const Handlebars = require('handlebars');
const fs = require('../../core/fs');
let utils = require('../../utils/utils.js');


Handlebars.registerHelper('capitalize', function(word) {
    return word.charAt(0).toUpperCase() + word.slice(1);
});

Handlebars.registerHelper('ifview', function(stateMutability, options) {
    let result = stateMutability === 'view' || stateMutability === 'pure' || stateMutability === 'constant';
    if (result) {
        return options.fn(this);
    } 
    return options.inverse(this);
});

Handlebars.registerHelper('ifeq', function(elem, value, options){
    if (elem === value) {
        return options.fn(this);
    }
    return options.inverse(this);
});

Handlebars.registerHelper('iflengthgt', function(arr, val, options) {
    if (arr.length > val) {
        return options.fn(this);
    }    
    return options.inverse(this);
});

Handlebars.registerHelper('emptyname', function(name, index) {
    return name ? name : 'output' + index;
});


Handlebars.registerHelper('methodname', function(abiDefinition, functionName, inputs){
    let funCount = abiDefinition.filter(x => x.name === functionName).length;
    if(funCount === 1){
        return '.' + functionName;
    }
    return new Handlebars.SafeString(`['${functionName}(${inputs !== null ? inputs.map(input => input.type).join(',') : ''})']`);
});

class ScaffoldingReact {
    constructor(embark, options){
        this.embark = embark;
        this.options = options;
        this.embark.registerDappGenerator('react', this.build.bind(this));
    }

    _generateFile(contract, templateFilename, extension, data, overwrite){
        const filename = contract.className.toLowerCase() + '.' + extension;
        const filePath = './app/' + filename;
        if (!overwrite && fs.existsSync(filePath)){
            throw new Error("file '" + filePath + "' already exists");
        }

        const templatePath = fs.embarkPath('lib/modules/scaffolding-react/templates/' + templateFilename);
        const source = fs.readFileSync(templatePath).toString();
        const template = Handlebars.compile(source);

        // Write template
        const result = template(data);
        fs.writeFileSync(filePath, result);
    }

    build(contract, overwrite, cb){
        const packageInstallCmd = 'npm install react react-bootstrap react-dom';
        utils.runCmd(packageInstallCmd, null, (err) => {
            if (err) {
                this.embark.logger.error(err.message);
                process.exit(1);
            }

            try {
                const filename = contract.className.toLowerCase();

                this._generateFile(contract, 'index.html.tpl', 'html',
                {
                    'title': contract.className, 
                    filename
                }, overwrite);
        
                this._generateFile(contract, 'dapp.js.tpl', 'js',         
                {
                    'title': contract.className,
                    'contractName': contract.className,
                    'functions': contract.abiDefinition.filter(x => x.type === 'function')
                }, overwrite);
        
                // Update config
                const contents = fs.readFileSync("./embark.json");
                let embarkJson = JSON.parse(contents);
                embarkJson.app["js/" + filename + ".js"] = "app/" + filename + '.js';
                embarkJson.app[filename + ".html"] = "app/" + filename + '.html';
        
                fs.writeFileSync("./embark.json", JSON.stringify(embarkJson, null, 4));
        
                this.embark.logger.info(filename + ".html generated");
                this.embark.logger.info(filename + ".js generated");
                 
            } catch(error){
                this.embark.logger.error(error.message);
                process.exit(1);
            }
            cb();
        });
    }
}

module.exports = ScaffoldingReact;