server.py

import json
from typing import Any, Dict

from fastmcp import FastMCP

from app.api import gitlab

server = FastMCP(name="gitlab-mcp", host="localhost", port=8000, stateless_http=True)


@server.tool("gitlab://user")
def get_user_resource():
    """
    Tool: gitlab://user

    Purpose:
        Retrieves information about the currently authenticated GitLab user.

    Output:
        JSON object containing user details:
        - username
        - name
        - email (if available)
        - any other metadata provided by GitLab for the authenticated user
    """
    user = gitlab.get_gitlab_user()
    return {
        "uri": "gitlab://user",
        "name": "user",
        "title": "GitLab Authenticated User",
        "mimeType": "application/json",
        "text": json.dumps(user),
    }


@server.tool("gitlab://merge_request_changes")
def get_whole_mr_diff_by_id_and_path(mr_iid: str, encoded_path: str):
    """
    Tool: gitlab://merge_request_changes

    Purpose:
        Retrieves the full diff and metadata for a GitLab Merge Request (MR) using
        the MR IID and encoded project path.

    Input:
        - mr_iid (str): The Merge Request IID (e.g., "42")
        - encoded_path (str): URL-encoded GitLab project path (e.g., "group%2Frepo")

    Output:
        JSON object containing:
        - title
        - author
        - description
        - state
        - changes (per-file diffs)
    """

    formatted = gitlab.get_whole_mr_diff(mr_iid=mr_iid, encoded_path=encoded_path)

    formatted_dict = formatted.model_dump()

    return {
        "uri": f"gitlab://merge_request_changes/{encoded_path}/{mr_iid}",
        "name": f"MR {mr_iid} changes",
        "title": f"Merge Request {mr_iid} Diff",
        "mimeType": "application/json",
        "text": json.dumps(formatted_dict),
    }


@server.tool("gitlab://merge_request_commits")
def get_per_commit_diff_by_id_and_path(mr_iid: str, encoded_path: str):
    """
    Tool: gitlab://merge_request_commits

    Purpose:
        Retrieves per-commit diffs for a GitLab Merge Request
        using encoded project path and MR IID.

    Input:
        - mr_iid (str): Merge Request IID
        - encoded_path (str): URL-encoded project path (e.g. group%2Frepo)

    Output:
        JSON object containing per-commit diffs
    """

    formatted = gitlab.get_per_commit_diffs(encoded_path=encoded_path, mr_iid=mr_iid)

    formatted_dict = formatted.model_dump()

    return {
        "uri": f"gitlab://merge_request_commits/{encoded_path}/{mr_iid}",
        "name": f"MR {mr_iid} commits",
        "title": f"Merge Request {mr_iid} Commit Diffs",
        "mimeType": "application/json",
        "text": json.dumps(formatted_dict),
    }


@server.tool("gitlab://merge_request_discussions")
def get_merge_request_discussions_by_id_and_path(mr_iid: str, encoded_path: str) -> Dict[str, Any]:
    """
    Tool: gitlab://merge_request_discussions

    Purpose:
        Retrieves all discussions (threaded comments) for a GitLab Merge Request
        using MR IID and encoded project path.

    Input:
        - mr_iid (str): Merge Request IID (e.g., "12")
        - encoded_path (str): URL-encoded GitLab project path (e.g., "group%2Frepo")

    Output:
        MCP Resource object:
        {
            "uri": "gitlab://merge_request_discussions/<encoded_path>/<mr_iid>",
            "name": "MR <iid> discussions",
            "title": "Merge Request <iid> Discussions",
            "mimeType": "application/json",
            "text": "<JSON-encoded discussions data>"
        }
    """
    try:
        discussions = gitlab.get_merge_request_discussions(mr_iid=mr_iid, encoded_path=encoded_path)

        formatted_payload = {
            "encoded_path": encoded_path,
            "mr_iid": mr_iid,
            "discussion_count": len(discussions) if isinstance(discussions, list) else None,
            "discussions": discussions,
        }

        return {
            "uri": f"gitlab://merge_request_discussions/{encoded_path}/{mr_iid}",
            "name": f"MR {mr_iid} discussions",
            "title": f"Merge Request {mr_iid} Discussions",
            "mimeType": "application/json",
            "text": json.dumps(formatted_payload, indent=2),
        }

    except Exception as e:
        err_obj = {"error": True, "message": str(e), "mr_iid": mr_iid, "encoded_path": encoded_path}

        return {
            "uri": f"gitlab://merge_request_discussions/{encoded_path}/{mr_iid}",
            "name": "MR discussions (error)",
            "title": "Merge Request Discussions — Error",
            "mimeType": "application/json",
            "text": json.dumps(err_obj, indent=2),
        }


@server.tool("gitlab://commit_diff")
def get_commit_diff_by_path_and_sha(encoded_path: str, sha: str) -> Dict[str, Any]:
    """
    Tool: gitlab://commit_diff

    Purpose:
        Retrieves the diff for a specific commit in a GitLab project
        using an encoded project path and commit SHA.

    Input:
        - encoded_path (str): URL-encoded GitLab project path (e.g., "group%2Frepo")
        - sha (str): Commit SHA

    Output:
        Resource object MCP expects:
        {
            "uri": "gitlab://commit_diff/<encoded_path>/<sha>",
            "name": "Commit <sha> diff",
            "title": "Commit <sha> Diff",
            "mimeType": "application/json",
            "text": "<JSON-encoded commit diff data>"
        }
    """
    try:
        commit_diff_response = gitlab.get_commit_diff(encoded_path=encoded_path, sha=sha)

        commit_diff_dict = commit_diff_response.model_dump()

        return {
            "uri": f"gitlab://commit_diff/{encoded_path}/{sha}",
            "name": f"Commit {sha} diff",
            "title": f"Commit {sha} Diff",
            "mimeType": "application/json",
            "text": json.dumps(commit_diff_dict, indent=2),
        }

    except Exception as e:
        err_obj = {"error": True, "message": str(e), "encoded_path": encoded_path, "sha": sha}

        return {
            "uri": f"gitlab://commit_diff/{encoded_path}/{sha}",
            "name": "Commit diff (error)",
            "title": "Commit Diff — Error",
            "mimeType": "application/json",
            "text": json.dumps(err_obj, indent=2),
        }


if __name__ == "__main__":
    server.run(transport="http", host="127.0.0.1", port=8000, stateless_http=True)