/**
 * Hexo Game UI - Canvas Rendering and Interactions
 * Supports 2-4 players with AI bots
 */

import { HexMap, CELL_TYPES } from './map.js';
import { AIBot } from './ai-bot.js';

// Game constants
const HEX_SIZE = 14;
const DEFAULT_MAP_SIZE = 20;
const ANIMATION_DURATION = 300;

// Player colors
const PLAYER_COLORS = {
  1: '#4ecca3',  // teal/green
  2: '#e94560',  // red/pink
  3: '#f9ed69',  // yellow
  4: '#00adb5'   // cyan/blue
};

// Colors
const COLORS = {
  blocked: '#2a2a4a',
  empty: '#3a5a6a',
  player1: '#4ecca3',
  player2: '#e94560',
  player3: '#f9ed69',
  player4: '#00adb5',
  highlight: 'rgba(255, 255, 255, 0.3)',
  selected: 'rgba(233, 69, 96, 0.6)',
  target: 'rgba(78, 204, 163, 0.5)',
  stroke: '#1a1a2e',
  text: '#eeeeee',
  textDark: '#1a1a2e',
  dice: '#ffffff',
  diceBorder: '#333333'
};

/**
 * Game UI Controller
 */
class GameUI {
  constructor() {
    this.canvas = document.getElementById('game-canvas');
    this.ctx = this.canvas.getContext('2d');
    this.map = null;
    this.mapSize = DEFAULT_MAP_SIZE;
    this.selectedCell = null;
    this.currentTarget = null;
    this.currentPlayer = 1;
    this.playerCount = 2;
    this.playerTypes = {}; // 1: 'human', 2: 'ai', etc.
    this.aiBots = {};
    this.gamePhase = 'movement';
    this.hasMoved = false;
    this.isAIThinking = false;
    this.isProcessingTurn = false; // Prevent re-entrancy during turn processing

    this.offsetX = 0;
    this.offsetY = 0;

    this.init();
  }

  init() {
    this.setupStartScreen();
    this.setupEventListeners();
  }

  setupStartScreen() {
    const playerCountSelect = document.getElementById('player-count');
    const playerTypeRows = document.querySelectorAll('.player-type-row');
    
    playerCountSelect.addEventListener('change', (e) => {
      const count = parseInt(e.target.value);
      playerTypeRows.forEach((row, index) => {
        row.style.display = index < count ? 'flex' : 'none';
      });
    });
    
    document.getElementById('start-game-btn').addEventListener('click', () => {
      this.startGame();
    });
    
    document.getElementById('back-menu-btn').addEventListener('click', () => {
      this.showStartScreen();
    });
  }

  showStartScreen() {
    document.getElementById('start-screen').style.display = 'flex';
    document.getElementById('game-screen').style.display = 'none';
  }

  startGame() {
    // Get settings
    this.playerCount = parseInt(document.getElementById('player-count').value);
    this.mapSize = parseInt(document.getElementById('map-size').value);

    for (let i = 1; i <= this.playerCount; i++) {
      const typeSelect = document.getElementById(`player${i}-type`);
      this.playerTypes[i] = typeSelect.value;
    }

    // Show game screen
    document.getElementById('start-screen').style.display = 'none';
    document.getElementById('game-screen').style.display = 'flex';

    this.newGame();
  }

  newGame() {
    this.map = new HexMap(this.mapSize);
    this.selectedCell = null;
    this.currentTarget = null;
    this.currentPlayer = 1;
    this.gamePhase = 'movement';
    this.hasMoved = false;
    this.isAIThinking = false;
    this.isProcessingTurn = false;

    // Initialize AI bots AFTER map is created
    this.aiBots = {};
    for (let i = 1; i <= this.playerCount; i++) {
      if (this.playerTypes[i] === 'ai') {
        this.aiBots[i] = new AIBot(i, this.map, this);
      }
    }

