import { AUDIO_CONFIG } from "../config/gameConfig.js";

export class UIManager {
  constructor() {
    // HUD elements
    this.moneyEl = document.getElementById("money");
    this.livesEl = document.getElementById("lives");
    this.waveEl = document.getElementById("wave");
    this.wavesTotalEl = document.getElementById("wavesTotal");
    this.messagesEl = document.getElementById("messages");
    this.restartBtn = document.getElementById("restart");

    // Upgrade panel elements
    this.upgradePanel = document.getElementById("upgradePanel");
    this.upgradeBtn = document.getElementById("upgradeBtn");
    this.sellBtn = document.getElementById("sellBtn");
    this.tLevelEl = document.getElementById("t_level");
    this.tRangeEl = document.getElementById("t_range");
    this.tRateEl = document.getElementById("t_rate");
    this.tDamageEl = document.getElementById("t_damage");
    this.tNextCostEl = document.getElementById("t_nextCost");

    // Tower palette (floating)
    this.palette = document.createElement("div");
    this.palette.className = "palette hidden";
    document.body.appendChild(this.palette);

    // Audio system
    this.audioCache = {};
    this.backgroundMusic = null;
    this.musicVolume = AUDIO_CONFIG.musicVolume;
    this.effectsVolume = AUDIO_CONFIG.effectsVolume;
    this.initAudio();

    this._paletteClickHandler = null;
    this._outsideHandler = (ev) => {
      if (this.palette.style.display === "none") return;
      if (!this.palette.contains(ev.target)) {
        this.hideTowerPalette();
        if (this._paletteCancelCb) this._paletteCancelCb();
      }
    };
    this._escHandler = (ev) => {
      if (ev.key === "Escape" && this.palette.style.display !== "none") {
        this.hideTowerPalette();
        if (this._paletteCancelCb) this._paletteCancelCb();
      }
    };
    window.addEventListener("mousedown", this._outsideHandler);
    window.addEventListener("keydown", this._escHandler);

    this._paletteSelectCb = null;
    this._paletteCancelCb = null;

    // Speed controls (top-right UI)
    this._speedChangeCb = null;
    this.speedContainer = null;
    this.speedBtn1 = null;
    this.speedBtn2 = null;

    // Game state subscription placeholders
    this._moneyChangedHandler = null;
    this._gameStateForSubscriptions = null;

    // Sync initial HUD visibility with new CSS classes
    if (this.restartBtn) this.restartBtn.classList.add("hidden");
    if (this.upgradePanel) this.upgradePanel.classList.add("hidden");
  }

  // Init and update for speed controls
  initSpeedControls(initialSpeed = 1) {
    if (this.speedContainer) return; // already initialized

    const container = document.createElement("div");
    container.className = "speed-controls";

    const makeBtn = (label, pressed = false) => {
      const b = document.createElement("button");
      b.textContent = label;
      b.className = "btn btn--toggle";
      b.setAttribute("aria-pressed", pressed ? "true" : "false");
      b.type = "button";
      return b;
    };

    const b1 = makeBtn("x1", initialSpeed === 1);
    const b2 = makeBtn("x2", initialSpeed === 2);

    b1.addEventListener("click", (e) => {
      e.stopPropagation();
      this._setActiveSpeed(1);
      if (this._speedChangeCb) this._speedChangeCb(1);
    });
    b2.addEventListener("click", (e) => {
      e.stopPropagation();
      this._setActiveSpeed(2);
      if (this._speedChangeCb) this._speedChangeCb(2);
    });

    container.appendChild(b1);
    container.appendChild(b2);
    document.body.appendChild(container);

    this.speedContainer = container;
    this.speedBtn1 = b1;
    this.speedBtn2 = b2;

    this.updateSpeedControls(initialSpeed);
  }

  onSpeedChange(callback) {
    this._speedChangeCb = callback;
  }

  updateSpeedControls(currentSpeed = 1) {
    if (!this.speedBtn1 || !this.speedBtn2) return;
    this.speedBtn1.setAttribute(
      "aria-pressed",
      currentSpeed === 1 ? "true" : "false"
    );
    this.speedBtn2.setAttribute(
      "aria-pressed",
      currentSpeed === 2 ? "true" : "false"
    );
  }

