import {
  type CollectedApisMap,
  type CollectedEventsMap,
  type Entry,
} from './types';

export const determineEntry = (path: string): Entry => {
  if (path.includes('src/entries/helper')) return 'helper';
  return 'main';
};

/**
 * Generates the API type definitions file content
 */
export function generateApiTypesFile(collectedApis: CollectedApisMap): string {
  let content = `// AUTO-GENERATED FILE. DO NOT EDIT MANUALLY.\n// Generated by: packages/frontend/apps/electron/scripts/generate-types.ts\n/* eslint-disable @typescript-eslint/no-explicit-any */\n\n`;

  content += `// Utility type: remove trailing IpcMainInvokeEvent param and ensure Promise return\n`;
  content += `type EnsurePromise<T> = T extends Promise<any> ? T : Promise<T>;\n`;
  content += `export type ApiMethod<T> = T extends (...args: infer P) => infer R ? (...args: P) => EnsurePromise<R> : never;\n\n`;

  content += `export interface ElectronApis {\n`;

  for (const [scope, methods] of collectedApis) {
    content += `  ${scope}: {\n`;
    for (const method of methods) {
      if (method.description && method.description.trim().length > 0) {
        const lines = method.description.split('\n').map(l => `     * ${l}`);
        content += '    /**\n';
        content += lines.join('\n') + '\n';
        content += '     */\n';
      }
      content += `    ${method.apiMethodName}: ApiMethod<import('${method.modulePath}').${method.className}['${method.methodName}']>;\n`;
    }
    content += `  };\n`;
  }

  content += `}\n`;
  return content;
}

/**
 * Generates the event type definitions file content
 */
export function generateEventTypesFile(
  collectedEvents: CollectedEventsMap
): string {
  let out = `// AUTO-GENERATED FILE. DO NOT EDIT MANUALLY.\n// Generated by: packages/frontend/apps/electron/scripts/generate-types.ts\n/* eslint-disable @typescript-eslint/no-explicit-any */\n\nimport type { Observable } from 'rxjs';\n\n`;

  out += `type ToSubscribe<T extends Observable<unknown>> = T extends Observable<infer P> ? (callback: (payload: P) => void) => () => void : never;\n\n`;

  out += `export interface ElectronEvents {\n`;
  for (const [scope, events] of collectedEvents) {
    out += `  ${scope}: {\n`;
    for (const evt of events) {
      const capName =
        evt.eventName.charAt(0).toUpperCase() + evt.eventName.slice(1);
      if (evt.description && evt.description.trim().length > 0) {
        const lines = evt.description.split('\n').map(l => `     * ${l}`);
        out += '    /**\n';
        out += lines.join('\n') + '\n';
        out += '     */\n';
      }
      out += `    on${capName}: ToSubscribe<import('${evt.modulePath}').${evt.className}['${evt.propertyName}']>;\n`;
    }
    out += `  };\n`;
  }
  out += `}\n`;
  return out;
}

/**
 * Generates a combined metadata file for both IPC handlers and events
 */
export function generateCombinedMetaFile(
  apiHandlers: CollectedApisMap,
  events: CollectedEventsMap
): string {
  let content = `// AUTO-GENERATED FILE. DO NOT EDIT MANUALLY.\n// Generated by: packages/frontend/apps/electron/scripts/generate-types.ts\n/* eslint-disable @typescript-eslint/no-explicit-any */\n`;

  // Build nested structure: entry -> scope -> names[]
  const handlersMeta: Record<string, Record<string, string[]>> = {};
  apiHandlers.forEach((methods, scope) => {
    methods.forEach(m => {
      const ent = m.entry;
      if (!handlersMeta[ent]) handlersMeta[ent] = {};
      if (!handlersMeta[ent][scope]) handlersMeta[ent][scope] = [];
      handlersMeta[ent][scope].push(m.apiMethodName);
    });
  });

  const eventsMeta: Record<string, Record<string, string[]>> = {};
  events.forEach((evtList, scope) => {
    evtList.forEach(e => {
      const ent = e.entry;
      if (!eventsMeta[ent]) eventsMeta[ent] = {};
      if (!eventsMeta[ent][scope]) eventsMeta[ent][scope] = [];
      eventsMeta[ent][scope].push(e.eventName);
    });
  });

  // Serialize handlersMeta & eventsMeta
  content += `export const handlersMeta = ${JSON.stringify(
    handlersMeta,
    null,
    2
  )} as const;\n\n`;
  content += `export const eventsMeta = ${JSON.stringify(eventsMeta, null, 2)} as const;\n`;

  return content;
}