingerprints
  • post_launchpad_comments - posts to MP via launchpadlib
  • record_sync - persists metadata and status
• Retry policies on network-bound activities (3 attempts, exponential backoff)

API

• POST /v1/tools/mirror-pr-comments endpoint (authenticated)
• Optional flags: include_outdated (review comments), include_review_states (approval summaries)
• Returns workflow ID for async tracking

GitHub Integration

• Normalizes issue and review comments into UnifiedComment dataclass
• Preserves file/line context for review comments
• Optionally fetches review approval/rejection states as pseudo-comments

Launchpad Integration

• Formats comments with context headers: [File: path/to/file.py | Line: 123]
• Anonymous login via launchpadlib

Usage

# Start workflow
curl -X POST /v1/tools/mirror-pr-comments \
  -H "Content-Type: application/json" \
  -d '{
    "github_pr_url": "https://github.com/owner/repo/pull/123",
    "launchpad_mp_url": "https://code.launchpad.net/~owner/project/+merge/456"
  }'

# Returns: {"workflow_id": "mirror-pr-comments-<hash>", "status": "started"}

Fingerprinting ensures re-running the workflow skips already-mirrored comments. Requires GITHUB_TOKEN environment variable.

Original prompt

Overview

Add a new productivity tool that mirrors all open comments from a GitHub Pull Request (issue comments + review comments) onto a specified Launchpad Merge Proposal (MP). This should follow the existing architectural patterns used for the current Temporal-based tool that converts a Launchpad Merge Proposal into a GitHub Pull Request.

Objectives

1. Provide an API endpoint that accepts:
   • github_pr_url
   • launchpad_mp_url
   • Options: include_outdated (bool), include_review_states (bool)
2. Start a Temporal workflow (MirrorPullRequestCommentsWorkflow) that:
   • Parses and validates both URLs.
   • Fetches all open comments from the GitHub PR (issue comments + review comments; optionally include outdated review comments).
   • Normalizes comments into a unified internal structure.
   • Deduplicates against already mirrored comments using fingerprinting to ensure idempotency.
   • Posts new comments to the Launchpad Merge Proposal via launchpadlib.
   • Records sync metadata (counts, timestamps) in the database.
   • Returns a result object containing counts of fetched, posted, skipped, and errored comments.
3. Persist mirrored comments for idempotency & audit.
4. Add Alembic migration for the new table.
5. Add tests for workflow logic, idempotency, and API endpoint.

Technical Requirements

Workflow & Activities

Create MirrorPullRequestCommentsWorkflow with activities:

• parse_input – validate and extract owner, repo, PR number, and MP identifier.
• fetch_github_comments – uses GitHub REST API to collect issue and review comments.
• filter_deduplicate – checks stored fingerprints in DB and returns only new comments.
• post_launchpad_comments – posts comments to Launchpad MP using launchpadlib.
• record_sync – stores summary and mirrored comment records (status posted/skipped/error).

Retry policies: Use Temporal default with exponential backoff for network-bound activities. Ensure activities have reasonable start_to_close_timeout values.

Data Model

Add SQLAlchemy model MirroredComment with columns:

• id (PK)
• fingerprint (unique; sha256 of "{source}:{comment_id}:{body}")
• github_comment_id
• github_source (issue|review)
• mp_identifier (string, e.g., project:merge_number)
• created_at
• posted_at
• status (pending|posted|skipped|error)
• error_message (nullable)

Create Alembic migration to add the mirrored_comments table and index/unique constraint on fingerprint.

GitHub Integration

Use environment variable GITHUB_TOKEN. Endpoints:

• Issue comments: GET /repos/{owner}/{repo}/issues/{number}/comments
• Review comments: GET /repos/{owner}/{repo}/pulls/{number}/comments
  Normalize into unified dataclass UnifiedComment (fields: source, id, author_login, body, created_at, path, line, fingerprint).
  Optionally (if include_review_states), also capture review events (GET /repos/{owner}/{repo}/pulls/{number}/reviews) and post a summary comment (e.g., "Review by X: APPROVED" or "CHANGES_REQUESTED") to Launchpad. This can be done by treating review state summaries as pseudo-comments with distinct fingerprint format review_state:{review_id}:{state}.