    // Initialize starting positions for all players
    this.initializePlayers();

    this.centerMap();
    this.render();
    this.createPlayerCards();
    this.updateUI();
    this.log(`New game started with ${this.playerCount} players!`);
    console.log(`[GAME] New game started with ${this.playerCount} players`);

    // Start first player's turn (AI if needed)
    this.checkAndRunAITurn();
  }

  createPlayerCards() {
    const container = document.getElementById('players-container');
    container.innerHTML = '';
    
    for (let i = 1; i <= this.playerCount; i++) {
      const card = document.createElement('div');
      card.className = `player-card player-${i}${i === 1 ? ' active' : ''}${this.playerTypes[i] === 'ai' ? ' ai-controlled' : ''}`;
      card.id = `player${i}-card`;
      
      card.innerHTML = `
        <h3>Player ${i}${this.playerTypes[i] === 'ai' ? ' (AI)' : ''}</h3>
        <div class="player-stats">
          <div class="stat">
            <span class="stat-label">Cells:</span>
            <span class="stat-value" id="player${i}-cells">0</span>
          </div>
          <div class="stat">
            <span class="stat-label">Supply:</span>
            <span class="stat-value" id="player${i}-supply">0</span>
          </div>
          <div class="stat">
            <span class="stat-label">Strength:</span>
            <span class="stat-value" id="player${i}-strength">0</span>
          </div>
        </div>
      `;
      
      container.appendChild(card);
    }
  }

  initializePlayers() {
    // Place starting units for each player at fixed positions that are always passable
    // Use corners of the map to ensure they don't overlap
    // Positions scale with map size
    const offset = Math.max(1, Math.floor(this.mapSize / 10));
    const positions = [
      { q: offset, r: offset },                           // Player 1 - top-left
      { q: this.mapSize - 1 - offset, r: this.mapSize - 1 - offset },  // Player 2 - bottom-right
      { q: offset, r: this.mapSize - 1 - offset },        // Player 3 - bottom-left
      { q: this.mapSize - 1 - offset, r: offset }         // Player 4 - top-right
    ];

    for (let i = 1; i <= this.playerCount; i++) {
      const pos = positions[i - 1];
      if (!pos) continue;

      // Force the cell to be passable and set ownership
      const cell = this.map.getCell(pos.q, pos.r);
      if (cell) {
        // Make sure cell is passable
        if (cell.type === CELL_TYPES.BLOCKED) {
          cell.type = CELL_TYPES.EMPTY;
        }
        this.map.setOwner(pos.q, pos.r, i);
        cell.setStrength(8);
        console.log(`[GAME] Player ${i} placed at (${pos.q}, ${pos.r})`);
      } else {
        console.error(`[GAME] Failed to place Player ${i} at (${pos.q}, ${pos.r})`);
      }
    }
  }

  centerMap() {
    const canvasWidth = this.canvas.width;
    const canvasHeight = this.canvas.height;

    const sqrt3 = Math.sqrt(3);

    // Calculate actual map bounds based on dynamic map size
    // For pointy-top hex grid:
    // - Width spans from q=0 to q=mapSize-1, with r offset
    // - Rightmost point: (q=mapSize-1, r=mapSize-1) at x = HEX_SIZE * sqrt3 * (mapSize - 1 + (mapSize - 1) / 2)
    // - Height spans from r=0 to r=mapSize-1
    // - Bottommost point: (any q, r=mapSize-1) at y = HEX_SIZE * 1.5 * (mapSize - 1)

    const mapWidth = HEX_SIZE * sqrt3 * ((this.mapSize - 1) + (this.mapSize - 1) / 2);
    const mapHeight = HEX_SIZE * 1.5 * (this.mapSize - 1);

    // Add padding for hex radius (hex extends beyond center point)
    const hexRadius = HEX_SIZE;
    const totalWidth = mapWidth + 2 * hexRadius;
    const totalHeight = mapHeight + 2 * hexRadius;

