import { parse as parseJsonc } from 'jsonc-parser';
import { pathToFileURL } from 'node:url';
import {
  OPENCHAMBER_AGENT_TOOL_ACTION_DEFINITIONS,
  OPENCHAMBER_AGENT_TOOL_ACTIONS,
} from '../openchamber-control/actions.js';

const TOOL_SCHEMA_VERSION = 1;
const ACTIONS = new Set(OPENCHAMBER_AGENT_TOOL_ACTIONS);
const AGENT_TOOL_ACTION_TITLES = Object.fromEntries(
  OPENCHAMBER_AGENT_TOOL_ACTION_DEFINITIONS.map(({ action, title }) => [action, title]),
);

const PLUGIN_PARAMETER_PROPERTIES = {
  projectId: { type: 'string', description: 'Configured project ID; do not combine with directory' },
  directory: { type: 'string', description: 'Absolute checkout or session directory; defaults to the current session directory' },
  sessionId: { type: 'string' },
  messageId: { type: 'string', description: 'Optional fork boundary message ID' },
  taskId: { type: 'string' },
  title: { type: 'string' },
  prompt: { type: 'string' },
  model: { type: 'string', description: 'Model in provider/model format. When the user names no model: for session.create pick a suitable one from models.list favorites or recents (omit if there are none); for send and fork omit it — the session reuses its previous model' },
  agent: { type: 'string', description: 'OpenCode agent name; new sessions default to the build agent and existing sessions keep their previous one. Set only when the user explicitly requests a different agent' },
  variant: { type: 'string', description: 'Model variant; use only when the user explicitly requests it' },
  worktree: { type: 'string', description: 'New worktree name for session.create. Omit by default; use only when the user explicitly asks for an isolated worktree. Uncommitted changes do not carry over into a new worktree' },
  branch: { type: 'string', description: 'Branch name for the new worktree' },
  startRef: { type: 'string', description: 'Git ref used to create the new worktree' },
  setUpstream: { type: 'boolean', description: 'Make the new worktree branch track its upstream' },
  goal: { type: 'boolean', description: 'Run the dispatched prompt in Goal Mode; use only when the user explicitly requests it' },
  goalTokenBudget: { type: 'integer', minimum: 1000, maximum: 100_000_000, description: 'Goal token budget; requires goal' },
  wait: { type: 'boolean', description: 'Wait for current session activity to become idle. Omit by default; use only when the user asks or the next step requires the completed result' },
  timeout: { type: 'integer', minimum: 1, maximum: 86_400, description: 'Wait timeout in seconds (default 600); requires wait' },
  lastAssistant: { type: 'boolean', description: 'Return the last assistant text; create/send/fork require wait' },
  limit: { type: 'integer', minimum: 1, description: 'Maximum sessions or messages to return (default 10)' },
  all: { type: 'boolean', description: 'Include archived sessions or all messages, depending on the action' },
  last: { type: 'boolean', description: 'Return only the last matching session message' },
  withStatus: { type: 'boolean', description: 'Include authoritative status in session.list' },
  role: { type: 'string', enum: ['all', 'user', 'assistant'], description: 'Message role filter' },
  name: { type: 'string' },
  daily: { type: 'string', description: 'Daily run time in HH:mm format' },
  weekly: { type: 'string', description: 'Comma-separated weekdays; 0=Sunday and 6=Saturday' },
  once: { type: 'string', description: 'One-time run date in YYYY-MM-DD format' },
  time: { type: 'string', description: 'Weekly or one-time run time in HH:mm format' },
  cron: { type: 'string', description: 'Cron expression' },
  timezone: { type: 'string', description: 'IANA timezone' },
  disabled: { type: 'boolean', description: 'true disables and false enables; required for schedule.toggle' },
};

const asNonEmptyString = (value) => {
  if (typeof value !== 'string') return null;
  const trimmed = value.trim();
  return trimmed.length > 0 ? trimmed : null;
};

const createResult = ({ ok, action, data, error, exitCode }) => ({
  schemaVersion: TOOL_SCHEMA_VERSION,
  ok,
  action: action || 'unknown',
  ...(data !== undefined ? { data } : {}),
  ...(error ? { error } : {}),
  ...(Number.isInteger(exitCode) ? { exitCode } : {}),
});

const isLoopbackAddress = (value) => {
  const address = typeof value === 'string' ? value.toLowerCase() : '';
  return address === '127.0.0.1'
    || address === '::1'
    || address === '::ffff:127.0.0.1';
};

