import { IConfig, IHash, Component, Config } from "merapi";
import { ICompile, IHelper } from "interfaces/main";
import * as path from "path";
import * as fs from "fs";
import * as yaml from "js-yaml";

export default class Compile extends Component implements ICompile {
    private directives : any = {
        include(file : string, basepath : string, helper : IHelper) {
            const ext = path.extname(file);
            if (ext === ".yml" || ext === ".yaml") {
                return helper.loadYaml(path.resolve(basepath, file));
            } else if (ext === ".json")  {
                return require(path.resolve(basepath, file));
            } else {
                return fs.readFileSync(path.resolve(basepath, file)).toString();
            }
        }
    };

    constructor(private helper : IHelper) {
        super();
    }

    public execDirective(name : string, directive : any, dict : IHash<any>, basepath : string) {
        for (const i in dict) {
            if (typeof dict[i] !== "string") {
                continue;
            }
            const val = dict[i].trim();
            if (val.indexOf("$" + name + "(") === 0 && val.charAt(val.length - 1) === ")") {
                dict[i] = directive(dict[i].substring(2 + name.length, dict[i].length - 1), basepath, this.helper);
            }
        }
    }

    public execDirectives(config : IConfig, basepath : string) : IConfig {
        const flattened = config.flatten();
        for (const i in this.directives) {
            if (i) {
                this.execDirective(i, this.directives[i], flattened, basepath);
            }
        }
        return config.create(flattened);
    }
}