import express, { Request, Response, NextFunction } from "express";
import fileUpload, { UploadedFile } from "express-fileupload";
import path from "path";
import fs from "fs";
import { JobManager, runGhostscript, createJobId } from "./jobs";
import type { context, options } from "./jobs";


const app = express()
const jobManager = new JobManager()

app.set('view engine', 'ejs');
app.use(express.static(path.join(__dirname, 'static')));
app.use(fileUpload())

app.get('/', (req: Request, res: Response) => {
    res.render('index')
})

app.post('/new_job', (req: Request, res: Response) => {
    try {
        const jobId = createJobId();
        const file = req.files?.file as UploadedFile;
        // Ensure file was uploaded and is of correct type
        if (!file) {
            return res.status(400).render("upload_err", {code: 400})
        }
        if (file.mimetype !== 'application/pdf') {
            return res.status(415).render("upload_err", {code: 415})
        }

        // Write file to disk
        const filePath = `./uploads/${jobId}/in.pdf`;
        fs.mkdirSync(`./uploads/${jobId}`, { recursive: true });
        file.mv(filePath, (err) => {
            if (err) {
                throw err;
            }

        const quality: string = req.body.quality;
        const opts: options = { quality };
        const ctx: context = { jobManager, jobId, filePath };
        runGhostscript(ctx, opts);
        res.render('processing', { job_id: jobId });
    });
} catch (error) {
    if (error)
    console.error(error);
    res.status(500).send('Internal Server Error');
}
});

app.get('/job_state', (req: Request, res: Response) => {
    const job_id: string = req.query.job_id as string;
    if (!job_id) {
        res.status(400).send("Missing job ID")
    }
    const jobStatus = jobManager.get_job_status(job_id);

    // If job doesn't exist, return 404
    if (Object.keys(jobStatus).length === 0) {
        res.status(404).send('Job not found');
        return;
    }

    // Send job status as JSON response
    res.json(jobStatus);
})

app.get('/download', (req: Request, res: Response) => {
    try{
        const jobId = req.query.job_id as string;
    if (!jobId) {
        res.status(400).send("Missing job ID")
    }
    const jobStatus = jobManager.get_job_status(jobId);
    if (Object.keys(jobStatus).length === 0) {
        res.status(404).send('Job not found, files expire after 10 minutes');
        return;
    }

    const filePath = path.join('.', 'uploads', `${jobId}`, `out.pdf`);
    console.log("Download Request: ", filePath)
    if (fs.existsSync(filePath)) {
        // Set the appropriate headers for the PDF file
        res.setHeader('Content-Type', 'application/pdf');
        res.setHeader('Content-Disposition', `attachment; filename=SpeedyF-output.pdf`);

        // Create a read stream to the PDF file and pipe it to the response
        const stream = fs.createReadStream(filePath);
        stream.pipe(res);
    } else {
        // If the file doesn't exist, return a 404 Not Found response
        res.status(404).send('File not found');
    }
} catch (error) {
    // If an error occurs, return a 500 Internal Server Error response
    console.error('An error occurred:', error);
    res.status(500).send('Internal Server Error');
}

});

const port = process.env.PORT || 3000;
app.listen(port, () => {
    console.log(`Server listening on port ${port}`)
})