const createPluginSource = () => String.raw`
export const OpenChamberPlugin = async () => ({
  tool: {
    openchamber: {
      description: "Control OpenChamber projects, sessions, and scheduled tasks on the user's behalf. Sessions and scheduled tasks you create are for the user to follow and interact with; never use this tool to delegate parts of your own current task. Use one action per call. Scope with projectId or directory; omit both to use the current session directory. Session dispatches return immediately by default and you receive no notification when a dispatched session finishes, so never promise to report back on it; the user follows it in OpenChamber; a dispatched session needs no follow-up from you. If the user later asks how it went, use session.messages (add wait to block until it is idle, lastAssistant for just the final answer) — session.send always sends a NEW prompt and never just waits. Set wait only when the user asks or the next step requires the completed result. Session and worktree deletion are unavailable.",
      args: {
        action: { type: "string", enum: ${JSON.stringify(OPENCHAMBER_AGENT_TOOL_ACTIONS)}, oneOf: ${JSON.stringify(OPENCHAMBER_AGENT_TOOL_ACTION_DEFINITIONS.map(({ action, description }) => ({ const: action, description })))}, description: "OpenChamber action to perform" },
        parameters: { type: "object", properties: ${JSON.stringify(PLUGIN_PARAMETER_PROPERTIES)}, additionalProperties: false, description: "Inputs for the action; use an empty object when none are needed" },
      },
      async execute(input, context) {
        const args = { ...(input.parameters ?? {}), action: input.action }
        const actionTitles = ${JSON.stringify(AGENT_TOOL_ACTION_TITLES)}
        const title = Object.hasOwn(actionTitles, args.action) ? actionTitles[args.action] : args.action
        context.metadata({
          title,
          metadata: {
            openchamber: {
              schemaVersion: ${TOOL_SCHEMA_VERSION},
              action: args.action,
              description: title,
            },
          },
        })
        const endpoint = process.env.OPENCHAMBER_AGENT_TOOL_URL
        const token = process.env.OPENCHAMBER_AGENT_TOOL_TOKEN
        const failure = (payload) => ({
          title,
          output: JSON.stringify(payload),
          metadata: { openchamber: { schemaVersion: ${TOOL_SCHEMA_VERSION}, action: args.action, description: title, ok: false } },
        })
        if (!endpoint || !token) {
          return failure({ schemaVersion: ${TOOL_SCHEMA_VERSION}, ok: false, action: args.action, error: { message: "OpenChamber managed tool connection is unavailable" } })
        }

        try {
          const response = await fetch(endpoint, {
            method: "POST",
            headers: {
              authorization: "Bearer " + token,
              "content-type": "application/json",
            },
            body: JSON.stringify({ input: args, contextDirectory: context.directory }),
            signal: context.abort,
          })
          const output = await response.text()
          let result = null
          try { result = JSON.parse(output) } catch {}
          const valid = result?.schemaVersion === ${TOOL_SCHEMA_VERSION} && typeof result?.ok === "boolean" && typeof result?.action === "string"
          context.metadata({
            title,
            metadata: {
              openchamber: {
                schemaVersion: ${TOOL_SCHEMA_VERSION},
                action: args.action,
                description: title,
                ok: valid && result.ok === true,
              },
            },
          })
          if (valid) return { title, output, metadata: { openchamber: { schemaVersion: ${TOOL_SCHEMA_VERSION}, action: args.action, description: title, ok: result.ok === true } } }
          return failure({ schemaVersion: ${TOOL_SCHEMA_VERSION}, ok: false, action: args.action, error: { message: "OpenChamber returned an invalid response", kind: "runtime", status: response.status } })
        } catch (error) {
          if (context.abort.aborted) throw error
          return failure({ schemaVersion: ${TOOL_SCHEMA_VERSION}, ok: false, action: args.action, error: { message: error instanceof Error ? error.message : String(error), kind: "runtime" } })
        }
      },
    },
  },
})
`;

