const fs = require('fs');
const crypto = require('crypto');
const auth = require('./auth');
const db = require('./db');

// Constante d'erreur
const ERR_REQUEST = 1;
const ERR_AUTH = 2;
const ERR_UNKNOW = 3;
const ERR_TOKEN = 4;
const ERR_SERV = 5;
const ERR_FILE = 6;

// Fonctions de traitement pour les routes
function verifyAuth(req, res, next) {
    if (req.body.user === undefined || req.body.token === undefined) {
        res.json(error(ERR_REQUEST));
        return;
    }
    if (auth.isActivated() && !auth.verify(req.body.user, req.body.token)) {
        res.json(error(ERR_TOKEN));
        return;
    }
    next();
}

function verbose(req, res, next) {
    if (global.verbose) {
        const nbProp = Object.keys(req.body);
        console.log(`\nCall ${req.route.path} with ${nbProp.length} parameter(s)`);
        if (nbProp.length > 0) {
            for (prop in req.body) {
                console.log(`   ${prop}: ${req.body[prop]}`);
            }
        }
    }
    next();
}

// Fonctions reponses
function error(code) {
    let answer = {
        success: false,
        code: code
    };
    switch (code) {
        case ERR_REQUEST:
            answer.message = 'Bad request';
            break;
        case ERR_AUTH:
            answer.message = 'Bad authentication';
            break;
        case ERR_UNKNOW:
            answer.message = 'Unknow user';
            break;
        case ERR_TOKEN:
            answer.message = 'Invalid token';
            break;
        case ERR_SERV:
            answer.message = 'Server error';
            break;
        case ERR_FILE:
            answer.message = 'File not found';
            break;
        default:
            answer.message = 'Unknow error';
    }
    return answer;
}

function success(data) {
    if (data === undefined || data === null) {
        return {success: true};
    } else if (typeof data !== 'object') {
        return {success: true, data: data};
    } else {
        data.success = true;
        return data;
    }
}

// Definition des routes
app.get('/authentication', [verbose, (req, res) => {
    res.json(success({authentication: auth.isActivated()}));
}]);

app.post('/register', [verbose, (req, res) => {
    if (req.body.user === undefined || req.body.password === undefined) {
        res.json(error(ERR_REQUEST));
        return;
    }
    const passHash = auth.passwordHash(req.body.password);
    db.addUser(req.body.user, passHash);
    return res.json(success());
}]);

app.post('/login', [verbose, (req, res) => {
    if (req.body.user === undefined || req.body.password === undefined) {
        res.json(error(ERR_REQUEST));
        return;
    }
    db.getUser(req.body.user).then((user) => {
        if (user === undefined) {
            res.json(error(ERR_UNKNOW));
        } else {
            if (auth.passwordVerify(req.body.password, user.pass)) {
                res.json(success({token: auth.generateToken(req.body.user)}));
            } else {
                res.json(error(ERR_AUTH));
            }
        }
    });
}]);

app.post('/token', [verbose, (req, res) => {
    if (req.body.user === undefined || req.body.token === undefined) {
        res.json(error(ERR_REQUEST));
        return;
    }
    res.json(success({valid: auth.verify(req.body.user, req.body.token)}));
}]);

app.post('/list', [verbose, verifyAuth, (req, res) => {
    db.listFile(req.body.user).then((list) => {
        if (list === false) {
            res.json(error(ERR_SERV));
        } else {
            res.json(success({
                total: list.length,
                list: list
            }));
        }
    });
}]);

app.post('/get/:file', [verbose, verifyAuth, (req, res) => {
    db.getFile(req.body.user, req.params.file).then((file) => {
        // Erreur
        if (file === false) {
            res.json(error(ERR_SERV));
        } else // Le fichier n'existe pas
        if (file === null) {
            res.json(error(ERR_FILE));
        }
        // Création reponse commune
        else {
            let result = {
                fileid: file.fi_hash,
                filename: file.fi_name
            };
            // Recupération données fichier
            if (global.storage === 'database') {
                result.data = file.data;
                res.json(success(result));
            } else {
                if (!fs.existsSync(file.data)) {
                    res.json(error(ERR_FILE));
                }
                fs.readFile(file.data, (err, data) => {
                    result.data = data.toString();
                    res.json(success(result));
                });
            }
        }
    });
}]);

app.post('/save/:file', [verbose, verifyAuth, (req, res) => {
    //Si on sauvegarde les données dans des fichiers, generation du chemin
    let data = req.body.data;
    if (global.storage === 'file') {
        let hash = Date.now() + '-' + req.body.user + '-' + req.params.file;
        hash = crypto.createHash('md5').update(hash).digest('base64');
        hash = hash.replace(/=/g, '');
        data = './data/' + hash + '.fdata';
    }
    let promise = db.addFile(req.body.user, req.params.file, data);
    if (promise === false) {
        res.json(error(ERR_SERV));
    }
    promise.then((fileId) => {
        if (fileId === false) {
            res.json(ERR_SERV);
        } else {
            // Si en mode fichier stockage dans un fichier
            if ((global.storage === 'file')) {
                fs.writeFile(data, req.body.data, (err) => {
                    if (err) {
                        if (global.verbose) {
                            console.error(err);
                        }
                        res.json(error(ERR_SERV));
                    } else {
                        res.json(success({fileId: fileId, fileName: req.params.file}));
                    }
                });
            }
            // Le fichier est directement sauvegarder en base
            else {
                res.json(success({fileId: fileId, fileName: req.params.file}));
            }
        }
    });
}]);

/*
app.get('/', function (req, res) {
    res.send('Hello World!');
});

app.get('/test/:val?', function (req, res) {
    res.send('Val = ' + req.params.val);
});

app.get(/.*aze$/, function (req, res) {
    res.send('URL end with aze');
})
*/