const c = require('chalk');
const emoji = require('node-emoji');

/**
 * Coverage tool output handler. This is where any logging solidity-coverage does on its
 * own behalf is managed. NB, most output is generated by the host dev stack (e.g. truffle,
 * buidler or by the coverage generator (e.g. Istanbul).
 * )
 */
class UI {
  constructor(log){
    this.log = log || console.log;
  }

  /**
   * Writes a formatted message to console
   * @param  {String}   kind  message selector
   * @param  {String[]} args  info to inject into template
   */
  report(kind, args=[]){
    const ct = c.bold.green('>');
    const ds = c.bold.yellow('>');

    const kinds = {
      'vm-fail': `:warning:  ${c.red('There was a problem attaching to the ganache-core VM.')} `+
                            `${c.red('Check the provider option syntax in solidity-coverage docs.')}\n`+
                 `:warning:  ${c.red('Using ganache-core-sc (eq. core v2.7.0) instead.')}\n`,

      'truffle-help': `Usage: truffle run coverage [options]\n\n` +
                      `Options:\n` +
                      `  --file:       path (or glob) to run subset of JS test files\n` +
                      `  --solcoverjs: relative path to .solcover.js (ex: ./../.solcover.js)\n`,

      'truffle-version': `${ct} ${c.bold('truffle')}:      v${args[0]}`,
      'ganache-version': `${ct} ${c.bold('ganache-core')}: ${args[0]}`,

      'instr-start': `\n${c.bold('Instrumenting for coverage...')}` +
                     `\n${c.bold('=============================')}\n`,

      'instr-skip':  `\n${c.bold('Coverage skipped for:')}` +
                     `\n${c.bold('=====================')}\n`,

      'instr-item':    `${ct} ${args[0]}`,
      'instr-skipped': `${ds} ${c.grey(args[0])}`,
    }

    this.log(emoji.emojify(kinds[kind]));
  }

  /**
   * Returns a formatted message. Useful for error message.
   * @param  {String}   kind  message selector
   * @param  {String[]} args  info to inject into template
   * @return {String}         message
   */
  generate(kind, args){

  }
}

module.exports = UI;