const mergePluginConfig = (rawConfig, pluginUrl) => {
  const errors = [];
  const parsed = asNonEmptyString(rawConfig) ? parseJsonc(rawConfig, errors, { allowTrailingComma: true }) : {};
  if (errors.length > 0 || !parsed || typeof parsed !== 'object' || Array.isArray(parsed)) {
    throw new Error('OPENCODE_CONFIG_CONTENT must contain a valid JSON object before OpenChamber can inject its managed tool');
  }
  if (parsed.plugin !== undefined && !Array.isArray(parsed.plugin)) {
    throw new Error('OPENCODE_CONFIG_CONTENT plugin must be an array before OpenChamber can inject its managed tool');
  }
  const configured = Array.isArray(parsed.plugin) ? parsed.plugin : [];
  parsed.plugin = [
    ...configured.filter((value) => value !== pluginUrl && (!Array.isArray(value) || value[0] !== pluginUrl)),
    pluginUrl,
  ];
  return JSON.stringify(parsed);
};

export const createAgentToolRuntime = (dependencies) => {
  const {
    crypto,
    fsPromises,
    path,
    dataDir,
    getActivePort,
    executeAction,
    env = process.env,
  } = dependencies;
  const pluginDirectory = path.join(dataDir, 'agent-tool');
  const pluginPath = path.join(pluginDirectory, 'openchamber-plugin.js');
  let activeToken = null;

  const prepareManagedOpenCodeEnv = async () => {
    const port = getActivePort();
    if (!Number.isInteger(port) || port <= 0) {
      throw new Error('OpenChamber listener port is unavailable for managed tool injection');
    }
    await fsPromises.mkdir(pluginDirectory, { recursive: true });
    await fsPromises.writeFile(pluginPath, createPluginSource(), { mode: 0o600 });
    activeToken = crypto.randomBytes(32).toString('base64url');
    const pluginUrl = pathToFileURL(pluginPath).href;
    return {
      OPENCODE_CONFIG_CONTENT: mergePluginConfig(env.OPENCODE_CONFIG_CONTENT, pluginUrl),
      OPENCHAMBER_AGENT_TOOL_URL: `http://127.0.0.1:${port}/api/openchamber/agent-tool`,
      OPENCHAMBER_AGENT_TOOL_TOKEN: activeToken,
    };
  };

  const authorize = (req) => {
    if (!activeToken || !isLoopbackAddress(req.socket?.remoteAddress)) return false;
    const header = asNonEmptyString(req.headers?.authorization);
    if (!header?.startsWith('Bearer ')) return false;
    const provided = Buffer.from(header.slice(7));
    const expected = Buffer.from(activeToken);
    return provided.length === expected.length && crypto.timingSafeEqual(provided, expected);
  };

  const execute = async (payload = {}, options = {}) => {
    const action = asNonEmptyString(payload.input?.action);
    if (!action || !ACTIONS.has(action)) {
      return createResult({ ok: false, action, error: { message: `Unsupported OpenChamber action: ${action || 'missing'}`, kind: 'usage' } });
    }
    if (typeof executeAction !== 'function') {
      return createResult({ ok: false, action, error: { message: 'OpenChamber control service is unavailable', kind: 'runtime' } });
    }
    try {
      const data = await executeAction(action, payload.input, payload.contextDirectory, options);
      return createResult({ ok: true, action, data });
    } catch (error) {
      return createResult({
        ok: false,
        action,
        ...(error?.partial === true ? { data: {
          partial: true,
          partialAction: error.partialAction,
          sessionId: error.sessionId,
          directory: error.directory,
        } } : {}),
        error: {
          message: error instanceof Error ? error.message : String(error),
          kind: Number(error?.statusCode) >= 400 && Number(error?.statusCode) < 499 ? 'usage' : 'runtime',
        },
      });
    }
  };

  const registerRoutes = (app, express) => {
    app.post('/api/openchamber/agent-tool', express.json({ limit: '1mb' }), async (req, res) => {
      if (!authorize(req)) return res.status(401).json({ error: 'Unauthorized' });
      const controller = new AbortController();
      const abortOnDisconnect = () => {
        if (!res.writableEnded) controller.abort();
      };
      req.once('aborted', abortOnDisconnect);
      res.once('close', abortOnDisconnect);
      try {
        return res.json(await execute(req.body, { signal: controller.signal }));
      } catch (error) {
        return res.json(createResult({
          ok: false,
          action: req.body?.input?.action,
          error: { message: error instanceof Error ? error.message : String(error), kind: 'runtime' },
        }));
      } finally {
        req.off('aborted', abortOnDisconnect);
        res.off('close', abortOnDisconnect);
      }
    });
  };

  return {
    prepareManagedOpenCodeEnv,
    registerRoutes,
    execute,
  };
};