import { Command } from 'commander';
import { init } from './commands/init.js';
import { status } from './commands/status.js';
import { memoryAdd, memorySearch, memoryList } from './commands/memory.js';
import { taskCreate, taskList, taskShow, taskClaim, taskDone } from './commands/task.js';
import { handoffCreate, handoffRead, handoffList } from './commands/handoff.js';
import { decisionCreate, decisionList } from './commands/decision.js';
import { delegate } from './commands/delegate.js';
import { serverStart } from './commands/server.js';
import { loadConfig } from '../core/config.js';
import { remoteClient, RemoteError } from './remoteClient.js';

function getServerUrl(program: Command, cwd: string): string | undefined {
  const flag = (program.opts().server as string | undefined) || process.env.AGENTHUB_SERVER;
  if (flag) return flag;
  try {
    const config = loadConfig(cwd);
    return config.serverUrl;
  } catch {
    return undefined;
  }
}

function remoteOnly(): never {
  console.error('Remote mode is not supported for this command. Run it locally or omit --server.');
  process.exit(1);
}

async function runRemote(serverUrl: string, fn: () => Promise<void>): Promise<void> {
  try {
    await fn();
  } catch (err) {
    if (err instanceof RemoteError) {
      if (err.status === 0) {
        console.error(`AgentHub server at ${serverUrl} is not reachable. Is 'agenthub server start --host 0.0.0.0' running?`);
      } else {
        console.error(`AgentHub server error (${err.status}): ${err.message}`);
      }
      process.exit(1);
    }
    throw err;
  }
}

export function createProgram(cwd: string): Command {
  const program = new Command('agenthub')
    .description('Local coordination layer for AI coding agents')
    .version('0.1.0')
    .option('--server <url>', 'AgentHub server URL (env: AGENTHUB_SERVER)');

  program
    .command('init')
    .description('Initialize AgentHub in the current directory')
    .option('-n, --project-name <name>', 'Project name')
    .option('-y, --yes', 'Use defaults without prompts')
    .option('--server <url>', 'Connect to a remote AgentHub server (stored in config)')
    .action((options) => {
      init(cwd, { ...options, server: options.server || (program.opts().server as string | undefined) });
    });

  program
    .command('status')
    .description('Show project status')
    .option('-u, --update', 'Regenerate status before showing')
    .action(async (options) => {
      const serverUrl = getServerUrl(program, cwd);
      if (serverUrl) {
        await runRemote(serverUrl, async () => {
          const body = options.update ? await remoteClient.updateStatus(serverUrl) : await remoteClient.getStatus(serverUrl);
          console.log(body);
        });
      } else {
        status(cwd, options);
      }
    });

  const memoryCmd = new Command('memory').description('Manage memory entries');
  memoryCmd
    .command('add')
    .description('Add a memory entry')
    .option('--title <title>', 'Title')
    .option('--category <category>', 'Category')
    .option('--content <content>', 'Content')
    .action(async (options) => {
      const serverUrl = getServerUrl(program, cwd);
      if (serverUrl) {
        await runRemote(serverUrl, async () => {
          const memory = await remoteClient.addMemory(serverUrl, options);
          console.log(`Memory saved as ${memory.id}.`);
        });
      } else {
        await memoryAdd(cwd, options);
      }
    });
  memoryCmd
    .command('search <query>')
    .description('Search memory and tasks')
    .action(async (query) => {
      const serverUrl = getServerUrl(program, cwd);
      if (serverUrl) {
        await runRemote(serverUrl, async () => {
          const results = await remoteClient.searchMemory(serverUrl, query);
          if (results.length === 0) { console.log('No results found.'); return; }
          for (const r of results) console.log(`[${r.type}] ${r.id}: ${r.title}`);
        });
      } else {
        memorySearch(cwd, query);
      }
    });
  memoryCmd
    .command('list')
    .description('List memory entries')
    .action(async () => {
      const serverUrl = getServerUrl(program, cwd);
      if (serverUrl) {
        await runRemote(serverUrl, async () => {
          const memories = await remoteClient.listMemory(serverUrl);
          if (memories.length === 0) { console.log('No memory entries found.'); return; }
          for (const m of memories) console.log(`${m.id}: ${m.title}`);
        });
      } else {
        memoryList(cwd);
      }
    });
  program.addCommand(memoryCmd);

  const taskCmd = new Command('task').description('Manage tasks');
  taskCmd
    .command('create')
    .description('Create a task')
    .option('--title <title>', 'Title')
    .option('--role <role>', 'Role')
    .option('--priority <priority>', 'Priority')
    .action(async (options) => {
      const serverUrl = getServerUrl(program, cwd);
      if (serverUrl) {
        await runRemote(serverUrl, async () => {
          const task = await remoteClient.createTask(serverUrl, options);
          console.log(`Created ${task.id}: ${task.title}`);
        });
      } else {
        await taskCreate(cwd, options);
      }
    });
  taskCmd
    .command('list')
    .description('List tasks')
    .option('--status <status>', 'Filter by status')
    .option('--role <role>', 'Filter by role')
    .action(async (options) => {
      const serverUrl = getServerUrl(program, cwd);
      if (serverUrl) {
        await runRemote(serverUrl, async () => {
          const tasks = await remoteClient.listTasks(serverUrl, options);
          if (tasks.length === 0) { console.log('No tasks found.'); return; }
          for (const t of tasks) console.log(`${t.id} [${t.status}] (${t.role ?? 'unassigned'}) ${t.title}`);
        });
      } else {
        taskList(cwd, options);
      }
    });
  taskCmd
    .command('show <id>')
    .description('Show a task')
    .action(async (id) => {
      const serverUrl = getServerUrl(program, cwd);
      if (serverUrl) {
        await runRemote(serverUrl, async () => {
          const { task, body } = await remoteClient.getTask(serverUrl, id);
          console.log(`# ${task.title}`);
          console.log(`Status: ${task.status} | Role: ${task.role ?? '-'} | Priority: ${task.priority}`);
          console.log('\n' + body);
        });
      } else {
        taskShow(cwd, id);
      }
    });
  taskCmd
    .command('claim <id>')
    .description('Claim a task')
    .requiredOption('--agent <agent>', 'Agent name')
    .action(async (id, options) => {
      const serverUrl = getServerUrl(program, cwd);
      if (serverUrl) {
        await runRemote(serverUrl, async () => {
          await remoteClient.claimTask(serverUrl, id, options.agent);
          console.log(`${id} claimed by ${options.agent}.`);
        });
      } else {
        taskClaim(cwd, id, options.agent);
      }
    });
  taskCmd
    .command('done <id>')
    .description('Mark a task as done')
    .action(async (id) => {
      const serverUrl = getServerUrl(program, cwd);
      if (serverUrl) {
        await runRemote(serverUrl, async () => {
          await remoteClient.doneTask(serverUrl, id);
          console.log(`${id} marked as done.`);
        });
      } else {
        taskDone(cwd, id);
      }
    });
  program.addCommand(taskCmd);

