import { Server } from "@modelcontextprotocol/sdk/server/index.js";
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
import {
    CallToolRequestSchema,
    ListToolsRequestSchema,
    ListResourcesRequestSchema,
    ReadResourceRequestSchema,
    SubscribeRequestSchema,
    UnsubscribeRequestSchema,
    Tool,
    Resource,
} from "@modelcontextprotocol/sdk/types.js";
import { z } from "zod";
import axios from "axios";

const GITEA_HOST = process.env.GITEA_HOST || "https://git.infra.mintel.me";
const GITEA_ACCESS_TOKEN = process.env.GITEA_ACCESS_TOKEN;

if (!GITEA_ACCESS_TOKEN) {
    console.error("Error: GITEA_ACCESS_TOKEN environment variable is required");
    process.exit(1);
}

const giteaClient = axios.create({
    baseURL: `${GITEA_HOST.replace(/\/$/, '')}/api/v1`,
    headers: {
        Authorization: `token ${GITEA_ACCESS_TOKEN}`,
    },
});

const LIST_PIPELINES_TOOL: Tool = {
    name: "gitea_list_pipelines",
    description: "List recent action runs (pipelines) for a specific repository",
    inputSchema: {
        type: "object",
        properties: {
            owner: { type: "string", description: "Repository owner (e.g., 'mmintel')" },
            repo: { type: "string", description: "Repository name (e.g., 'at-mintel')" },
            limit: { type: "number", description: "Number of runs to fetch (default: 5)" },
        },
        required: ["owner", "repo"],
    },
};

const GET_PIPELINE_LOGS_TOOL: Tool = {
    name: "gitea_get_pipeline_logs",
    description: "Get detailed logs for a specific pipeline run or job",
    inputSchema: {
        type: "object",
        properties: {
            owner: { type: "string", description: "Repository owner" },
            repo: { type: "string", description: "Repository name" },
            run_id: { type: "number", description: "ID of the action run" },
        },
        required: ["owner", "repo", "run_id"],
    },
};

// Subscription State
const subscriptions = new Set<string>();
const runStatusCache = new Map<string, string>(); // uri -> status

const server = new Server(
    {
        name: "gitea-mcp-native",
        version: "1.0.0",
    },
    {
        capabilities: {
            tools: {},
            resources: { subscribe: true }, // Enable subscriptions
        },
    }
);

// --- Tools ---
server.setRequestHandler(ListToolsRequestSchema, async () => {
    return {
        tools: [LIST_PIPELINES_TOOL, GET_PIPELINE_LOGS_TOOL],
    };
});

server.setRequestHandler(CallToolRequestSchema, async (request) => {
    if (request.params.name === "gitea_list_pipelines") {
        // ... (Keeping exact same implementation as before for brevity)
        const { owner, repo, limit = 5 } = request.params.arguments as any;

        try {
            const runsResponse = await giteaClient.get(`/repos/${owner}/${repo}/actions/runs`, {
                params: { limit },
            });

            const runs = (runsResponse.data.workflow_runs || []) as any[];
            const enhancedRuns = await Promise.all(
                runs.map(async (run: any) => {
                    try {
                        const jobsResponse = await giteaClient.get(`/repos/${owner}/${repo}/actions/runs/${run.id}/jobs`);
                        const jobs = (jobsResponse.data.jobs || []) as any[];
                        return {
                            id: run.id,
                            name: run.name,
                            status: run.status,
                            created_at: run.created_at,
                            jobs: jobs.map((job: any) => ({
                                id: job.id,
                                name: job.name,
                                status: job.status,
                                conclusion: job.conclusion
                            }))
                        };
                    } catch (e) {
                        return { id: run.id, name: run.name, status: run.status, created_at: run.created_at, jobs: [] };
                    }
                })
            );

            return {
                content: [{ type: "text", text: JSON.stringify(enhancedRuns, null, 2) }],
            };
        } catch (error: any) {
            return { isError: true, content: [{ type: "text", text: `Error fetching pipelines: ${error.message}` }] };
        }
    }

    if (request.params.name === "gitea_get_pipeline_logs") {
        const { owner, repo, run_id } = request.params.arguments as any;
        try {
            const jobsResponse = await giteaClient.get(`/repos/${owner}/${repo}/actions/runs/${run_id}/jobs`);
            const jobs = (jobsResponse.data.jobs || []) as any[];
            const logs = jobs.map((job: any) => ({
                job_id: job.id,
                job_name: job.name,
                status: job.status,
                conclusion: job.conclusion,
                steps: (job.steps || []).map((step: any) => ({
                    name: step.name,
                    status: step.status,
                    conclusion: step.conclusion
                }))
            }));

            return { content: [{ type: "text", text: JSON.stringify(logs, null, 2) }] };
        } catch (error: any) {
            return { isError: true, content: [{ type: "text", text: `Error: ${error.message}` }] };
        }
    }

    throw new Error(`Unknown tool: ${request.params.name}`);
});