Launchpad Integration

Reuse existing Launchpad authentication pattern from the current tool. Implement a helper service (e.g., services/launchpad_comments.py) with function to post a textual comment to the Merge Proposal. Prefix review comments with file/line context if available, e.g.:
[File: path/to/file.py | Line: 123]\nOriginal review comment body...

API Endpoint

Add FastAPI route: POST /tools/mirror-pr-comments
Body JSON schema:

{
  "github_pr_url": "https://github.com/owner/repo/pull/123",
  "launchpad_mp_url": "https://code.launchpad.net/~owner/project/+merge/456",
  "include_outdated": false,
  "include_review_states": false
}

Response:

{
  "workflow_id": "mirror-pr-comments-<hash>",
  "status": "started"
}

Idempotency & Deduplication

Fingerprints ensure no duplicate posting. Before posting, query DB for existing fingerprints for the same mp_identifier. Skip those already present. Record skipped counts.

Observability

Log structured entries per activity including workflow_id, counts, and partial (truncated) comment bodies (first 80 chars). Provide final summary metrics via logs. (Optional future enhancement: integrate with metrics system if one exists.)

Error Handling

• Invalid URLs -> workflow failure (raise early).
• GitHub 404 -> fail workflow with clear message.
• Launchpad posting failures -> mark comment as error; continue with others.
• Rate limiting (HTTP 403 / 429) -> rely on Temporal retries; optionally inspect headers to determine backoff.

Configuration

Add any new env vars to documentation (DEVELOPMENT.md): GITHUB_TOKEN. Confirm Launchpad credentials already documented; extend if needed.

Testing

Add unit tests:

• Fingerprint generation.
• Deduplication logic.
• Parsing URLs (...

This pull request was created as a result of the following prompt from Copilot chat.

Overview

Add a new productivity tool that mirrors all open comments from a GitHub Pull Request (issue comments + review comments) onto a specified Launchpad Merge Proposal (MP). This should follow the existing architectural patterns used for the current Temporal-based tool that converts a Launchpad Merge Proposal into a GitHub Pull Request.

Objectives

1. Provide an API endpoint that accepts:
   • github_pr_url
   • launchpad_mp_url
   • Options: include_outdated (bool), include_review_states (bool)
2. Start a Temporal workflow (MirrorPullRequestCommentsWorkflow) that:
   • Parses and validates both URLs.
   • Fetches all open comments from the GitHub PR (issue comments + review comments; optionally include outdated review comments).
   • Normalizes comments into a unified internal structure.
   • Deduplicates against already mirrored comments using fingerprinting to ensure idempotency.
   • Posts new comments to the Launchpad Merge Proposal via launchpadlib.
   • Records sync metadata (counts, timestamps) in the database.
   • Returns a result object containing counts of fetched, posted, skipped, and errored comments.
3. Persist mirrored comments for idempotency & audit.
4. Add Alembic migration for the new table.
5. Add tests for workflow logic, idempotency, and API endpoint.

Technical Requirements

Workflow & Activities

Create MirrorPullRequestCommentsWorkflow with activities:

• parse_input – validate and extract owner, repo, PR number, and MP identifier.
• fetch_github_comments – uses GitHub REST API to collect issue and review comments.
• filter_deduplicate – checks stored fingerprints in DB and returns only new comments.
• post_launchpad_comments – posts comments to Launchpad MP using launchpadlib.
• record_sync – stores summary and mirrored comment records (status posted/skipped/error).

Retry policies: Use Temporal default with exponential backoff for network-bound activities. Ensure activities have reasonable start_to_close_timeout values.

Data Model

Add SQLAlchemy model MirroredComment with columns:

• id (PK)
• fingerprint (unique; sha256 of "{source}:{comment_id}:{body}")
• github_comment_id
• github_source (issue|review)
• mp_identifier (string, e.g., project:merge_number)
• created_at
• posted_at
• status (pending|posted|skipped|error)
• error_message (nullable)

Create Alembic migration to add the mirrored_comments table and index/unique constraint on fingerprint.