  const handoffCmd = new Command('handoff').description('Manage handoffs');
  handoffCmd
    .command('create')
    .description('Create a handoff')
    .option('--fromRole <role>', 'From role')
    .option('--toRole <role>', 'To role')
    .option('--taskId <id>', 'Related task id')
    .option('--summary <summary>', 'Summary')
    .option('--context <context>', 'Context')
    .action(async (options) => {
      const serverUrl = getServerUrl(program, cwd);
      if (serverUrl) {
        await runRemote(serverUrl, async () => {
          const handoff = await remoteClient.createHandoff(serverUrl, options);
          console.log(`Handoff created: ${handoff.id}`);
        });
      } else {
        await handoffCreate(cwd, options);
      }
    });
  handoffCmd
    .command('read <id>')
    .description('Read a handoff')
    .action(async (id) => {
      const serverUrl = getServerUrl(program, cwd);
      if (serverUrl) {
        await runRemote(serverUrl, async () => {
          const { handoff, body } = await remoteClient.getHandoff(serverUrl, id);
          console.log(`# ${handoff.summary}`);
          console.log(`From: ${handoff.fromRole} → ${handoff.toRole}`);
          if (handoff.taskId) console.log(`Task: ${handoff.taskId}`);
          console.log('\n' + body);
        });
      } else {
        handoffRead(cwd, id);
      }
    });
  handoffCmd
    .command('list')
    .description('List handoffs')
    .action(async () => {
      const serverUrl = getServerUrl(program, cwd);
      if (serverUrl) {
        await runRemote(serverUrl, async () => {
          const handoffs = await remoteClient.listHandoffs(serverUrl);
          if (handoffs.length === 0) { console.log('No handoffs found.'); return; }
          for (const h of handoffs) console.log(`${h.id}: ${h.title}`);
        });
      } else {
        handoffList(cwd);
      }
    });
  program.addCommand(handoffCmd);

  const decisionCmd = new Command('decision').description('Manage decisions');
  decisionCmd
    .command('create')
    .description('Create a decision record')
    .option('--title <title>', 'Title')
    .option('--context <context>', 'Context')
    .option('--decision <decision>', 'Decision')
    .action(async (options) => {
      const serverUrl = getServerUrl(program, cwd);
      if (serverUrl) {
        await runRemote(serverUrl, async () => {
          const decision = await remoteClient.createDecision(serverUrl, options);
          console.log(`Decision recorded: ${decision.id}`);
        });
      } else {
        await decisionCreate(cwd, options);
      }
    });
  decisionCmd
    .command('list')
    .description('List decisions')
    .action(async () => {
      const serverUrl = getServerUrl(program, cwd);
      if (serverUrl) {
        await runRemote(serverUrl, async () => {
          const decisions = await remoteClient.listDecisions(serverUrl);
          if (decisions.length === 0) { console.log('No decisions found.'); return; }
          for (const d of decisions) console.log(`${d.id}: ${d.title}`);
        });
      } else {
        decisionList(cwd);
      }
    });
  program.addCommand(decisionCmd);

  program
    .command('delegate')
    .description('Suggest or auto-delegate open tasks')
    .option('--auto', 'Create handoff automatically')
    .action(async (options) => {
      const serverUrl = getServerUrl(program, cwd);
      if (serverUrl) {
        await runRemote(serverUrl, async () => {
          const result = await remoteClient.delegate(serverUrl, options.auto ?? false);
          if (!result.suggestion) { console.log('No open tasks to delegate.'); return; }
          const s = result.suggestion;
          console.log('Suggested delegation:');
          console.log(`  Task: ${s.task.id} — ${s.task.title}`);
          console.log(`  Role: ${s.role}`);
          console.log(`  Preferred agent: ${s.preferredAgent}`);
          if (result.handoff) console.log('Handoff created automatically.');
          else console.log('Run with --auto to create the handoff.');
        });
      } else {
        await delegate(cwd, options);
      }
    });

  const serverCmd = new Command('server').description('Optional local API server');
  serverCmd
    .command('start')
    .description('Start the optional AgentHub API server')
    .option('-p, --port <port>', 'Port', '3377')
    .option('-h, --host <host>', 'Host to bind to', '127.0.0.1')
    .action((options) => serverStart(cwd, { port: parseInt(options.port, 10), host: options.host }));
  program.addCommand(serverCmd);

  return program;
}