import { join } from 'node:path';
import type { Subprocess } from 'bun';
import type { PiEvent } from '../../api/pi/types';
import type { ClaudeSpawnParams, ClaudeSpawnStreamingParams, ClaudeCodeResult } from '../protocol';
import { buildSandboxPrefix, buildRunuserSuffix, SANDBOX_HOME } from '../sandbox';
import { setClaudeSession, clearClaudeSession, getClaudeSession } from './state';
import { parseStream } from './stream-parser';

const SEND_TIMEOUT_MS = 5 * 60 * 1000;

// Resolve absolute path to claude binary
const CLAUDE_BIN = (() => {
  const result = Bun.spawnSync({ cmd: ['which', 'claude'], stdout: 'pipe', stderr: 'ignore' });
  return result.stdout.toString().trim() || 'claude';
})();

const DATA_PATH = process.env.DATA_PATH ?? join(process.cwd(), 'data');

// Build full bwrap sandbox args for Claude (prefix + Anthropic env + runuser suffix)
function buildSandboxArgs(email: string): string[] {
  const prefix = buildSandboxPrefix(email);

  // Claude-specific env vars
  if (process.env.ANTHROPIC_BASE_URL) prefix.push('--setenv', 'ANTHROPIC_BASE_URL', process.env.ANTHROPIC_BASE_URL);
  if (process.env.ANTHROPIC_API_KEY) prefix.push('--setenv', 'ANTHROPIC_API_KEY', process.env.ANTHROPIC_API_KEY);

  return [...prefix, ...buildRunuserSuffix()];
}

// Active streaming processes
const activeProcs = new Map<string, Subprocess>();

// MCP config path, set by user-instance at startup
let mcpConfigPath: string | undefined;

export function setMcpConfigPath(path: string): void {
  mcpConfigPath = path;
}

// ── Blocking send ──

type ClaudeCodeOutput = {
  result: string;
  session_id: string;
  cost_usd: number;
  input_tokens: number;
  output_tokens: number;
  is_error: boolean;
};

export async function spawnClaude(params: ClaudeSpawnParams): Promise<ClaudeCodeResult> {
  const { prompt, sessionKey, email } = params;

  const existingSession = getClaudeSession(sessionKey);

  const claudeArgs = [
    CLAUDE_BIN,
    '-p',
    prompt,
    '--dangerously-skip-permissions',
    '--output-format',
    'json',
  ];

  if (mcpConfigPath) claudeArgs.push('--mcp-config', mcpConfigPath);

  const subModel = params.model?.split('/')[1];
  if (subModel) claudeArgs.push('--model', subModel);

  if (existingSession) {
    claudeArgs.push('--resume', existingSession);
  }

  const isSuperAdmin = params.role === 'Super Admin';
  const spawnCmd = isSuperAdmin ? claudeArgs : [...buildSandboxArgs(email), ...claudeArgs];
  const spawnCwd = isSuperAdmin ? (process.env.HOME ?? join(DATA_PATH, email, 'home')) : undefined;

  const proc = Bun.spawn(spawnCmd, {
    stdin: 'pipe',
    stdout: 'pipe',
    stderr: 'pipe',
    cwd: spawnCwd,
    env: process.env as Record<string, string>,
  });

  const timeout = setTimeout(() => {
    try {
      proc.kill();
    } catch {
      /* already dead */
    }
  }, SEND_TIMEOUT_MS);

  try {
    const [stdout, stderr] = await Promise.all([new Response(proc.stdout).text(), new Response(proc.stderr).text()]);
    const exitCode = await proc.exited;
    clearTimeout(timeout);

    if (exitCode !== 0 && !stdout.trim()) {
      throw new Error(`claude exited with code ${exitCode}: ${stderr.trim().slice(0, 200)}`);
    }

    let output: ClaudeCodeOutput;
    try {
      output = JSON.parse(stdout) as ClaudeCodeOutput;
    } catch {
      return {
        text: stdout.trim() || '(no response)',
        sessionId: sessionKey,
        model: 'claude-code',
        cost: { inputTokens: 0, outputTokens: 0, totalUSD: 0 },
      };
    }

