import express, { Request, Response, NextFunction } from 'express';
import cors from 'cors';
import * as fs from 'fs';
import * as path from 'path';
import * as crypto from 'crypto';
import { execSync } from 'child_process';
import { createJob, getJob, listJobs, updateJob } from './job-store';
import { runAgent } from './agent-runner';
import { runSessionAgent } from './agent-session-runner';
import { AGENTS } from './agents';
import { ToolContext } from './tools';
import { PROTECTED_GITEA_REPOS } from './tools/security';
import { orchestratorChat, listSessions, clearSession } from './orchestrator';
import { atlasChat, listAtlasSessions, clearAtlasSession } from './atlas';
import { LLMMessage, createLLM } from './llm';
import { getTheiaContainer, isTheiaSyncAvailable } from './theia-exec';

const app = express();
app.use(cors());

const startTime = new Date();

// Raw body capture for webhook HMAC — must come before express.json()
app.use('/webhook/gitea', express.raw({ type: '*/*' }));

app.use(express.json());

const PORT = process.env.PORT || 3333;

// ---------------------------------------------------------------------------
// Build ToolContext from environment variables
// ---------------------------------------------------------------------------

function ensureWorkspace(repo?: string): string {
    const base = process.env.WORKSPACE_BASE || '/workspaces';
    if (!repo) {
        const dir = path.join(base, 'default');
        fs.mkdirSync(dir, { recursive: true });
        return dir;
    }
    if (PROTECTED_GITEA_REPOS.has(repo)) {
        throw new Error(
            `SECURITY: Repo "${repo}" is a protected Vibn platform repo. ` +
            `Agents cannot clone or work in this workspace.`
        );
    }
    const dir = path.join(base, repo.replace('/', '_'));
    const gitea = {
        apiUrl: process.env.GITEA_API_URL || '',
        apiToken: process.env.GITEA_API_TOKEN || '',
        username: process.env.GITEA_USERNAME || ''
    };
    if (!fs.existsSync(path.join(dir, '.git'))) {
        fs.mkdirSync(dir, { recursive: true });
        const authedUrl = `${gitea.apiUrl}/${repo}.git`
            .replace('https://', `https://${gitea.username}:${gitea.apiToken}@`);
        try {
            execSync(`git clone "${authedUrl}" "${dir}"`, { stdio: 'pipe' });
        } catch {
            // Repo may not exist yet — just init
            execSync(`git init`, { cwd: dir, stdio: 'pipe' });
            execSync(`git remote add origin "${authedUrl}"`, { cwd: dir, stdio: 'pipe' });
        }
    }
    return dir;
}

function buildContext(repo?: string): ToolContext {
    const workspaceRoot = ensureWorkspace(repo);

    return {
        workspaceRoot,
        gitea: {
            apiUrl: process.env.GITEA_API_URL || '',
            apiToken: process.env.GITEA_API_TOKEN || '',
            username: process.env.GITEA_USERNAME || ''
        },
        coolify: {
            apiUrl: process.env.COOLIFY_API_URL || '',
            apiToken: process.env.COOLIFY_API_TOKEN || ''
        },
        memoryUpdates: []
    };
}

// ---------------------------------------------------------------------------
// Routes
// ---------------------------------------------------------------------------

// Health check
app.get('/health', (_req: Request, res: Response) => {
    res.json({ status: 'ok', timestamp: new Date().toISOString() });
});

// List available agents
app.get('/api/agents', (_req: Request, res: Response) => {
    const agents = Object.values(AGENTS).map(a => ({
        name: a.name,
        description: a.description,
        tools: a.tools.map(t => t.name)
    }));
    res.json(agents);
});

// Get server status and job statistics
app.get('/api/status', (_req: Request, res: Response) => {
    const allJobs = listJobs(Infinity);
    const total_jobs = allJobs.length;

    const by_status: { [key: string]: number } = {
        queued: 0,
        running: 0,
        completed: 0,
        failed: 0,
    };
    for (const job of allJobs) {
        by_status[job.status] = (by_status[job.status] || 0) + 1;
    }

    const uptime_seconds = Math.floor((new Date().getTime() - startTime.getTime()) / 1000);

    const agents = Object.values(AGENTS).map(a => a.name);

    res.json({
        total_jobs,
        by_status,
        uptime_seconds,
        agents,
    });
});