    // Center the map on canvas
    this.offsetX = (canvasWidth - totalWidth) / 2 + hexRadius;
    this.offsetY = (canvasHeight - totalHeight) / 2 + hexRadius;

    console.log(`[GAME] Map: canvas=${canvasWidth}x${canvasHeight}, map=${mapWidth.toFixed(0)}x${mapHeight.toFixed(0)}, total=${totalWidth.toFixed(0)}x${totalHeight.toFixed(0)}`);
    console.log(`[GAME] Offset: x=${this.offsetX.toFixed(1)}, y=${this.offsetY.toFixed(1)}`);
  }

  setupEventListeners() {
    this.canvas.addEventListener('click', (e) => this.handleClick(e));
    this.canvas.addEventListener('mousemove', (e) => this.handleMouseMove(e));

    document.getElementById('end-turn-btn').addEventListener('click', () => this.endTurn());
    document.getElementById('cancel-btn').addEventListener('click', () => this.cancelSelection());
  }

  hexToPixel(q, r) {
    const sqrt3 = Math.sqrt(3);
    const x = this.offsetX + HEX_SIZE * sqrt3 * (q + r/2);
    const y = this.offsetY + HEX_SIZE * 1.5 * r;
    return { x, y };
  }

  pixelToHex(x, y) {
    const adjX = x - this.offsetX;
    const adjY = y - this.offsetY;

    const sqrt3 = Math.sqrt(3);
    const q = (adjX / (HEX_SIZE * sqrt3) - adjY / (HEX_SIZE * 1.5) / 2);
    const r = adjY / (HEX_SIZE * 1.5);

    const qi = Math.round(q);
    const ri = Math.round(r);

    if (qi >= 0 && qi < this.mapSize && ri >= 0 && ri < this.mapSize) {
      return { q: qi, r: ri };
    }
    return null;
  }

  getValidTargets(q, r) {
    const directions = [
      [+1, -1],  // north-east
      [0, -1],   // north-west
      [-1, 0],   // west
      [-1, +1],  // south-west
      [0, +1],   // south-east
      [+1, 0]    // east
    ];

    const targets = [];
    for (const [dq, dr] of directions) {
      const nq = q + dq;
      const nr = r + dr;
      if (nq >= 0 && nq < this.mapSize && nr >= 0 && nr < this.mapSize) {
        const cell = this.map.getCell(nq, nr);
        if (cell && cell.isPassable()) {
          targets.push(cell);
        }
      }
    }
    return targets;
  }

  drawHex(q, r, fillStyle, strokeStyle = COLORS.stroke, lineWidth = 2) {
    const { x, y } = this.hexToPixel(q, r);
    const size = HEX_SIZE * 0.98;

    const vertices = [];
    for (let i = 0; i < 6; i++) {
      const angle = Math.PI / 6 + (Math.PI / 3) * i;
      vertices.push({
        x: x + size * Math.cos(angle),
        y: y + size * Math.sin(angle)
      });
    }

    this.ctx.beginPath();
    this.ctx.moveTo(vertices[0].x, vertices[0].y);
    for (let i = 1; i < vertices.length; i++) {
      this.ctx.lineTo(vertices[i].x, vertices[i].y);
    }
    this.ctx.closePath();

    this.ctx.fillStyle = fillStyle;
    this.ctx.fill();

    this.ctx.strokeStyle = strokeStyle;
    this.ctx.lineWidth = lineWidth;
    this.ctx.stroke();
  }

  drawDice(cell) {
    if (cell.dice.length === 0) return;
    
    const { x, y } = this.hexToPixel(cell.q, cell.r);
    const strength = cell.getStrength();
    
    this.ctx.fillStyle = COLORS.text;
    this.ctx.font = 'bold 11px Arial';
    this.ctx.textAlign = 'center';
    this.ctx.textBaseline = 'middle';
    this.ctx.fillText(strength.toString(), x, y - 3);
    
    if (cell.dice.length > 1) {
      const dotY = y + 8;
      for (let i = 0; i < Math.min(cell.dice.length, 5); i++) {
        this.ctx.beginPath();
        this.ctx.arc(x - 6 + i * 4, dotY, 1.5, 0, Math.PI * 2);
        this.ctx.fillStyle = COLORS.dice;
        this.ctx.fill();
      }
    }
  }

