const Siteomat = require('@site-o-mat/core')
const fs = require('fs')

/**
 *
 *
 *  
 */
class SiteomatWebpackPlugin {

    constructor(source, views, options = {}) {

        this._source  = source
        this._views   = views
        this._options = options

        if (!fs.existsSync(source)) {
            throw new Error('source "' + source + '" not found!')
        }

        if (!fs.existsSync(views)) {
            throw new Error('views "' + views + '" not found!')
        }
    }

    apply(compiler) {

        const pluginName = SiteomatWebpackPlugin.name

        // webpack module instance can be accessed from the compiler object,
        // this ensures that correct version of the module is used
        // (do not require/import the webpack or any symbols from it directly).
        const { webpack } = compiler

        // Compilation object gives us reference to some useful constants.
        const { Compilation } = webpack

        compiler.hooks.done.tap(pluginName, ({ compilation }) => {

            // if destination is null, use from webpack configuration
            if (!this._options.destination) {
                this._options.destination = compilation.outputOptions.path
            }

            const happySite = new Siteomat(this._source, this._views, this._options)
            happySite.run()
        })
    }
}

module.exports = SiteomatWebpackPlugin