// Submit a new job
app.post('/api/agent/run', async (req: Request, res: Response) => {
    const { agent: agentName, task, repo } = req.body as { agent?: string; task?: string; repo?: string };

    if (!agentName || !task) {
        res.status(400).json({ error: '"agent" and "task" are required' });
        return;
    }

    const agentConfig = AGENTS[agentName];
    if (!agentConfig) {
        const available = Object.keys(AGENTS).join(', ');
        res.status(400).json({ error: `Unknown agent "${agentName}". Available: ${available}` });
        return;
    }

    const job = createJob(agentName, task, repo);
    res.status(202).json({ jobId: job.id, status: job.status });

    // Run agent asynchronously
    const ctx = buildContext(repo);
    runAgent(job, agentConfig, task, ctx)
        .then(result => {
            updateJob(job.id, {
                status: 'completed',
                result: result.finalText,
                progress: `Done — ${result.turns} turns, ${result.toolCallCount} tool calls`
            });
        })
        .catch(err => {
            updateJob(job.id, {
                status: 'failed',
                error: err instanceof Error ? err.message : String(err),
                progress: 'Agent failed'
            });
        });
});

// Check job status
app.get('/api/jobs/:id', (req: Request, res: Response) => {
    const job = getJob(req.params.id);
    if (!job) {
        res.status(404).json({ error: 'Job not found' });
        return;
    }
    res.json(job);
});

// ---------------------------------------------------------------------------
// Orchestrator — persistent chat with full project context
// ---------------------------------------------------------------------------

app.post('/orchestrator/chat', async (req: Request, res: Response) => {
    const {
        message,
        session_id,
        history,
        knowledge_context
    } = req.body as {
        message?: string;
        session_id?: string;
        history?: LLMMessage[];
        knowledge_context?: string;
    };

    if (!message) { res.status(400).json({ error: '"message" is required' }); return; }

    const sessionId = session_id || `session_${Date.now()}`;
    const ctx = buildContext();

    try {
        const result = await orchestratorChat(sessionId, message, ctx, {
            preloadedHistory: history,
            knowledgeContext: knowledge_context
        });
        res.json(result);
    } catch (err) {
        res.status(500).json({ error: err instanceof Error ? err.message : String(err) });
    }
});

app.get('/orchestrator/sessions', (_req: Request, res: Response) => {
    res.json(listSessions());
});

app.delete('/orchestrator/sessions/:id', (req: Request, res: Response) => {
    clearSession(req.params.id);
    res.json({ cleared: req.params.id });
});

// ---------------------------------------------------------------------------
// Atlas — PRD discovery agent
// ---------------------------------------------------------------------------

app.post('/atlas/chat', async (req: Request, res: Response) => {
    const {
        message,
        session_id,
        history,
        is_init,
    } = req.body as {
        message?: string;
        session_id?: string;
        history?: LLMMessage[];
        is_init?: boolean;
    };

    if (!message) { res.status(400).json({ error: '"message" is required' }); return; }

    const sessionId = session_id || `atlas_${Date.now()}`;
    const ctx = buildContext();

    try {
        const result = await atlasChat(sessionId, message, ctx, {
            preloadedHistory: history,
            isInit: is_init,
        });
        res.json(result);
    } catch (err) {
        res.status(500).json({ error: err instanceof Error ? err.message : String(err) });
    }
});

app.get('/atlas/sessions', (_req: Request, res: Response) => {
    res.json(listAtlasSessions());
});

app.delete('/atlas/sessions/:id', (req: Request, res: Response) => {
    clearAtlasSession(req.params.id);
    res.json({ cleared: req.params.id });
});

// List recent jobs
app.get('/api/jobs', (req: Request, res: Response) => {
    const limit = parseInt((req.query.limit as string) || '20', 10);
    res.json(listJobs(limit));
});

// Gitea webhook endpoint — triggers agent from an issue event
app.post('/webhook/gitea', (req: Request, res: Response) => {
    const event = req.headers['x-gitea-event'] as string;
    const rawBody = req.body as Buffer;