GitHub Integration

Use environment variable GITHUB_TOKEN. Endpoints:

• Issue comments: GET /repos/{owner}/{repo}/issues/{number}/comments
• Review comments: GET /repos/{owner}/{repo}/pulls/{number}/comments
  Normalize into unified dataclass UnifiedComment (fields: source, id, author_login, body, created_at, path, line, fingerprint).
  Optionally (if include_review_states), also capture review events (GET /repos/{owner}/{repo}/pulls/{number}/reviews) and post a summary comment (e.g., "Review by X: APPROVED" or "CHANGES_REQUESTED") to Launchpad. This can be done by treating review state summaries as pseudo-comments with distinct fingerprint format review_state:{review_id}:{state}.

Launchpad Integration

Reuse existing Launchpad authentication pattern from the current tool. Implement a helper service (e.g., services/launchpad_comments.py) with function to post a textual comment to the Merge Proposal. Prefix review comments with file/line context if available, e.g.:
[File: path/to/file.py | Line: 123]\nOriginal review comment body...

API Endpoint

Add FastAPI route: POST /tools/mirror-pr-comments
Body JSON schema:

{
  "github_pr_url": "https://github.com/owner/repo/pull/123",
  "launchpad_mp_url": "https://code.launchpad.net/~owner/project/+merge/456",
  "include_outdated": false,
  "include_review_states": false
}

Response:

{
  "workflow_id": "mirror-pr-comments-<hash>",
  "status": "started"
}

Idempotency & Deduplication

Fingerprints ensure no duplicate posting. Before posting, query DB for existing fingerprints for the same mp_identifier. Skip those already present. Record skipped counts.

Observability

Log structured entries per activity including workflow_id, counts, and partial (truncated) comment bodies (first 80 chars). Provide final summary metrics via logs. (Optional future enhancement: integrate with metrics system if one exists.)

Error Handling

• Invalid URLs -> workflow failure (raise early).
• GitHub 404 -> fail workflow with clear message.
• Launchpad posting failures -> mark comment as error; continue with others.
• Rate limiting (HTTP 403 / 429) -> rely on Temporal retries; optionally inspect headers to determine backoff.

Configuration

Add any new env vars to documentation (DEVELOPMENT.md): GITHUB_TOKEN. Confirm Launchpad credentials already documented; extend if needed.

Testing

Add unit tests:

• Fingerprint generation.
• Deduplication logic.
• Parsing URLs (valid/invalid cases).
  Mock tests:
• GitHub API responses (issue + review comments + optional reviews).
• Launchpad posting success/failure.
  Workflow integration test:
• Use Temporal test harness (if set up) to execute workflow with mocked activities.
  API test:
• Use FastAPI TestClient to trigger endpoint; assert workflow start call.

File Additions / Modifications (Proposed)

New files (paths may be adjusted to match existing project layout):

• spaghettihub/workflows/mirror_pr_comments.py (workflow + activities skeleton)
• spaghettihub/api/routes/mirror_comments.py (API endpoint)
• spaghettihub/db/models/mirrored_comments.py (SQLAlchemy model)
• spaghettihub/services/github_comments.py (GitHub fetch helpers)
• spaghettihub/services/launchpad_comments.py (Launchpad posting helper)
• alembic/versions/<timestamp>_add_mirrored_comments_table.py (migration)
• Update spaghettihub/db/__init__.py or model registry if needed.
• Update DEVELOPMENT.md to document usage & env vars.
• Optionally add tests/ modules for each new component.

Implementation Notes

• Use aiohttp (already in requirements) for async GitHub calls.
• Ensure proper conversion of GitHub timestamps to datetime objects (ISO8601 parsing).
• When posting review comments include file context header.
• Keep Temporal task queue consistent with existing workflows (e.g., spaghettihub-tools).

Acceptance Criteria

• Calling the new API endpoint starts a Temporal workflow and returns a workflow id.
• Workflow fetches comments from a sample PR and posts them to a target MP (when credentials valid) without duplicates upon re-run.
• Database persists mirrored comments with unique fingerprints.
• Tests cover key logic paths.
• Documentation updated.

Out of Scope (Future Enhancements)

• Bi-directional sync.
• Editing/deleting mirrored comments when originals change.
• Advanced rate-limit backoff strategy.
• Metrics export to external system.

Please implement the above with clean, documented code following existing repository style conventions.

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