class VTepLInterpreter {
    constructor(parser, core) {
        this.parser = parser;
        this.data = [];
        this.content = '';
        this.core = core;
    }

    async render(data) {
        let self = this;
        self.data = data;
        let newData = await self.interpreter(self.parser.parsed);
        self.data = [];
        return newData[0];
    }

    // This stuff is slow as fuck xD Optimize parser to create faster interpreter
    async interpreter(parsed, index = 0) {
        let self = this;
        let types = VParserTypes;
        let tplCont = '';
        for (let i = index; i < parsed.length; i++) {
            let item = parsed[i],
                content = item.content;
            switch (item.type) {
                case types.content:
                    tplCont += content;
                    break;
                case types.variable:
                    tplCont += self.getVariable(content)
                    break;
                case types.assign:
                    let data = content.split("="),
                        key = data.shift();
                    self.setVariable(data.join("=").trim().replace(/"/g, ""), key.trim());
                    break;
                case types.forEach:
                    let d = await this.handleForEach(item, parsed, i);
                    i = d[0];
                    tplCont += d[1];
                    break;
                case types.for:
                    let fd = await this.handleFor(item, parsed, i);
                    i = fd[0];
                    tplCont += fd[1];
                    break;
                case types.if:
                    let id = await this.handleIf(item, parsed, i);
                    i = id[0];
                    tplCont += id[1];
                    break;
                case types.include:
                    tplCont += await this.handleInclude(item);
                    break;
                case types.ifEnd:
                    tplCont += content;
                    return [tplCont, i];
                case types.forEnd:
                    tplCont += content;
                    return [tplCont, i];
                default:
                    console.warn("Invalid Type found");
                    break;
            }
        }
        return [tplCont, parsed.length];
    }

    getVariable(variable, isEqualCheck = false) {
        variable = variable.toString();
        if (!isEqualCheck) {
            let v = variable.split("==");
            if (v.length > 1) {
                return this.getEqual(v[0].trim(), v[1].trim());
            }
            v = variable.split("??");
            if (v.length > 1) {
                return this.getBool(v[0].trim(), v[1].trim());
            }
            v = variable.split("?");
            if (v.length > 1) {
                return this.getIsDefined(v[0].trim(), v[1].trim());
            }
            v = variable.split("||");
            if (v.length > 1) {
                return this.getDefault(v[0].trim(), v[1].trim());
            }
        }
        if (this.data[variable]) {
            return this.data[variable];
        }
        let split = variable.split("."),
            prevVar = this.data;
        for (let i = 0; i < split.length; i++) {
            prevVar = prevVar[split[i]] || prevVar;
        }
        if (typeof prevVar === 'string') {
            return prevVar;
        }
        if (typeof prevVar === 'number') {
            return prevVar.toString();
        }
        if (typeof prevVar === 'boolean') {
            return prevVar.toString();
        }
        return '';
    }

    getEqual(variable1, variable2) {
        let split = variable2.split("?");
        let var1 = this.getVariable(variable1, true);
        let var2 = this.getVariable(split[0].trim(), true);
        if (split.length > 1) {
            let newSplit = split[1].split(":");
            let right = newSplit[1] || '';
            return var1 === var2 ? newSplit[0].trim() : right.trim();
        }
        return var1 === var2 ? 'true' : 'false';
    }

    setVariable(value, variable) {
        let c = this.getVariable(value);
        if (c !== '') {
            value = c;
        }
        this.data[variable] = value;
    }

    async handleForEach(item, parsed, i) {
        let content = item.content.split(" as ");
        let root = this.getVariable(content[0].trim());
        let addTo = 0,
            isInvalid = false;
        if (root === '') {
            isInvalid = true;
            root = {invalid: "true"};
        }
        if (typeof root === 'string') {
            root = JSON.parse(root);
        }
        if (Array.isArray(root) && root.length === 0) {
            root.push("");
            isInvalid = true;
        }
        let d = Object.keys(root),
            raw = '',
            varContent = content[1].trim().split(",");
        for (let x of d) {
            if (varContent.length === 2) {
                this.setVariable(x, varContent[1]);
            }
            this.setVariable(root[x], varContent[0]);
            let data = await this.interpreter(parsed, i + 1);
            addTo = data[1];
            raw += data[0];
        }
        if (isInvalid) {
            raw = '';
        }
        return [addTo, raw];
    }

    async handleInclude(item) {
        let split = item.content.split(";"),
            name = split.shift(),
            data = {};
        await this.core.loadTemplate(name);
        for (let item of split) {
            let d = item.split("="),
                index = d.shift(),
                dat = d.join("=");
            if (!dat.startsWith("\"") && !dat.startsWith("\'")) {
                dat = this.getVariable(dat);
            } else {
                if (dat.startsWith("\"")) {
                    dat = dat.replace(/"/g, "");
                } else {
                    dat = dat.replace(/'/g, "");
                }
            }

            data[index] = dat;
        }
        return await this.core.renderOn(name, data);
    }

    async handleFor(item, parsed, ind) {
        let content = item.content.split(" as "),
            addTo = 0,
            count = content[0].trim().split(".."),
            max = parseInt(count[1]),
            min = parseInt(count[0]),
            newContent = '';
        for (let i = min; i < max; i++) {
            this.setVariable(i.toString(), content[1]);
            let data = await this.interpreter(parsed, ind + 1);
            addTo = data[1];
            newContent += data[0];
        }
        return [addTo, newContent];
    }

    async handleIf(item, parsed, i) {
        let data = await this.interpreter(parsed, i + 1);
        return [data[1], data[0]];
    }

    getIsDefined(variable, value) {
        return this.getVariable(variable, true) !== '' ? value : '';
    }

    getDefault(variable, value) {
        let vars = this.getVariable(variable, true);
        return vars !== '' ? vars : value;
    }

    getBool(variable, value) {
        return this.getVariable(variable, true) ? value : '';
    }
}