    // Verify HMAC-SHA256 signature
    const webhookSecret = process.env.WEBHOOK_SECRET;
    if (webhookSecret) {
        const sig = req.headers['x-gitea-signature'] as string;
        const expected = crypto
            .createHmac('sha256', webhookSecret)
            .update(rawBody)
            .digest('hex');
        if (!sig || !crypto.timingSafeEqual(Buffer.from(sig), Buffer.from(expected))) {
            res.status(401).json({ error: 'Invalid webhook signature' });
            return;
        }
    }

    const body = JSON.parse(rawBody.toString('utf8'));

    let task: string | null = null;
    let agentName = 'Coder';
    let repo: string | undefined;

    if (event === 'issues' && body.action === 'opened') {
        const issue = body.issue;
        repo = `${body.repository?.owner?.login}/${body.repository?.name}`;
        const labels: string[] = (issue.labels || []).map((l: any) => l.name as string);

        if (labels.includes('agent:pm')) {
            agentName = 'PM';
        } else if (labels.includes('agent:marketing')) {
            agentName = 'Marketing';
        } else if (labels.includes('agent:coder')) {
            agentName = 'Coder';
        } else {
            // No agent label — ignore
            res.json({ ignored: true, reason: 'no agent label on issue' });
            return;
        }

        task = `You have been assigned to resolve a Gitea issue in the repo ${repo}.\n\nIssue #${issue.number}: ${issue.title}\n\nDescription:\n${issue.body || '(no description)'}\n\nWhen done, close the issue by calling gitea_close_issue.`;
    } else if (event === 'push') {
        res.json({ ignored: true, reason: 'push events not auto-processed' });
        return;
    } else {
        res.json({ ignored: true, event });
        return;
    }

    if (!task) {
        res.json({ ignored: true });
        return;
    }

    const agentConfig = AGENTS[agentName];
    const job = createJob(agentName, task, repo);
    res.status(202).json({ jobId: job.id, agent: agentName, event });

    const ctx = buildContext(repo);
    runAgent(job, agentConfig, task, ctx)
        .then(result => {
            updateJob(job.id, {
                status: 'completed',
                result: result.finalText,
                progress: `Done — ${result.turns} turns, ${result.toolCallCount} tool calls`
            });
        })
        .catch(err => {
            updateJob(job.id, {
                status: 'failed',
                error: err instanceof Error ? err.message : String(err),
                progress: 'Agent failed'
            });
        });
});

// ---------------------------------------------------------------------------
// Agent Execute — VIBN Build > Code > Agent tab
//
// Receives a task from the VIBN frontend, runs the Coder agent against
// the project's Gitea repo, and streams progress back to the VIBN DB
// via PATCH /api/projects/[id]/agent/sessions/[sid].
//
// This endpoint returns immediately (202) and runs the agent async so
// the browser can close without killing the loop.
// ---------------------------------------------------------------------------

// Track active sessions for stop support
const activeSessions = new Map<string, { stopped: boolean }>();

app.post('/agent/execute', async (req: Request, res: Response) => {
    const {
        sessionId, projectId, appName, appPath, giteaRepo, task, continueTask,
        autoApprove, coolifyAppUuid,
    } = req.body as {
        sessionId?: string;
        projectId?: string;
        appName?: string;
        appPath?: string;
        giteaRepo?: string;
        task?: string;
        continueTask?: string;
        autoApprove?: boolean;
        coolifyAppUuid?: string;
    };

    if (!sessionId || !projectId || !appPath || !task) {
        res.status(400).json({ error: 'sessionId, projectId, appPath and task are required' });
        return;
    }

    const vibnApiUrl = process.env.VIBN_API_URL ?? 'https://vibnai.com';

    // Register session as active
    const sessionState = { stopped: false };
    activeSessions.set(sessionId, sessionState);

    // Respond immediately — execution is async
    res.status(202).json({ sessionId, status: 'running' });

    // Build workspace context — clone/update the Gitea repo if provided
    let ctx: ReturnType<typeof buildContext>;
    try {
        ctx = buildContext(giteaRepo);
    } catch (err) {
        const msg = err instanceof Error ? err.message : String(err);
        console.error('[agent/execute] buildContext failed:', msg);
        // Notify VIBN DB of failure
        fetch(`${vibnApiUrl}/api/projects/${projectId}/agent/sessions/${sessionId}`, {
            method: 'PATCH',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ status: 'failed', error: msg }),
        }).catch(() => {});
        activeSessions.delete(sessionId);
        return;
    }

