import manifest from "../../python-runtime/manifest.json" with { type: "json" };
import { fnv1a64 } from "./replay.mjs";

export const PYTHON_BRIDGE_SCHEMA = "python-worker-bridge.v1";

function clone(value) { return structuredClone(value); }
function finiteJson(value) {
  if (value === null || typeof value !== "object") return true;
  if (typeof value === "number") return Number.isFinite(value);
  return Array.isArray(value) ? value.every(finiteJson) : Object.values(value).every(finiteJson);
}

export class PythonBridge {
  constructor({ loadPyodide = globalThis.loadPyodide, maxSourceBytes = 65536, maxCalls = 256 } = {}) {
    this.loadPyodide = loadPyodide;
    this.maxSourceBytes = maxSourceBytes;
    this.maxCalls = maxCalls;
    this.pyodide = null;
    this.initialized = false;
    this.state = { imports: [], calls: [], errors: [], capabilities: [], tick: 0 };
  }

  capabilities() {
    return {
      schema: PYTHON_BRIDGE_SCHEMA,
      runtime: manifest.runtime,
      version: manifest.version,
      python_version: manifest.python_version,
      abi_version: manifest.abi_version,
      platform: manifest.platform,
      worker_only: manifest.worker_only,
      virtual_modules: clone(manifest.virtual_modules),
      denied_capabilities: [...manifest.denied_capabilities],
      initialized: this.initialized,
    };
  }

  async initialize() {
    if (this.initialized) return { status: "verified", capabilities: this.capabilities() };
    if (typeof this.loadPyodide !== "function") return this.fail("python_runtime_unavailable", "python.runtime_unavailable");
    try {
      this.pyodide = await this.loadPyodide({ indexURL: manifest.index_url });
      this.initialized = true;
      return { status: "verified", capabilities: this.capabilities() };
    } catch (error) {
      return this.fail("python_runtime_init", String(error?.message ?? error));
    }
  }

  importModule(module) {
    const symbols = manifest.virtual_modules[module];
    if (!symbols) return this.fail("python_unsupported_module", "python.unsupported_module", { module });
    if (!this.state.imports.includes(module)) this.state.imports.push(module);
    return { status: "verified", module, symbols: [...symbols], state_hash: this.hash() };
  }

  checkCapability(capability) {
    if (manifest.denied_capabilities.includes(capability)) return this.fail("real_hardware_excluded", "python.host_capability_denied", { capability, status: "REAL-EXCLUDED" });
    if (typeof capability !== "string" || capability.length === 0) return this.fail("python_capability_invalid", "python.capability_invalid");
    if (!this.state.capabilities.includes(capability)) this.state.capabilities.push(capability);
    return { status: "verified", capability, state_hash: this.hash() };
  }

  invoke(module, symbol, args = []) {
    const symbols = manifest.virtual_modules[module];
    if (!symbols || !symbols.includes(symbol)) return this.fail("python_symbol_unsupported", "python.symbol_unsupported", { module, symbol });
    if (!Array.isArray(args) || !finiteJson(args)) return this.fail("python_argument_invalid", "python.argument_invalid");
    if (this.state.calls.length >= this.maxCalls) return this.fail("python_call_limit", "python.call_limit");
    if (!this.state.imports.includes(module)) this.state.imports.push(module);
    const call = { module, symbol, args: clone(args), tick: this.state.tick };
    this.state.calls.push(call);
    return { status: "verified", value: { module, symbol, args: clone(args) }, state_hash: this.hash() };
  }

  async execute(source) {
    if (typeof source !== "string" || new TextEncoder().encode(source).length > this.maxSourceBytes) return this.fail("python_source_limit", "python.source_limit");
    const denied = manifest.denied_capabilities.find((capability) => new RegExp(`(?:^|[^A-Za-z0-9_])${capability.replaceAll(".", "\\.")}(?:$|[^A-Za-z0-9_])`).test(source));
    if (denied) return this.fail("real_hardware_excluded", "python.host_capability_denied", { capability: denied, status: "REAL-EXCLUDED" });
    if (!this.pyodide || typeof this.pyodide.runPythonAsync !== "function") return this.fail("python_runtime_unavailable", "python.runtime_unavailable");
    try {
      const value = await this.pyodide.runPythonAsync(source);
      return { status: "verified", value: value === undefined ? null : value, state_hash: this.hash() };
    } catch (error) {
      return this.fail("python_exception", "python.exception", { detail: String(error?.message ?? error) });
    }
  }

  fail(code, message_key, extra = {}) {
    this.state.errors.push({ code, tick: this.state.tick });
    return { status: extra.status ?? "blocked", code, message_key, retryable: false, ...extra, state_hash: this.hash() };
  }

  setTick(tick) { if (Number.isSafeInteger(tick) && tick >= 0) this.state.tick = tick; }
  exportState() { return { schema: PYTHON_BRIDGE_SCHEMA, initialized: this.initialized, state: clone(this.state) }; }
  restoreState(value) {
    if (!value || value.schema !== PYTHON_BRIDGE_SCHEMA || !value.state) return this.fail("python_state_invalid", "python.state_invalid");
    this.initialized = Boolean(value.initialized);
    this.state = clone(value.state);
    return { status: "verified", state_hash: this.hash() };
  }
  hash() { return fnv1a64(this.state); }
}

export { manifest };