/*
 * 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 {asyncPool} from '@krlwlfrt/async-pool/lib/async-pool';
import {Logger} from '@openstapps/logger';
import {OpenAPIV3} from 'openapi-types';
import {basename, dirname, join} from 'path';
import {ProjectReflection} from 'typedoc';
import {Type} from 'typedoc/dist/lib/models';
import {capitalize, NodeWithMetaInformation, RouteWithMetaInformation} from './common';

/**
 * Gather relevant information of routes
 *
 * This gathers the information for all routes that implement the abstract class SCAbstractRoute.
 * Furthermore it instantiates every route and adds it to the information.
 *
 * @param reflection Contents of the JSON representation which Typedoc generates
 */
export async function gatherRouteInformation(reflection: ProjectReflection): Promise<RouteWithMetaInformation[]> {
  const routes: RouteWithMetaInformation[] = [];

  if (!Array.isArray(reflection.children)) {
    throw new Error('Project reflection doesn\'t contain any modules.');
  }

  // tslint:disable-next-line:no-magic-numbers
  await asyncPool(2, reflection.children, async (module) => {
    if (Array.isArray(module.children) && module.children.length > 0) {
      // tslint:disable-next-line:no-magic-numbers
      await asyncPool(2, module.children, (async (node) => {
        if (Array.isArray(node.extendedTypes) && node.extendedTypes.length > 0) {
          if (node.extendedTypes.some((extendedType) => {
            // tslint:disable-next-line:completed-docs
            return (extendedType as (Type & { name: string; })).name === 'SCAbstractRoute';
          })) {
            Logger.info(`Found ${node.name} in ${module.originalName}.`);

            if (Array.isArray(module.originalName.match(/\.d\.ts$/))) {
              module.originalName = join(dirname(module.originalName), basename(module.originalName, '.d.ts'));
              Logger.info(`Using compiled version of module in ${module.originalName}.`);
            }

            const importedModule = await import(module.originalName);

            const route = new importedModule[node.name]();

            // tslint:disable-next-line: no-any
            const errors = route.errorNames.map((error: any) => {
              const scError = new importedModule[error.name]();
              scError.name = error.name;

              return scError;
            });

            route.responseBodyDescription = module.children!.find(element => element.name === route.responseBodyName)?.comment?.shortText;
            route.requestBodyDescription = module.children!.find(element => element.name === route.requestBodyName)?.comment?.shortText;

            route.errors = errors;

            routes.push({description: node.comment!, name: node.name, route});
          }
        }
      }));
    }
  });

  if (routes.length === 0) {
    throw new Error('No route information found.');
  }

  return routes;
}

/**
 * Get link for a node
 *
 * @param name Name of the node
 * @param node Node itself
 */
export function getLinkForNode(name: string, node: NodeWithMetaInformation): string {
  let link = 'https://openstapps.gitlab.io/core/';
  const module = node.module
    .toLowerCase()
    .split('/')
    .join('_');

  if (node.type === 'Type alias') {
    link += 'modules/';
    link += `_${module}_`;
    link += `.html#${name.toLowerCase()}`;

    return link;
  }

  let type = 'classes';
  if (node.type !== 'Class') {
    type = `${node.type.toLowerCase()}s`;
  }

  link += `${type}/`;
  link += `_${module}_`;
  link += `.${name.toLowerCase()}.html`;

  return link;
}

/**
 * Generate documentation snippet for one route
 *
 * @param routeWithInfo A route instance with its meta information
 * @param outDirSchemasPath Path to directory that will contain relevant schemas for the route
 * @param schemasToCopy Schemas identified as relevant for this route
 * @param tagsToKeep Tags / keywords that can be used for grouping routes
 */
 export function generateOpenAPIForRoute(routeWithInfo: RouteWithMetaInformation,
                                     outDirSchemasPath: string,
                                         schemasToCopy: string[],
                                            tagsToKeep: string[]): OpenAPIV3.PathItemObject {
  const route = routeWithInfo.route;
  const path: OpenAPIV3.PathItemObject = {};

  schemasToCopy.push(route.requestBodyName, route.responseBodyName);

  path[(route.method.toLowerCase() as OpenAPIV3.HttpMethods)] = {
    summary: capitalize(routeWithInfo.description.shortText?.replace(/(Route to |Route for )/gmi, '')),
    description: routeWithInfo.description.text,
    requestBody: {
      description: route.responseBodyDescription ?? undefined,
      content: {
        'application/json': {
          schema: {
            $ref: join(outDirSchemasPath, `${route.requestBodyName}.json`),
          },
        },
      },
    },
    parameters: [{
      name: 'X-StApps-Version',
      in: 'header',
      schema: {
        type: 'string',
        example: '2.0.0',
      },
      required: true,
    }],
    responses: {},
    tags: routeWithInfo.tags?.filter(value => tagsToKeep.includes(value)),
  };

  path[(route.method.toLowerCase() as OpenAPIV3.HttpMethods)]!.responses![route.statusCodeSuccess] = {
    description: route.responseBodyDescription,
    content: {
      'application/json': {
        schema: {
          $ref: join(outDirSchemasPath, `${route.responseBodyName}.json`),
        },
      },
    },
  };

  route.errors.forEach(error => {
    schemasToCopy.push(error.name);
    path[(route.method.toLowerCase() as OpenAPIV3.HttpMethods)]!.responses![error.statusCode] = {
      description: error.message ?? capitalize(error.name.replace(/([A-Z][a-z])/g,' $1')
        .replace('SC ', '')),
      content: {
        'application/json': {
          schema: {
            $ref: join(outDirSchemasPath, `${error.name}.json`),
          },
        },
      },
    };
  });

  if (typeof route.obligatoryParameters === 'object') {
    for (const [parameter, schemaDefinition] of Object.entries(route.obligatoryParameters)) {
      const openapiParam: OpenAPIV3.ParameterObject = {
        in: 'path',
        name: parameter,
        required: true,
        schema: {
          // TODO make this less of a hack and search copied schemas for the first occurring definition
          $ref: `schemas/SCSearchResponse.json#/definitions/${schemaDefinition}`,
        },
      };
      path[(route.method.toLowerCase() as OpenAPIV3.HttpMethods)]?.parameters?.push(openapiParam);
    }
  }

  return path;
}