/*
 * Copyright (C) 2018, 2019 StApps
 * This program is free software: you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation, version 3.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program. If not, see <https://www.gnu.org/licenses/>.
 */
import Ajv from 'ajv';
import {JSONSchema7 as JSONSchema} from 'json-schema';
import {Config, DEFAULT_CONFIG, Definition, SchemaGenerator} from 'ts-json-schema-generator';
import {createFormatter} from 'ts-json-schema-generator';
import {createParser} from 'ts-json-schema-generator';
import {createProgram} from 'ts-json-schema-generator';
import {getTsconfigPath} from './common.js';
import {definitionsOf, lightweightProjectFromPath} from '@openstapps/easy-ast';
import {isSchemaWithDefinitions} from './util/guards.js';
import path from 'path';
import re2 from 're2';

/**
 * StAppsCore converter
 *
 * Converts TypeScript source files to JSON schema files
 */
export class Converter {
  /**
   * Generator instance
   */
  private readonly generator: SchemaGenerator;

  /**
   * Schema validator instance
   */
  private readonly schemaValidator: Ajv.default;

  /**
   * Create a new converter
   * @param projectPath Path to the project
   * @param sourcePath Path to optionally point to a different directory of / or single source file
   */
  constructor(projectPath: string, sourcePath?: string) {
    // set config for schema generator
    const config: Config = {
      ...DEFAULT_CONFIG,
      path: sourcePath,
      sortProps: true,
      topRef: false,
      skipTypeCheck: true,
      tsconfig: path.join(getTsconfigPath(projectPath), 'tsconfig.json'),
      type: 'SC',
    };

    // create TypeScript program from config
    const program = createProgram(config);

    // create generator
    this.generator = new SchemaGenerator(program, createParser(program, config), createFormatter(config));

    // create Ajv instance
    this.schemaValidator = new Ajv.default({code: {regExp: re2 as never}});
  }

  /**
   * Get schema for specific StAppsCore type
   * @param type Type to get the schema for
   * @param version Version to set for the schema
   * @returns Generated schema
   */
  getSchema(type: string, version: string): JSONSchema {
    // generate schema for this file/type
    const schema: JSONSchema = this.generator.createSchema(type);

    // set id of schema
    schema.$id = `https://core.stapps.tu-berlin.de/v${version}/lib/schema/${type}.json`;

    if (isSchemaWithDefinitions(schema)) {
      const selfReference = {
        ...schema,
      };

      delete selfReference.$schema;
      delete selfReference.definitions;
      delete selfReference.$id;

      // add self reference to definitions
      schema.definitions![`SC${type}`] = {
        ...(selfReference as unknown as Definition),
      };
    }

    if (!this.schemaValidator.validateSchema(schema)) {
      throw new Error(`Generated schema for ${type} is invalid!`);
    }

    return schema;
  }
}

/**
 * Get a list of validatable types from an API extractor file
 */
export function getValidatableTypesInPath(path: string): string[] {
  return Object.values(definitionsOf(lightweightProjectFromPath(path)))
    .filter(type => !!type.comment?.tags?.find(it => it.name === 'validatable'))
    .map(type => type.name);
}