  _setActiveSpeed(s) {
    this.updateSpeedControls(s);
  }

  /**
   * Subscribe UI to GameState money changes and perform initial affordability update.
   * Call this once during UI initialization when GameState instance is available.
   */
  initWithGameState(gameState) {
    if (!gameState || this._gameStateForSubscriptions) return;
    this._gameStateForSubscriptions = gameState;

    // Bind once to keep reference for unsubscription
    this._moneyChangedHandler = (newMoney /*, prevMoney */) => {
      this.updateTowerAffordability(newMoney);
    };

    // Prefer dedicated helpers if available; fall back to generic on/off
    if (typeof gameState.subscribeMoneyChanged === "function") {
      gameState.subscribeMoneyChanged(this._moneyChangedHandler);
    } else if (typeof gameState.on === "function") {
      gameState.on("moneyChanged", this._moneyChangedHandler);
    }

    // Initial affordability update using current money
    this.updateTowerAffordability(gameState.money);
  }

  /**
   * Update HUD labels and also ensure tower affordability matches current money.
   */
  updateHUD(gameState) {
    this.moneyEl.textContent = String(gameState.money);
    this.livesEl.textContent = String(gameState.lives);

    // Infinite waves: display current wave only
    const currentWave = gameState.waveIndex + 1;
    this.waveEl.textContent = String(currentWave);

    // If total waves element exists, show infinity symbol
    if (this.wavesTotalEl) {
      this.wavesTotalEl.textContent = "∞";
    }

    if (gameState.gameOver || gameState.gameWon) {
      this.restartBtn.classList.remove("hidden");
    } else {
      this.restartBtn.classList.add("hidden");
    }

    // Keep palette/button states in sync with current money on HUD updates too
    this.updateTowerAffordability(gameState.money);
  }

  setMessage(text) {
    this.messagesEl.textContent = text;
  }

  setWavesTotal(total) {
    this.wavesTotalEl.textContent = String(total);
  }

  showUpgradePanel(tower, money) {
    this.upgradePanel.classList.remove("hidden");
    this.tLevelEl.textContent = String(tower.level);
    this.tRangeEl.textContent = tower.range.toFixed(2);
    this.tRateEl.textContent = tower.rate.toFixed(2);
    this.tDamageEl.textContent = tower.damage.toFixed(2);

    if (tower.canUpgrade) {
      this.tNextCostEl.textContent = String(tower.nextUpgradeCost);
      this.upgradeBtn.disabled = money < tower.nextUpgradeCost;
    } else {
      this.tNextCostEl.textContent = "Max";
      this.upgradeBtn.disabled = true;
    }

    this.sellBtn.disabled = false;
  }

  hideUpgradePanel() {
    this.upgradePanel.classList.add("hidden");
  }

  onRestartClick(callback) {
    this.restartBtn.addEventListener("click", callback);
  }

  onUpgradeClick(callback) {
    this.upgradeBtn.addEventListener("click", (e) => {
      e.stopPropagation();
      callback();
    });
  }

  onSellClick(callback) {
    this.sellBtn.addEventListener("click", (e) => {
      e.stopPropagation();
      callback();
    });
  }

  // Palette API
  onPaletteSelect(callback) {
    this._paletteSelectCb = callback;
  }
  onPaletteCancel(callback) {
    this._paletteCancelCb = callback;
  }

