/**
 * Orbital-Befehle: Eingabe (Halte-Taste + Richtungsfolge), Abklingzeiten,
 * Bodenmarkierung und verzögerter Einschlag.
 *
 * Die Eingabelogik steckt in `logic/comboInput.js`, die Abklingzeiten in
 * `logic/cooldowns.js`; hier wird beides mit Phaser-Tastatur und Grafik verbunden.
 * @module systems/OrbitalSystem
 */

import { COLORS, GAME, ORBITAL } from '../config.js';
import { codeToDirection, ComboInput } from '../logic/comboInput.js';
import { CooldownTracker } from '../logic/cooldowns.js';
import { clamp, distance } from '../logic/math.js';
import { GroundMarker } from './GroundMarker.js';
import { oncePerEvent } from './keyboard.js';

/** Farbe der Markierung je Befehl. */
const MARKER_COLORS = Object.freeze({
  strike: COLORS.strike,
  supply: COLORS.supply,
  turret: COLORS.turret,
});

/**
 * @typedef {typeof ORBITAL.commands[number]} OrbitalCommand
 */

/**
 * @typedef {Object} OrbitalCallbacks
 * @property {() => {x: number, y: number}} getPlayer
 * @property {() => {x: number, y: number}} getAimPoint  Mausposition in Weltkoordinaten.
 * @property {(command: OrbitalCommand, x: number, y: number) => void} onImpact
 * @property {(kind: 'step'|'fail'|'deploy'|'notReady', command?: OrbitalCommand, remainingMs?: number) => void} onFeedback
 */

export class OrbitalSystem {
  /**
   * @param {Phaser.Scene} scene
   * @param {OrbitalCallbacks} callbacks
   */
  constructor(scene, callbacks) {
    this.scene = scene;
    this.callbacks = callbacks;
    this.commands = ORBITAL.commands;
    this.combo = new ComboInput(this.commands);
    this.cooldowns = new CooldownTracker();
    /** @type {{command: OrbitalCommand, marker: GroundMarker}[]} */
    this.pending = [];
    this.now = 0;

    this.holdKey = scene.input.keyboard.addKey(ORBITAL.holdKey);
    // Pfeiltasten abfangen, sonst scrollt der Browser die Seite.
    scene.input.keyboard.addCapture('UP,DOWN,LEFT,RIGHT');
    this.onKeyDown = oncePerEvent((event) => this.handleKeyDown(event));
    scene.input.keyboard.on('keydown', this.onKeyDown);
  }

  /** @returns {boolean} true, solange ein Befehl eingegeben wird (Bewegung pausiert). */
  get isInputActive() {
    return this.combo.active;
  }

  /**
   * @param {number} now Spielzeit in ms.
   */
  update(now) {
    this.now = now;
    if (this.holdKey.isDown && !this.combo.active) this.combo.begin();
    else if (!this.holdKey.isDown && this.combo.active) this.combo.end();

    for (let i = this.pending.length - 1; i >= 0; i -= 1) {
      const entry = this.pending[i];
      if (entry.marker.isDue(now)) {
        entry.marker.destroy();
        this.pending.splice(i, 1);
        this.callbacks.onImpact(entry.command, entry.marker.x, entry.marker.y);
      } else {
        entry.marker.update(now);
      }
    }
  }

  /**
   * @param {KeyboardEvent} event
   * @private
   */
  handleKeyDown(event) {
    // Gedrückt gehaltene Tasten erzeugen Wiederholungen – die zählen nicht als Eingabe.
    if (event.repeat) return;
    // Q und erste Richtung können im selben Frame ankommen, bevor update() die
    // Eingabe gestartet hat – dann hier starten, sonst ginge die erste Richtung verloren.
    if (!this.combo.active && this.holdKey.isDown) this.combo.begin();
    if (!this.combo.active) return;
    const direction = codeToDirection(event.code);
    if (!direction) return;
    const result = this.combo.push(direction);
    if (result.status === 'progress') this.callbacks.onFeedback('step');
    else if (result.status === 'fail') this.callbacks.onFeedback('fail');
    else if (result.status === 'match') this.request(/** @type {string} */ (result.commandId));
  }

  /**
   * Fordert einen Befehl an (sofern bereit) und setzt die Markierung ans Ziel.
   * @param {string} commandId
   * @returns {boolean}
   */
  request(commandId) {
    const command = this.commands.find((c) => c.id === commandId);
    if (!command) return false;
    const now = this.now;
    if (!this.cooldowns.isReady(command.id, now)) {
      this.callbacks.onFeedback('notReady', command, this.cooldowns.remaining(command.id, now));
      return false;
    }
    const target = this.clampTarget(this.callbacks.getAimPoint());
    this.cooldowns.trigger(command.id, command.cooldownMs, now);
    const marker = new GroundMarker(
      this.scene,
      target.x,
      target.y,
      command.radius,
      MARKER_COLORS[command.id] ?? COLORS.gold,
      now,
      now + command.delayMs,
      { label: command.shortName, beam: true },
    );
    marker.update(now);
    this.pending.push({ command, marker });
    this.callbacks.onFeedback('deploy', command);
    return true;
  }

  /**
   * Begrenzt das Ziel auf die maximale Reichweite und die Arena.
   * @param {{x: number, y: number}} aim
   * @returns {{x: number, y: number}}
   */
  clampTarget(aim) {
    const player = this.callbacks.getPlayer();
    const d = distance(player, aim);
    let { x, y } = aim;
    if (d > ORBITAL.maxTargetRange) {
      const f = ORBITAL.maxTargetRange / d;
      x = player.x + (aim.x - player.x) * f;
      y = player.y + (aim.y - player.y) * f;
    }
    const margin = GAME.spawnMargin;
    return {
      x: clamp(x, margin, GAME.world.width - margin),
      y: clamp(y, margin, GAME.world.height - margin),
    };
  }

  /**
   * Daten für die HUD-Anzeige.
   * @param {number} now
   */
  hudState(now) {
    return {
      active: this.combo.active,
      commands: this.commands.map((c) => ({
        id: c.id,
        name: c.shortName,
        sequence: c.sequence,
        progress: this.combo.progressFor(c.id),
        ready: this.cooldowns.isReady(c.id, now),
        remainingMs: this.cooldowns.remaining(c.id, now),
        cooldownProgress: this.cooldowns.progress(c.id, now),
      })),
    };
  }

  /** Aufräumen beim Beenden der Szene. */
  destroy() {
    this.scene.input.keyboard?.off('keydown', this.onKeyDown);
    for (const entry of this.pending) entry.marker.destroy();
    this.pending = [];
  }
}