    // Capture repo root before scoping to appPath — needed for git commit in auto-approve
    const repoRoot = ctx.workspaceRoot;

    // Scope workspace to the app subdirectory so the agent works there naturally
    if (appPath) {
        const path = require('path') as typeof import('path');
        ctx.workspaceRoot = path.join(ctx.workspaceRoot, appPath);
        const fs = require('fs') as typeof import('fs');
        fs.mkdirSync(ctx.workspaceRoot, { recursive: true });
    }

    const agentConfig = AGENTS['Coder'];
    if (!agentConfig) {
        fetch(`${vibnApiUrl}/api/projects/${projectId}/agent/sessions/${sessionId}`, {
            method: 'PATCH',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ status: 'failed', error: 'Coder agent not registered' }),
        }).catch(() => {});
        activeSessions.delete(sessionId);
        return;
    }

    // If continuing a previous task, combine into a single prompt so the agent
    // understands what was already attempted.
    const effectiveTask = continueTask
        ? `Original task: ${task}\n\nFollow-up instruction: ${continueTask}`
        : task!;

    // Derive the Theia workspace subdir from the giteaRepo slug
    // e.g. "mark/sportsy" → "mark_sportsy", then append appPath
    // So files land at /home/node/workspace/mark_sportsy/apps/admin inside Theia
    const theiaWorkspaceSubdir = giteaRepo
        ? giteaRepo.replace('/', '_')
        : undefined;

    // Run the streaming agent loop (fire and forget)
    runSessionAgent(agentConfig, effectiveTask, ctx, {
        sessionId,
        projectId,
        vibnApiUrl,
        appPath,
        repoRoot,
        isStopped: () => sessionState.stopped,
        autoApprove: autoApprove ?? true,
        giteaRepo,
        coolifyAppUuid,
        coolifyApiUrl: process.env.COOLIFY_API_URL,
        coolifyApiToken: process.env.COOLIFY_API_TOKEN,
        theiaWorkspaceSubdir,
    })
    .catch(err => {
        const msg = err instanceof Error ? err.message : String(err);
        console.error(`[agent/execute] session ${sessionId} crashed:`, msg);
        fetch(`${vibnApiUrl}/api/projects/${projectId}/agent/sessions/${sessionId}`, {
            method: 'PATCH',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ status: 'failed', error: msg }),
        }).catch(() => {});
    })
    .finally(() => {
        activeSessions.delete(sessionId);
    });
});

app.post('/agent/stop', (req: Request, res: Response) => {
    const { sessionId } = req.body as { sessionId?: string };
    if (!sessionId) { res.status(400).json({ error: 'sessionId required' }); return; }

    const session = activeSessions.get(sessionId);
    if (session) {
        session.stopped = true;
        res.json({ ok: true, message: 'Stop signal sent — agent will halt after current step.' });
    } else {
        res.json({ ok: true, message: 'Session not active (may have already completed).' });
    }
});

// ---------------------------------------------------------------------------
// Agent Approve — commit and push agent's changes to Gitea, trigger deploy
//
// Called by vibn-frontend after the user reviews changed files and clicks
// "Approve & commit". The agent runner does git add/commit/push in the
// workspace where the agent was working.
// ---------------------------------------------------------------------------

app.post('/agent/approve', async (req: Request, res: Response) => {
    const { giteaRepo, commitMessage, coolifyApiUrl, coolifyApiToken, coolifyAppUuid } = req.body as {
        giteaRepo?: string;
        commitMessage?: string;
        coolifyApiUrl?: string;
        coolifyApiToken?: string;
        coolifyAppUuid?: string;
    };

    if (!giteaRepo || !commitMessage) {
        res.status(400).json({ error: 'giteaRepo and commitMessage are required' });
        return;
    }

    try {
        // Resolve the workspace root for this repo (does NOT re-clone if already present)
        const workspaceRoot = ensureWorkspace(giteaRepo);

        // Configure git identity for this commit
        const gitea = {
            username: process.env.GITEA_USERNAME || 'agent',
            apiToken: process.env.GITEA_API_TOKEN || '',
            apiUrl: process.env.GITEA_API_URL || '',
        };

        const { execSync: exec } = require('child_process') as typeof import('child_process');
        const gitOpts = { cwd: workspaceRoot, stdio: 'pipe' as const };