  // Utility: build default palette options using game config
  _defaultTowerOptions() {
    // Prefer static ESM import at top of module for browser compatibility.
    // We cache config on the instance if dynamic import is needed elsewhere.
    if (!this._cfgSync) {
      // Fallback in case not yet set by updateTowerAffordability's dynamic import
      // but since gameConfig is an ESM and likely already evaluated via imports,
      // we can safely rely on synchronous import by hoisting at top-level if desired.
    }
    // Use a synchronous named import by referencing cached module if present;
    // otherwise import statically at top of file would be ideal.
    const TOWER_TYPES = (this._cfg && this._cfg.TOWER_TYPES) || undefined;
    // If not cached yet, we can safely reference a top-level import added by bundlers.
    // To avoid runtime errors, guard and build using an empty array if config missing temporarily.
    const types = TOWER_TYPES;
    const opts = [];

    const push = (t, extra = {}) => {
      if (!t) return;
      opts.push({
        key: t.key,
        name: t.name,
        cost: t.cost,
        enabled: true,
        desc:
          t.type === "slow"
            ? "Applies slow on hit"
            : t.type === "sniper"
            ? "Long-range high damage"
            : t.type === "electric"
            ? "Electric arcs hit up to 3 enemies"
            : "Basic all-round tower",
        color:
          t.type === "slow"
            ? "#ff69b4"
            : t.type === "sniper"
            ? "#00ffff"
            : t.type === "electric"
            ? "#9ad6ff"
            : "#3a97ff",
        ...extra,
      });
    };

    if (types) {
      push(types.basic);
      push(types.slow);
      push(types.sniper);
      // Ensure Electric shows in palette
      if (types.electric) push(types.electric);
    }
    return opts;
  }

  /**
   * Update tower selection UI items (currently palette items) based on affordability.
   * Only adjusts enabled/disabled state and optional 'unaffordable' class.
   */
  updateTowerAffordability(currentMoney) {
    // Current implementation creates palette items dynamically in showTowerPalette.
    // When palette is open, update existing rendered items accordingly.
    const list = this.palette.querySelector(".palette-list");
    if (!list) return;

    // Read costs from config via dynamic ESM import for browser compatibility
    // Cache the loaded module on the instance to avoid re-fetching.
    if (!this._cfgPromise) {
      this._cfgPromise = import("../config/gameConfig.js").then((m) => {
        this._cfg = m;
        return m;
      });
    }

    this._cfgPromise.then(({ TOWER_TYPES }) => {
      const costByKey = {
        basic: TOWER_TYPES.basic?.cost,
        slow: TOWER_TYPES.slow?.cost,
        sniper: TOWER_TYPES.sniper?.cost,
        electric: TOWER_TYPES.electric?.cost,
      };

      // Iterate palette items in DOM (each item corresponds to one tower option)
      const items = list.querySelectorAll(".palette-item");
      items.forEach((item) => {
        // Determine tower key for this item by reading its label text
        // Labels are created as the first span with the tower name
        const labelSpan = item.querySelector("span:first-child");
        const name = labelSpan ? labelSpan.textContent : "";
        // Map name back to key via config
        let key = null;
        for (const k of Object.keys(TOWER_TYPES)) {
          if (TOWER_TYPES[k]?.name === name) {
            key = k;
            break;
          }
        }
        if (!key) return;

        const cost = costByKey[key];
        const affordable =
          typeof cost === "number" ? cost <= currentMoney : false;

        // Disable/enable via aria-disabled like current structure uses
        if (affordable) {
          item.removeAttribute("aria-disabled");
          item.classList.remove("unaffordable");
        } else {
          item.setAttribute("aria-disabled", "true");
          // Optional class; safe to add/remove if styles define it
          item.classList.add("unaffordable");
        }
      });
    });
  }

  showTowerPalette(screenX, screenY, options) {
    // options: [{key, name, cost, enabled, desc, color}]
    this.palette.innerHTML = "";

    const title = document.createElement("div");
    title.textContent = "Choose a tower";
    title.className = "palette-title";
    this.palette.appendChild(title);

