#!/usr/bin/env node

require('require-yaml');
require('colors');
const getopts = require('getopts');
const packageJson = require('./package.json');
const fs = require('fs-extra');
const ini = require('ini');
const path = require('path');
const mysql = require('mysql2/promise');
const nodegit = require('nodegit');
const camelToSnake = require('./lib').camelToSnake;

class MyVC {
    async run(command) {
        console.log(
            'MyVC (MySQL Version Control)'.green,
            `v${packageJson.version}`.magenta
        );

        const usage = {
            description: 'Utility for database versioning',
            params: {
                remote: 'Name of remote to use',
                workspace: 'The base directory of the project',
                socket: 'Wether to connect to database via socket',
                debug: 'Wether to enable debug mode',
                version: 'Display the version number and exit',
                help: 'Display this help message'
            }
        };
        const baseOpts = {
            alias: {
                remote: 'r',
                workspace: 'w'
            },
            boolean: {
                socket: 's',
                debug: 'd',
                version: 'v',
                help: 'h'
            },
            default: {
                workspace: process.cwd()
            }
        };
        const opts = this.getopts(baseOpts);

        try {
            const commandName = opts._[0];
            if (!command && commandName) {
                const commands = [
                    'init',
                    'pull',
                    'push',
                    'version',
                    'dump',
                    'start',
                    'run'
                ];

                if (commands.indexOf(commandName) == -1)
                    throw new Error (`Unknown command '${commandName}'`);
        
                const Klass = require(`./myvc-${commandName}`);
                command = new Klass();
            }

            if (!command) {
                this.showHelp(baseOpts, usage);
                process.exit(0);
            }
    
            const commandOpts = this.getopts(command.localOpts);
            Object.assign(opts, commandOpts);

            const operandToOpt = command.usage.operand;
            if (opts._.length >= 2 && operandToOpt)
                opts[operandToOpt] = opts._[1];
    
            if (opts.version)
                process.exit(0);

            if (opts.help) {
                this.showHelp(command.localOpts, command.usage, commandName);
                process.exit(0);
            }

            // Check version

            let depVersion;
            const versionRegex = /^[^~]?([0-9]+)\.([0-9]+).([0-9]+)$/;
            const wsPackageFile = path.join(opts.workspace, 'package.json');

            if (await fs.pathExists(wsPackageFile)) {
                const wsPackageJson = require(wsPackageFile);
                try {
                    depVersion = wsPackageJson
                        .dependencies
                        .myvc.match(versionRegex);
                } catch (e) {}
            }

            if (depVersion) {
                const myVersion = packageJson.version.match(versionRegex);
                const isSameVersion =
                    depVersion[1] === myVersion[1] &&
                    depVersion[2] === myVersion[2];

                if (!isSameVersion)
                    throw new Error(`This version of MyVC differs from your package.json`)
            }

            // Load method

            parameter('Workspace:', opts.workspace);
            parameter('Remote:', opts.remote || 'local');

            await this.load(opts);
            command.opts = opts;
            await command.run(this, opts);
            await this.unload();
        } catch (err) {
            if (err.name == 'Error' && !opts.debug) {
                console.error('Error:'.gray, err.message.red);
                process.exit(1);
            } else
                throw err;
        }

        function parameter(parameter, value) {
            console.log(parameter.gray, (value || 'null').blue);
        }

        process.exit();
    }

    async load(opts) {
        // Configuration file

        const config = require(`${__dirname}/myvc.default.yml`);
        
        const configFile = 'myvc.config.yml';
        const configPath = path.join(opts.workspace, configFile);
        if (await fs.pathExists(configPath))
            Object.assign(config, require(configPath));

        Object.assign(opts, config);
        opts.configFile = configFile;

        if (!opts.myvcDir)
            opts.myvcDir = path.join(opts.workspace, opts.subdir || '');

        // Database configuration
        
        let iniDir = __dirname;
        let iniFile = 'db.ini';

        if (opts.remote) {
            iniDir = `${opts.myvcDir}/remotes`;
            iniFile = `${opts.remote}.ini`;
        }
        const iniPath = path.join(iniDir, iniFile);
        
        if (!await fs.pathExists(iniPath))
            throw new Error(`Database config file not found: ${iniPath}`);
        
        const iniConfig = ini.parse(await fs.readFile(iniPath, 'utf8')).client;
        const dbConfig = {
            host: iniConfig.host,
            port: iniConfig.port,
            user: iniConfig.user,
            password: iniConfig.password,
            multipleStatements: true,
            authPlugins: {
                mysql_clear_password() {
                    return () => iniConfig.password + '\0';
                }
            }
        };

        if (iniConfig.ssl_ca) {
            dbConfig.ssl = {
                ca: await fs.readFile(`${opts.myvcDir}/${iniConfig.ssl_ca}`),
                rejectUnauthorized: iniConfig.ssl_verify_server_cert != undefined
            }
        }
        if (opts.socket)
            dbConfig.socketPath = '/var/run/mysqld/mysqld.sock';

