import { promises as fs } from 'fs';
import Ajv, { type ErrorObject, type JSONSchemaType } from 'ajv';

import type { Config } from '../types';

export const validateSchema = (config: {}): Promise<Config> => {
  const configSchema: JSONSchemaType<Config> = {
    type: 'object',
    properties: {
      ios: {
        type: 'object',
        properties: {
          workspace: { type: 'string', nullable: true },
          configuration: { type: 'string', nullable: true, default: 'Debug' },
          scheme: { type: 'string', nullable: true },
          buildCommand: { type: 'string', nullable: true },
          binaryPath: { type: 'string', nullable: true },
          device: { type: 'string' },
          quiet: { type: 'boolean', nullable: true },
        },
        required: ['device'],
        anyOf: [
          { required: ['workspace', 'scheme'] },
          { required: ['buildCommand', 'binaryPath'] },
        ],
        nullable: true,
        additionalProperties: false,
      },
      android: {
        type: 'object',
        properties: {
          packageName: { type: 'string' },
          buildCommand: { type: 'string', nullable: true },
          buildType: { type: 'string', nullable: true, default: 'Release' },
          binaryPath: { type: 'string', nullable: true },
          quiet: { type: 'boolean', nullable: true },
        },
        required: ['packageName'],
        anyOf: [{ required: [] }, { required: ['buildCommand', 'binaryPath'] }],
        nullable: true,
        additionalProperties: false,
      },
      debug: { type: 'boolean', nullable: true, default: false },
      report: { type: 'boolean', nullable: true, default: true },
    },
    required: [],
    anyOf: [{ required: ['ios'] }, { required: ['android'] }],
    additionalProperties: false,
  };

  const ajv = new Ajv({ useDefaults: true });
  const validate = ajv.compile(configSchema);

  return new Promise((resolve, reject) => {
    if (validate(config)) {
      resolve(config);
    } else {
      const errorMessage = validate
        .errors!.map((err: ErrorObject) => `${err.schemaPath}: ${err.message}`)
        .join(' ');
      reject(errorMessage);
    }
  });
};

export const readConfigFile = async (configPath: string) => {
  try {
    const configData = await fs.readFile(configPath, 'binary');
    const configString = Buffer.from(configData).toString();
    const parsedConfig = JSON.parse(configString);
    return parsedConfig;
  } catch (err) {
    throw new Error(
      `Could not load the config at ${configPath}. For an example see https://formidable.com/open-source/react-native-owl/docs/introduction/config-file/`
    );
  }
};

export const getConfig = async (configPath: string): Promise<Config> => {
  const config = await readConfigFile(configPath);
  return await validateSchema(config);
};