    // If no options provided, build from config (includes Electric)
    const opts =
      Array.isArray(options) && options.length > 0
        ? options
        : this._defaultTowerOptions();

    const list = document.createElement("div");
    list.className = "palette-list";

    opts.forEach((opt) => {
      const item = document.createElement("div");
      item.className = "palette-item";
      if (!opt.enabled) {
        item.setAttribute("aria-disabled", "true");
      }
      const label = document.createElement("span");
      label.textContent = opt.name;

      const cost = document.createElement("span");
      cost.textContent = `${opt.cost}${opt.key === "electric" ? " ⚡" : ""}`;
      cost.style.fontFamily = "var(--font-mono)";

      if (opt.color) {
        item.style.boxShadow = `inset 0 0 0 2px ${opt.color}33`;
      }
      item.title = opt.desc || "";
      item.addEventListener("click", (e) => {
        e.stopPropagation();
        // Rely on live affordability state; opt.enabled may be stale after updates
        if (!item.hasAttribute("aria-disabled")) {
          this.hideTowerPalette();
          if (this._paletteSelectCb) this._paletteSelectCb(opt.key);
        }
      });

      item.appendChild(label);
      item.appendChild(cost);
      list.appendChild(item);
    });

    this.palette.appendChild(list);

    // Position palette initially to measure its size
    this.palette.style.width = "200px";
    this.palette.classList.remove("hidden");
    
    // Get actual dimensions after rendering
    const rect = this.palette.getBoundingClientRect();
    const menuWidth = rect.width;
    const menuHeight = rect.height;
    
    // Calculate position with proper bounds checking
    const pad = 8;
    let left = screenX + 10;
    let top = screenY + 10;
    
    // Ensure menu stays within viewport horizontally
    if (left + menuWidth + pad > window.innerWidth) {
      left = window.innerWidth - menuWidth - pad;
    }
    if (left < pad) {
      left = pad;
    }
    
    // Ensure menu stays within viewport vertically
    if (top + menuHeight + pad > window.innerHeight) {
      // Try placing above the click point instead
      top = screenY - menuHeight - 10;
      if (top < pad) {
        // If still doesn't fit, just cap at bottom of screen
        top = window.innerHeight - menuHeight - pad;
      }
    }
    if (top < pad) {
      top = pad;
    }
    
    // Apply calculated position
    this.palette.style.left = left + "px";
    this.palette.style.top = top + "px";

    // After rendering, ensure initial affordability reflects current money if subscribed
    if (this._gameStateForSubscriptions) {
      this.updateTowerAffordability(this._gameStateForSubscriptions.money);
    }
  }

  hideTowerPalette() {
    this.palette.classList.add("hidden");
  }

  // Audio initialization
  initAudio() {
    // Load sound effects
    const soundFiles = {
      basic: "./src/assets/basic.mp3",
      slow: "./src/assets/slow.mp3",
      sniper: "./src/assets/sniper.mp3",
      electric: "./src/assets/electric.mp3"
    };

    for (const [type, path] of Object.entries(soundFiles)) {
      try {
        const audio = new Audio(path);
        audio.volume = this.effectsVolume;
        audio.preload = "auto";
        this.audioCache[type] = audio;
      } catch (e) {
        console.warn(`Failed to load sound for ${type}:`, e);
      }
    }

    // Load and start background music
    if (AUDIO_CONFIG.musicEnabled) {
      try {
        console.log("Loading background music...");
        this.backgroundMusic = new Audio("./src/assets/music.mp3");
        this.backgroundMusic.volume = this.musicVolume;
        this.backgroundMusic.loop = true;
        this.backgroundMusic.preload = "auto";
        
        // Add multiple event listeners for debugging
        this.backgroundMusic.addEventListener('loadstart', () => {
          console.log("Music load started");
        });
        
        this.backgroundMusic.addEventListener('canplay', () => {
          console.log("Music can play");
        });
        
        this.backgroundMusic.addEventListener('error', (e) => {
          console.error("Music load error:", e);
        });
        