        Object.assign(opts, {
            iniFile,
            dbConfig
        });
        this.opts = opts;
    }

    async unload() {
        if (this.conn)
            await this.conn.end();
    }

    getopts(opts) {
        const argv = process.argv.slice(2);
        const values = getopts(argv, opts);
        const cleanValues = {};
        for (const opt in values)
            if (opt.length > 1 || opt == '_')
                cleanValues[opt] = values[opt];
        return cleanValues;
    }

    async dbConnect() {
        const {opts} = this;

        if (!this.conn) {
            const conn = this.conn = await this.createConnection();

            const [[schema]] = await conn.query(
                `SHOW DATABASES LIKE ?`, [opts.versionSchema]
            );

            if (!schema)
                await conn.query(`CREATE DATABASE ??`, [opts.versionSchema]);

            const [[res]] = await conn.query(
                `SELECT COUNT(*) > 0 tableExists
                    FROM information_schema.tables
                    WHERE TABLE_SCHEMA = ?
                        AND TABLE_NAME = 'version'`,
                [opts.versionSchema]
            );
    
            if (!res.tableExists) {
                const structure = await fs.readFile(`${__dirname}/structure.sql`, 'utf8');
                await conn.query(structure);
                return null;
            }

            await conn.query(`USE ??`, [opts.versionSchema]);
        }

        return this.conn;
    }

    async createConnection() {
        return await mysql.createConnection(this.opts.dbConfig);
    }

    async fetchDbVersion() {
        const [[version]] = await this.conn.query(
            `SELECT number, gitCommit
                FROM version WHERE code = ?`,
            [this.opts.code]
        );
        return version;
    }

    async changedRoutines(commitSha) {
        const repo = await this.openRepo();
        const changes = [];
        const changesMap = new Map();

        async function pushChanges(diff) {
            if (!diff) return;
            const patches = await diff.patches();

            for (const patch of patches) {
                const path = patch.newFile().path();
                const match = path.match(/^routines\/(.+)\.sql$/);
                if (!match) continue;

                let change = changesMap.get(match[1]);
                if (!change) {
                    change = {path: match[1]};
                    changes.push(change);
                    changesMap.set(match[1], change);
                }
                change.mark = patch.isDeleted() ? '-' : '+';
            }
        }

        const head = await repo.getHeadCommit();

        if (head && commitSha) {
            const commit = await repo.getCommit(commitSha);
            const commitTree = await commit.getTree();

            const headTree = await head.getTree();
            const diff = await headTree.diff(commitTree);
            await pushChanges(diff);
        }

        await pushChanges(await this.getUnstaged(repo));
        await pushChanges(await this.getStaged(repo));

        return changes.sort((a, b) => {
            if (b.mark != a.mark)
                return b.mark == '-' ? 1 : -1;
            return a.path.localeCompare(b.path);
            
        });
    }

    async openRepo() {
        const {opts} = this;

        if (!await fs.pathExists(`${opts.workspace}/.git`))
            throw new Error ('Git not initialized');

        return await nodegit.Repository.open(opts.workspace);
    }

    async getStaged(repo) {
        const head = await repo.getHeadCommit();

        try {
            const emptyTree = '4b825dc642cb6eb9a060e54bf8d69288fbee4904';
            const headTree = await (head
                ? head.getTree()
                : nodegit.Tree.lookup(repo, emptyTree)
            );
            return await nodegit.Diff.treeToIndex(repo, headTree, null);
        } catch (err) {
            console.warn('Cannot fetch staged changes:', err.message);
        }
    }

    async getUnstaged(repo) {
        return await nodegit.Diff.indexToWorkdir(repo, null, {
            flags: nodegit.Diff.OPTION.SHOW_UNTRACKED_CONTENT
                | nodegit.Diff.OPTION.RECURSE_UNTRACKED_DIRS
        });
    }

    async cachedChanges() {
        const dumpDir = `${this.opts.myvcDir}/dump`;
        const dumpChanges = `${dumpDir}/.changes`;

        if (!await fs.pathExists(dumpChanges))
            return null;

        const readline = require('readline');
        const rl = readline.createInterface({
            input: fs.createReadStream(dumpChanges),
            //output: process.stdout,
            console: false
        });

        const changes = [];
        for await (const line of rl) {
            changes.push({
                mark: line.charAt(0),
                path: line.substr(1)
            });
        }
        return changes;
    }

    showHelp(opts, usage, command) {
        const prefix = `${'Usage:'.gray} [npx] myvc`;

        if (command) {
            let log = [prefix, command.blue];
            if (usage.operand) log.push(`[<${usage.operand}>]`);
            if (opts) log.push('[<options>]');
            console.log(log.join(' '))
        } else
            console.log(`${prefix} [<options>] ${'<command>'.blue} [<args>]`);

        if (usage.description)
            console.log(`${'Description:'.gray} ${usage.description}`);

        if (opts) {
            console.log('Options:'.gray);
            this.printOpts(opts, usage, 'alias');
            this.printOpts(opts, usage, 'boolean');
            this.printOpts(opts, usage, 'string');
        }
    }

    printOpts(opts, usage, group) {
        const optGroup = opts[group];
        if (optGroup)
        for (const opt in optGroup) {
            const paramDescription = usage.params[opt] || '';
            let longOpt = opt;
            if (group !== 'boolean') longOpt += ` <string>`;
            longOpt = camelToSnake(longOpt).padEnd(22, ' ')
            console.log(`  -${optGroup[opt]}, --${longOpt} ${paramDescription}`);
        }
    }
}

module.exports = MyVC;

if (require.main === module)
    new MyVC().run();