export class ConsoleInput {
    constructor(inputElem, console, codeRunner) {
        this.inputElem = inputElem;
        this.console = console;
        this.codeRunner = codeRunner;
        this.history = [];
        this.historyIndex = 0;

        this.inputElem.onkeydown = (ev) => this.onKeyDown(ev);
    }

    onKeyDown(ev) {
        switch (ev.key) {
            case "Enter":
                this.submit();
                break;
            case "ArrowUp":
                this.moveHistory(-1);
                ev.preventDefault();
                break;
            case "ArrowDown":
                this.moveHistory(1);
                ev.preventDefault();
                break;
            case "l":
                if (ev.ctrlKey) {
                    this.console.clear();
                    ev.preventDefault();
                }
                break;
        }
    }

    submit() {
        const code = this.inputElem.value;
        this.inputElem.value = "";

        this.console.addInput(code);

        this.history.push(code);
        this.historyIndex = this.history.length;

        this.codeRunner.evaluateCode(code);
    }

    moveHistory(delta) {
        this.historyIndex += delta;

        if (this.historyIndex < 0) {
            this.historyIndex = 0;
            return;
        }

        if (this.historyIndex >= this.history.length) {
            this.historyIndex = this.history.length;
            this.inputElem.value = "";
            return;
        }

        this.inputElem.value = this.history[this.historyIndex];
        this.inputElem.setSelectionRange(
            this.inputElem.value.length,
            this.inputElem.value.length,
        );
    }
}