        // Start playing music when it's loaded
        this.backgroundMusic.addEventListener('canplaythrough', () => {
          console.log("Music loaded, attempting to play...");
          this.backgroundMusic.play().then(() => {
            console.log("Music playing successfully!");
          }).catch(e => {
            console.log("Music autoplay blocked, will play on user interaction", e);
            // Fallback: play on first user interaction
            const playOnInteraction = () => {
              console.log("Attempting to play music on user interaction...");
              this.backgroundMusic.play().then(() => {
                console.log("Music started after user interaction!");
              }).catch((err) => {
                console.error("Failed to play music:", err);
              });
              document.removeEventListener('click', playOnInteraction);
              document.removeEventListener('keydown', playOnInteraction);
            };
            document.addEventListener('click', playOnInteraction);
            document.addEventListener('keydown', playOnInteraction);
          });
        }, { once: true });
        
        // Force load
        this.backgroundMusic.load();
      } catch (e) {
        console.warn("Failed to load background music:", e);
      }
    } else {
      console.log("Music is disabled in config");
    }
  }

  // Play shooting sound for a tower
  playTowerSound(tower) {
    if (!tower || !tower.type || !AUDIO_CONFIG.effectsEnabled) return;
    
    const audio = this.audioCache[tower.type];
    if (audio) {
      try {
        // Clone and play to allow overlapping sounds
        const audioClone = audio.cloneNode();
        audioClone.volume = this.effectsVolume;
        audioClone.play().catch(() => {});
      } catch (e) {
        // Fallback to direct play if cloning fails
        audio.currentTime = 0;
        audio.volume = this.effectsVolume;
        audio.play().catch(() => {});
      }
    }
  }

  // Sniper aiming tone (optional, can be extended)
  playAimingTone(tower) {
    // Could play a subtle aiming sound if desired
  }

  // Stop aiming tone
  stopAimingTone(tower) {
    // Stop any aiming sound if implemented
  }

  // Sniper fire crack sound
  playFireCrack(tower) {
    // Use the sniper sound for fire crack
    if (tower && tower.type === "sniper") {
      this.playTowerSound(tower);
    }
  }

  // Volume control methods
  setMusicVolume(volume) {
    this.musicVolume = Math.max(0, Math.min(1, volume));
    if (this.backgroundMusic) {
      this.backgroundMusic.volume = this.musicVolume;
    }
  }

  setEffectsVolume(volume) {
    this.effectsVolume = Math.max(0, Math.min(1, volume));
    // Update all cached sound effects
    for (const audio of Object.values(this.audioCache)) {
      if (audio) audio.volume = this.effectsVolume;
    }
  }

  toggleMusic() {
    if (this.backgroundMusic) {
      if (this.backgroundMusic.paused) {
        this.backgroundMusic.play().catch(() => {});
      } else {
        this.backgroundMusic.pause();
      }
    }
  }

  toggleEffects() {
    AUDIO_CONFIG.effectsEnabled = !AUDIO_CONFIG.effectsEnabled;
  }

  /**
   * Optional teardown to prevent leaks: unsubscribe from GameState events.
   */
  destroy() {
    const gs = this._gameStateForSubscriptions;
    if (gs && this._moneyChangedHandler) {
      if (typeof gs.unsubscribeMoneyChanged === "function") {
        gs.unsubscribeMoneyChanged(this._moneyChangedHandler);
      } else if (typeof gs.off === "function") {
        gs.off("moneyChanged", this._moneyChangedHandler);
      }
    }
    this._gameStateForSubscriptions = null;
    this._moneyChangedHandler = null;

    // Existing global listeners cleanup as a best practice
    window.removeEventListener("mousedown", this._outsideHandler);
    window.removeEventListener("keydown", this._escHandler);
  }
}