const express = require('express');
const router = express.Router();

const config = require('../config');
const runtime = require('../runtime');
const { Job } = require('../job');
const package = require('../package');
const logger = require('logplease').create('api/v2');

router.use((req, res, next) => {
    if (['GET', 'HEAD', 'OPTIONS'].includes(req.method)) {
        return next();
    }

    if (!req.headers['content-type'].startsWith('application/json')) {
        return res.status(415).send({
            message: 'requests must be of type application/json',
        });
    }

    next();
});

router.post('/execute', async (req, res) => {
    const {
        language,
        version,
        files,
        stdin,
        args,
        run_timeout,
        compile_timeout,
        compile_memory_limit,
        run_memory_limit,
    } = req.body;

    if (!language || typeof language !== 'string') {
        return res.status(400).send({
            message: 'language is required as a string',
        });
    }

    if (!version || typeof version !== 'string') {
        return res.status(400).send({
            message: 'version is required as a string',
        });
    }

    if (!files || !Array.isArray(files)) {
        return res.status(400).send({
            message: 'files is required as an array',
        });
    }

    for (const [i, file] of files.entries()) {
        if (typeof file.content !== 'string') {
            return res.status(400).send({
                message: `files[${i}].content is required as a string`,
            });
        }
    }

    if (compile_memory_limit) {
        if (typeof compile_memory_limit !== 'number') {
            return res.status(400).send({
                message: 'if specified, compile_memory_limit must be a number',
            });
        }

        if (
            config.compile_memory_limit >= 0 &&
            (compile_memory_limit > config.compile_memory_limit ||
                compile_memory_limit < 0)
        ) {
            return res.status(400).send({
                message:
                    'compile_memory_limit cannot exceed the configured limit of ' +
                    config.compile_memory_limit,
            });
        }
    }

    if (run_memory_limit) {
        if (typeof run_memory_limit !== 'number') {
            return res.status(400).send({
                message: 'if specified, run_memory_limit must be a number',
            });
        }

        if (
            config.run_memory_limit >= 0 &&
            (run_memory_limit > config.run_memory_limit || run_memory_limit < 0)
        ) {
            return res.status(400).send({
                message:
                    'run_memory_limit cannot exceed the configured limit of ' +
                    config.run_memory_limit,
            });
        }
    }

    const rt = runtime.get_latest_runtime_matching_language_version(
        language,
        version
    );

    if (rt === undefined) {
        return res.status(400).send({
            message: `${language}-${version} runtime is unknown`,
        });
    }

    const job = new Job({
        runtime: rt,
        alias: language,
        files: files,
        args: args || [],
        stdin: stdin || '',
        timeouts: {
            run: run_timeout || 3000,
            compile: compile_timeout || 10000,
        },
        memory_limits: {
            run: run_memory_limit || config.run_memory_limit,
            compile: compile_memory_limit || config.compile_memory_limit,
        },
    });

    await job.prime();

    const result = await job.execute();

    await job.cleanup();

    return res.status(200).send(result);
});

router.get('/runtimes', (req, res) => {
    const runtimes = runtime.map(rt => {
        return {
            language: rt.language,
            version: rt.version.raw,
            aliases: rt.aliases,
            runtime: rt.runtime,
        };
    });

    return res.status(200).send(runtimes);
});

router.get('/packages', async (req, res) => {
    logger.debug('Request to list packages');
    let packages = await package.get_package_list();

    packages = packages.map(pkg => {
        return {
            language: pkg.language,
            language_version: pkg.version.raw,
            installed: pkg.installed,
        };
    });

    return res.status(200).send(packages);
});

router.post('/packages/:language/:version', async (req, res) => {
    logger.debug('Request to install package');

    const { language, version } = req.params;

    const pkg = await package.get_package(language, version);

    if (pkg == null) {
        return res.status(404).send({
            message: `Requested package ${language}-${version} does not exist`,
        });
    }

    try {
        const response = await pkg.install();

        return res.status(200).send(response);
    } catch (e) {
        logger.error(
            `Error while installing package ${pkg.language}-${pkg.version}:`,
            e.message
        );

        return res.status(500).send({
            message: e.message,
        });
    }
});

router.delete('/packages/:language/:version', async (req, res) => {
    logger.debug('Request to uninstall package');

    const { language, version } = req.params;

    const pkg = await package.get_package(language, version);

    if (pkg == null) {
        return res.status(404).send({
            message: `Requested package ${language}-${version} does not exist`,
        });
    }

    try {
        const response = await pkg.uninstall();

        return res.status(200).send(response);
    } catch (e) {
        logger.error(
            `Error while uninstalling package ${pkg.language}-${pkg.version}:`,
            e.message
        );

        return res.status(500).send({
            message: e.message,
        });
    }
});

module.exports = router;