/**
 * Standalone agent harness. Local QVAC inference, sandbox tools, JSONL sessions.
 */

const path = require('path');
const { EventEmitter } = require('events');
const loop = require('./agent/loop.js');
const sessions = require('./agent/sessions.js');
const sandbox = require('./agent/sandbox.js');
const customTools = require('./agent/custom-tools.js');
const mcp = require('./agent/mcp.js');
const engine = require('./lib/qvac.js');
const catalog = require('./lib/catalog.js');

function emitBridge(emitter) {
  return function emit(_kind, payload) {
    const ev = payload || {};
    emitter.emit('event', ev);
    if (ev.type) emitter.emit(ev.type, ev);
  };
}

function wrapSession(summary, opts) {
  const emitter = new EventEmitter();
  const emit = emitBridge(emitter);
  const sessionId = summary.id;

  function on(type, fn) {
    emitter.on(type, fn);
    return () => emitter.off(type, fn);
  }

  async function prompt(text, payload) {
    loop.markLive(sessionId);
    try {
      const session = sessions.load(sessionId);
      const jobId = 'job_' + Date.now().toString(36);
      const merged = Object.assign(
        {
          permissionMode: opts.permissionMode || 'ask',
          webFetch: opts.webFetch === true,
          browser: opts.browser,
          system: opts.system,
          maxTurns: opts.maxTurns,
          maxShellCalls: opts.maxShellCalls,
          maxToolRounds: opts.maxToolRounds,
          voice: opts.voice,
        },
        payload || {}
      );
      return await loop.runTurn({
        session,
        userText: text,
        emit,
        jobId,
        payload: merged,
      });
    } finally {
      loop.finishLive(sessionId);
    }
  }

  async function compact() {
    const session = sessions.load(sessionId);
    const ctxSize = (engine.getLoaded() && engine.getLoaded().ctxSize) || 8192;
    const toolDefs = [];
    const compactOpts = {
      budgetTokens: require('./agent/compaction.js').historyBudget(ctxSize, toolDefs, 0, 0, { voice: !!opts.voice }),
      tools: toolDefs,
      voice: !!opts.voice,
    };
    session.history = opts.voice
      ? require('./agent/compaction.js').compact(session.history, compactOpts)
      : await require('./agent/compaction.js').compactWithLlm(session.history, Object.assign({}, compactOpts, {
      complete: (o) => engine.complete(Object.assign({}, o, { desktopVision: false })),
    }));
    sessions.replaceHistory(sessionId, session.history);
    return session.history;
  }

  return {
    id: sessionId,
    cwd: summary.cwd,
    model: summary.model,
    on,
    prompt,
    compact,
    permit(jobId, toolCallId, decision) {
      const d = decision === true || decision === 'allow' || decision === 'always' ? decision : 'deny';
      loop.resolvePermission(jobId, toolCallId, d === true ? 'allow' : d);
    },
    answer(toolCallId, choice) {
      loop.resolveAsk(null, toolCallId, choice);
    },
    planDecision(decision) {
      loop.resolvePlanDecision(sessionId, decision);
    },
    addTool(tool) {
      customTools.register(sessionId, tool);
      const session = sessions.load(sessionId);
      session.customTools = customTools.list(sessionId);
      sessions.saveSummary(session);
      return session.customTools;
    },
    cancel() {
      loop.cancel(sessionId);
    },
    async dispose() {
      loop.forget(sessionId);
      customTools.clear(sessionId);
      sessions.remove(sessionId);
    },
    load() {
      return sessions.load(sessionId);
    },
  };
}

async function create(opts) {
  opts = opts || {};
  const cwd = path.resolve(opts.cwd || process.cwd());
  const extraRoots = Array.isArray(opts.roots) ? opts.roots.map((r) => path.resolve(r)) : [];
  sandbox.setGrants({ roots: [cwd].concat(extraRoots) });
  const model = opts.model || 'qwen3.5-4b';
  const summary = sessions.create({
    origin: opts.origin || 'local',
    cwd,
    workspace: cwd,
    model,
    title: opts.title || path.basename(cwd),
    hostWorkspace: opts.hostWorkspace !== false,
    builtinTools: opts.builtinTools === false ? false : Array.isArray(opts.builtinTools) ? opts.builtinTools : undefined,
    goal: opts.goal || null,
    planMode: opts.planMode,
    sessionId: opts.sessionId,
  });
  customTools.setSession(summary.id, { hostWorkspace: summary.hostWorkspace });
  if (opts.tools) {
    customTools.register(summary.id, opts.tools);
    summary.customTools = customTools.list(summary.id);
    sessions.saveSummary(summary);
  }
  if (Array.isArray(opts.mcp)) {
    for (const spec of opts.mcp) await mcp.register(spec, opts);
  }
  return wrapSession(summary, opts);
}

function load(sessionId, opts) {
  const summary = sessions.load(sessionId);
  if (summary.cwd) sandbox.setGrants({ roots: [path.resolve(summary.cwd)].concat(opts && opts.roots ? opts.roots : []) });
  if (summary.customTools) customTools.register(summary.id, summary.customTools);
  customTools.setSession(summary.id, { hostWorkspace: summary.hostWorkspace });
  return wrapSession(summary, opts || {});
}

module.exports = {
  create,
  load,
  list: () => sessions.list(),
  catalog: () => catalog.listCatalog(),
  suggest: (hw) => catalog.suggestProfile(hw),
  engine,
  mcp,
  sandbox,
};