    if (output.is_error) {
      throw new Error(output.result || 'Claude Code returned an error');
    }

    if (output.session_id) {
      setClaudeSession(sessionKey, output.session_id);
    }

    return {
      text: output.result || '(no response)',
      sessionId: sessionKey,
      model: 'claude-code',
      cost: {
        inputTokens: output.input_tokens ?? 0,
        outputTokens: output.output_tokens ?? 0,
        totalUSD: output.cost_usd ?? 0,
      },
    };
  } catch (err) {
    clearTimeout(timeout);
    throw err;
  }
}

// ── Streaming send ──

export async function spawnClaudeStreaming(
  params: ClaudeSpawnStreamingParams,
  onEvent: (event: PiEvent) => void,
): Promise<void> {
  const { prompt, sessionKey, email } = params;

  const existingSession = getClaudeSession(sessionKey);

  const claudeArgs = [
    CLAUDE_BIN,
    '-p',
    prompt,
    '--dangerously-skip-permissions',
    '--output-format',
    'stream-json',
    '--verbose',
    '--include-partial-messages',
  ];

  if (mcpConfigPath) claudeArgs.push('--mcp-config', mcpConfigPath);

  const subModel = params.model?.split('/')[1];
  if (subModel) claudeArgs.push('--model', subModel);

  if (existingSession) {
    claudeArgs.push('--resume', existingSession);
  }

  const { CLAUDECODE: _, ...cleanEnv } = process.env;
  const isSuperAdmin = params.role === 'Super Admin';
  const spawnCmd = isSuperAdmin ? claudeArgs : [...buildSandboxArgs(email), ...claudeArgs];
  const spawnCwd = isSuperAdmin ? (process.env.HOME ?? join(DATA_PATH, email, 'home')) : undefined;

  const proc = Bun.spawn(spawnCmd, {
    stdin: 'ignore',
    stdout: 'pipe',
    stderr: 'pipe',
    cwd: spawnCwd,
    env: cleanEnv as Record<string, string>,
  });

  activeProcs.set(sessionKey, proc);

  const timeout = setTimeout(() => {
    try {
      proc.kill();
    } catch {
      /* already dead */
    }
    onEvent({ type: 'error', message: 'Claude Code timed out after 5 minutes' });
  }, SEND_TIMEOUT_MS);

  // Process NDJSON stream
  try {
    const stdout = proc.stdout as ReadableStream<Uint8Array>;
    const callbacks = {
      onEvent,
      onSessionId: (sessionId: string) => setClaudeSession(sessionKey, sessionId),
    };

    const state = await parseStream(stdout, callbacks);

    clearTimeout(timeout);

    if (!state.gotResult) {
      const exitCode = await proc.exited;
      const stderr = await new Response(proc.stderr as ReadableStream<Uint8Array>).text();
      if (state.textBuffer) {
        onEvent({ type: 'text', text: state.textBuffer });
      }
      if (exitCode !== 0) {
        onEvent({ type: 'error', message: `Claude Code exited with code ${exitCode}: ${stderr.trim().slice(0, 200)}` });
      } else {
        onEvent({ type: 'result', cost: { inputTokens: 0, outputTokens: 0, totalUSD: 0 } });
      }
    }
  } catch (err) {
    clearTimeout(timeout);
    onEvent({ type: 'error', message: String(err) });
  } finally {
    activeProcs.delete(sessionKey);
  }
}

export function killClaudeSession(sessionKey: string): boolean {
  const proc = activeProcs.get(sessionKey);
  if (proc) {
    try {
      proc.kill();
    } catch {
      /* already dead */
    }
    activeProcs.delete(sessionKey);
    return true;
  }
  return false;
}

export function clearSession(sessionKey: string): void {
  clearClaudeSession(sessionKey);
}

export function getActiveSessionKeys(): string[] {
  return Array.from(activeProcs.keys());
}