        // Ensure git identity
        try {
            exec('git config user.email "agent@vibnai.com"', gitOpts);
            exec('git config user.name "VIBN Agent"', gitOpts);
        } catch { /* already set */ }

        // Stage all changes
        exec('git add -A', gitOpts);

        // Check if there is anything to commit
        let status: string;
        try {
            status = exec('git status --porcelain', gitOpts).toString().trim();
        } catch { status = ''; }

        if (!status) {
            res.json({ ok: true, committed: false, message: 'Nothing to commit — working tree is clean.' });
            return;
        }

        // Commit
        exec(`git commit -m ${JSON.stringify(commitMessage)}`, gitOpts);

        // Push — use token auth embedded in remote URL
        const authedUrl = `${gitea.apiUrl}/${giteaRepo}.git`
            .replace('https://', `https://${gitea.username}:${gitea.apiToken}@`);
        exec(`git push "${authedUrl}" HEAD:main`, gitOpts);

        // Optionally trigger a Coolify redeploy
        let deployed = false;
        if (coolifyApiUrl && coolifyApiToken && coolifyAppUuid) {
            try {
                const deployRes = await fetch(`${coolifyApiUrl}/api/v1/applications/${coolifyAppUuid}/start`, {
                    method: 'POST',
                    headers: { Authorization: `Bearer ${coolifyApiToken}` },
                });
                deployed = deployRes.ok;
            } catch { /* deploy trigger is best-effort */ }
        }

        res.json({ ok: true, committed: true, deployed, message: `Committed and pushed: "${commitMessage}"` });
    } catch (err) {
        const msg = err instanceof Error ? err.message : String(err);
        console.error('[agent/approve]', msg);
        res.status(500).json({ error: msg });
    }
});

// ---------------------------------------------------------------------------
// Generate — thin structured-generation endpoint (no session, no system prompt)
// Use this for one-shot tasks like architecture recommendations.
// ---------------------------------------------------------------------------

app.post('/generate', async (req: Request, res: Response) => {
    const { prompt, model, region } = req.body as { prompt?: string; model?: string; region?: string };
    if (!prompt) { res.status(400).json({ error: '"prompt" is required' }); return; }

    // Allow overriding CLAUDE_REGION per-request for testing
    const prevRegion = process.env.CLAUDE_REGION;
    if (region) process.env.CLAUDE_REGION = region;

    try {
        const llm = createLLM(model ?? 'A', { temperature: 0.3 });
        const messages: import('./llm').LLMMessage[] = [
            { role: 'user', content: prompt }
        ];
        const response = await llm.chat(messages, [], 8192);
        res.json({ reply: response.content ?? '', model: llm.modelId });
    } catch (err) {
        res.status(500).json({ error: err instanceof Error ? err.message : String(err), model });
    } finally {
        if (region) process.env.CLAUDE_REGION = prevRegion ?? '';
    }
});

// ---------------------------------------------------------------------------
// Error handler
// ---------------------------------------------------------------------------

app.use((err: Error, _req: Request, res: Response, _next: NextFunction) => {
    console.error(err.stack);
    res.status(500).json({ error: err.message });
});

// ---------------------------------------------------------------------------
// Start
// ---------------------------------------------------------------------------

app.listen(PORT, () => {
    console.log(`AgentRunner listening on port ${PORT}`);
    console.log(`Agents available: ${Object.keys(AGENTS).join(', ')}`);
    if (!process.env.GOOGLE_API_KEY) {
        console.warn('WARNING: GOOGLE_API_KEY is not set — agents will fail');
    }
    // Theia bridge status
    const theiaContainer = getTheiaContainer();
    if (theiaContainer) {
        console.log(`Theia docker exec: active (container: ${theiaContainer})`);
    } else {
        console.log('Theia docker exec: not available (docker socket not mounted) — using HTTP sync instead');
    }
    isTheiaSyncAvailable().then(ok => {
        console.log(`Theia HTTP sync: ${ok ? 'reachable at ' + (process.env.THEIA_SYNC_URL ?? 'http://theia-code-os:3001') : 'not reachable — sync will be skipped'}`);
    });
});