/*
Copyright 2022 The Matrix.org Foundation C.I.C.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

import * as path from "path";
import * as os from "os";
import * as fse from "fs-extra";

import {dockerRun, dockerStop } from "../docker";

// A plugin that adds command to start & stop dex instances

interface DexConfig {
    configDir: string;
    baseUrl: string;
    port: number;
    host: string;
}

export interface DexInstance extends DexConfig {
    dexId: string;
}

const dexConfigs = new Map<string, DexInstance>();

async function produceConfigWithSynapseURLAdded(): Promise<DexConfig> {
    const templateDir = path.join(__dirname, "template");

    const stats = await fse.stat(templateDir);
    if (!stats?.isDirectory) {
        throw new Error(`Template directory at ${templateDir} not found!`);
    }
    const tempDir = await fse.mkdtemp(path.join(os.tmpdir(), 'hydrogen-testing-dex-'));

    // copy the contents of the template dir, omitting config.yaml as we'll template that
    console.log(`Copy ${templateDir} -> ${tempDir}`);
    await fse.copy(templateDir, tempDir, { filter: f => path.basename(f) !== 'config.yaml' });

    // now copy config.yaml, applying substitutions
    console.log(`Gen ${path.join(templateDir, "config.yaml")}`);
    let hsYaml = await fse.readFile(path.join(templateDir, "config.yaml"), "utf8");
    const synapseHost = process.env.SYNAPSE_IP_ADDRESS;
    const synapsePort = process.env.SYNAPSE_PORT;
    const synapseAddress = `${synapseHost}:${synapsePort}`;
    hsYaml = hsYaml.replace(/{{SYNAPSE_ADDRESS}}/g, synapseAddress);
    const dexHost = process.env.DEX_IP_ADDRESS!;
    const dexPort = parseInt(process.env.DEX_PORT!, 10);
    const dexAddress = `${dexHost}:${dexPort}`;
    hsYaml = hsYaml.replace(/{{DEX_ADDRESS}}/g, dexAddress);
    await fse.writeFile(path.join(tempDir, "config.yaml"), hsYaml);

    const baseUrl = `http://${dexHost}:${dexPort}`;
    return {
        host: dexHost,
        port: dexPort,
        baseUrl,
        configDir: tempDir,
    };
}

export async function dexStart(): Promise<DexInstance> {
    const dexCfg = await produceConfigWithSynapseURLAdded();
    console.log(`Starting dex with config dir ${dexCfg.configDir}...`);
    const dexId = await dockerRun({
        image: "bitnami/dex:latest",
        containerName: "hydrogen-dex",
        dockerParams: [
            "--rm",
            "-v", `${dexCfg.configDir}:/data`,
            `--ip=${dexCfg.host}`,
            "-p", `${dexCfg.port}:5556/tcp`,
            "--network=hydrogen"
        ],
        applicationParams: [
            "serve",
            "data/config.yaml",
        ]
    });

    console.log(`Started dex with id ${dexId} on port ${dexCfg.port}.`);

    const dex: DexInstance = { dexId, ...dexCfg };
    dexConfigs.set(dexId, dex);
    return dex;
}

export async function dexStop(id: string): Promise<void> {
    const dexCfg = dexConfigs.get(id);
    if (!dexCfg) throw new Error("Unknown dex ID");
    await dockerStop({ containerId: id, });
    await fse.remove(dexCfg.configDir);
    dexConfigs.delete(id);
    console.log(`Stopped dex id ${id}.`);
}