const fs = require('fs-extra');
const sharp = require('sharp');
const path = require('path');

module.exports = Self => {
    Self.getPath = function() {
        return '/var/lib/salix/image';
    };

    Self.registerImage = async(collectionName, file, srcFilePath) => {
        const models = Self.app.models;
        const tx = await Self.beginTransaction({});
        const myOptions = {transaction: tx};

        try {
            const collection = await models.ImageCollection.findOne({
                fields: [
                    'id',
                    'name',
                    'maxWidth',
                    'maxHeight',
                    'model',
                    'property'
                ],
                where: {name: collectionName},
                include: {
                    relation: 'sizes',
                    scope: {
                        fields: ['width', 'height', 'crop']
                    }
                }
            }, myOptions);

            const fileName = file.split('.')[0];
            const rootPath = Self.getPath();
            const data = {
                name: fileName,
                collectionFk: collectionName
            };

            const newImage = await Self.upsertWithWhere(data, {
                name: fileName,
                collectionFk: collectionName,
                updated: (new Date).getTime()
            }, myOptions);

            // Resizes and saves the image
            const collectionDir = path.join(rootPath, collectionName);
            const dstDir = path.join(collectionDir, 'full');
            const dstFile = path.join(dstDir, file);

            const resizeOpts = {
                withoutEnlargement: true,
                fit: 'inside'
            };

            await fs.mkdir(dstDir, {recursive: true});
            await sharp(srcFilePath, {failOnError: false})
                .resize(collection.maxWidth, collection.maxHeight, resizeOpts)
                .png()
                .toFile(dstFile);

            const sizes = collection.sizes();
            for (let size of sizes) {
                const dstDir = path.join(collectionDir, `${size.width}x${size.height}`);
                const dstFile = path.join(dstDir, file);
                const resizeOpts = {
                    withoutEnlargement: true,
                    fit: size.crop ? 'cover' : 'inside'
                };

                await fs.mkdir(dstDir, {recursive: true});
                await sharp(srcFilePath, {failOnError: false})
                    .resize(size.width, size.height, resizeOpts)
                    .png()
                    .toFile(dstFile);
            }

            const model = models[collection.model];

            if (!model)
                throw new Error('Matching model not found');

            const item = await model.findById(fileName, null, myOptions);
            if (item) {
                await item.updateAttribute(
                    collection.property,
                    fileName,
                    myOptions
                );
            }

            if (fs.existsSync(srcFilePath))
                await fs.unlink(srcFilePath);

            await tx.commit();
            return newImage;
        } catch (e) {
            await tx.rollback();
            throw e;
        }
    };
};