// --- Resources & Subscriptions ---
// We will expose a dynamic resource URI pattern: gitea://runs/{owner}/{repo}/{run_id}
server.setRequestHandler(ListResourcesRequestSchema, async () => {
    return {
        resources: [
            {
                uri: "gitea://runs",
                name: "Gitea Pipeline Runs",
                description: "Dynamic resource for subscribing to pipeline runs. Format: gitea://runs/{owner}/{repo}/{run_id}",
                mimeType: "application/json",
            }
        ],
    };
});

server.setRequestHandler(ReadResourceRequestSchema, async (request) => {
    const uri = request.params.uri;
    const match = uri.match(/^gitea:\/\/runs\/([^\/]+)\/([^\/]+)\/(\d+)$/);

    if (!match) {
        throw new Error(`Invalid resource URI. Must be gitea://runs/{owner}/{repo}/{run_id}`);
    }

    const [, owner, repo, run_id] = match;

    try {
        const runResponse = await giteaClient.get(`/repos/${owner}/${repo}/actions/runs/${run_id}`);
        const jobsResponse = await giteaClient.get(`/repos/${owner}/${repo}/actions/runs/${run_id}/jobs`);

        const resourceContent = {
            run: runResponse.data,
            jobs: jobsResponse.data
        };

        // Update internal cache when read
        runStatusCache.set(uri, runResponse.data.status);

        return {
            contents: [
                {
                    uri,
                    mimeType: "application/json",
                    text: JSON.stringify(resourceContent, null, 2),
                },
            ],
        };
    } catch (error: any) {
        throw new Error(`Failed to read Gitea resource: ${error.message}`);
    }
});

server.setRequestHandler(SubscribeRequestSchema, async (request) => {
    const uri = request.params.uri;
    if (!uri.startsWith("gitea://runs/")) {
        throw new Error("Only gitea://runs resources can be subscribed to");
    }
    subscriptions.add(uri);
    console.error(`Client subscribed to ${uri}`);
    return {};
});

server.setRequestHandler(UnsubscribeRequestSchema, async (request) => {
    const uri = request.params.uri;
    subscriptions.delete(uri);
    console.error(`Client unsubscribed from ${uri}`);
    return {};
});

// The server polling mechanism that pushes updates to subscribed clients
async function pollSubscriptions() {
    for (const uri of subscriptions) {
        const match = uri.match(/^gitea:\/\/runs\/([^\/]+)\/([^\/]+)\/(\d+)$/);
        if (!match) continue;

        const [, owner, repo, run_id] = match;
        try {
            const runResponse = await giteaClient.get(`/repos/${owner}/${repo}/actions/runs/${run_id}`);
            const currentStatus = runResponse.data.status;
            const prevStatus = runStatusCache.get(uri);

            // If status changed (e.g. running -> completed), notify client
            if (prevStatus !== currentStatus) {
                runStatusCache.set(uri, currentStatus);

                server.notification({
                    method: "notifications/resources/updated",
                    params: { uri }
                });
                console.error(`Pushed update for ${uri}: ${prevStatus} -> ${currentStatus}`);

                // Auto-unsubscribe if completed/failed so we don't poll forever?
                // Let the client decide, or we can handle it here if requested.
            }
        } catch (e) {
            console.error(`Error polling subscription ${uri}:`, e);
        }
    }

    // Poll every 5 seconds
    setTimeout(pollSubscriptions, 5000);
}


async function run() {
    const transport = new StdioServerTransport();
    await server.connect(transport);
    console.error("Gitea MCP Native Server running on stdio");

    // Start the background poller
    pollSubscriptions();
}

run().catch((error) => {
    console.error("Fatal error:", error);
    process.exit(1);
});