  drawOwnerIndicator(cell) {
    if (!cell.isOwned()) return;

    const { x, y } = this.hexToPixel(cell.q, cell.r);
    const ownerColor = PLAYER_COLORS[cell.getOwner()] || COLORS.player1;
    const size = HEX_SIZE * 0.98 - 3;

    const vertices = [];
    for (let i = 0; i < 6; i++) {
      const angle = Math.PI / 6 + (Math.PI / 3) * i;
      vertices.push({
        x: x + size * Math.cos(angle),
        y: y + size * Math.sin(angle)
      });
    }

    this.ctx.beginPath();
    this.ctx.moveTo(vertices[0].x, vertices[0].y);
    for (let i = 1; i < vertices.length; i++) {
      this.ctx.lineTo(vertices[i].x, vertices[i].y);
    }
    this.ctx.closePath();
    this.ctx.strokeStyle = ownerColor;
    this.ctx.lineWidth = 3;
    this.ctx.stroke();
  }

  render() {
    this.ctx.fillStyle = COLORS.stroke;
    this.ctx.fillRect(0, 0, this.canvas.width, this.canvas.height);

    if (!this.map) return;

    for (let r = 0; r < this.mapSize; r++) {
      for (let q = 0; q < this.mapSize; q++) {
        const cell = this.map.getCell(q, r);
        let color;

        if (cell.type === CELL_TYPES.BLOCKED) {
          color = COLORS.blocked;
        } else if (cell.type === CELL_TYPES.PLAYER1) {
          color = COLORS.player1;
        } else if (cell.type === CELL_TYPES.PLAYER2) {
          color = COLORS.player2;
        } else if (cell.type === CELL_TYPES.PLAYER3) {
          color = COLORS.player3;
        } else if (cell.type === CELL_TYPES.PLAYER4) {
          color = COLORS.player4;
        } else {
          color = COLORS.empty;
        }

        if (!cell.isOwned()) {
          color = this.hexToRgba(color, 0.6);
        }

        this.drawHex(q, r, color);
        this.drawOwnerIndicator(cell);
        this.drawDice(cell);
      }
    }

    if (this.selectedCell) {
      this.drawHex(
        this.selectedCell.q,
        this.selectedCell.r,
        COLORS.selected,
        COLORS.text,
        3
      );

      const targets = this.getValidTargets(this.selectedCell.q, this.selectedCell.r);
      for (const target of targets) {
        if (target.getOwner() !== this.currentPlayer) {
          this.drawHex(
            target.q,
            target.r,
            COLORS.target,
            PLAYER_COLORS[this.currentPlayer] || COLORS.player1,
            2
          );
        }
      }
    }
  }

  hexToRgba(hex, alpha) {
    const r = parseInt(hex.slice(1, 3), 16);
    const g = parseInt(hex.slice(3, 5), 16);
    const b = parseInt(hex.slice(5, 7), 16);
    return `rgba(${r}, ${g}, ${b}, ${alpha})`;
  }

  handleClick(e) {
    if (this.gamePhase !== 'movement') return;
    if (this.playerTypes[this.currentPlayer] === 'ai') return;
    
    const rect = this.canvas.getBoundingClientRect();
    const x = e.clientX - rect.left;
    const y = e.clientY - rect.top;
    
    const hexPos = this.pixelToHex(x, y);
    if (!hexPos) return;
    
    const cell = this.map.getCell(hexPos.q, hexPos.r);
    if (!cell || !cell.isPassable()) return;
    
    if (this.selectedCell === null) {
      if (cell.getOwner() === this.currentPlayer && cell.getStrength() > 1) {
        this.selectedCell = cell;
        this.updateUI();
        this.render();
      }
    } else {
      if (cell === this.selectedCell) {
        this.cancelSelection();
        return;
      }

      const targets = this.getValidTargets(this.selectedCell.q, this.selectedCell.r);
      const isValidTarget = targets.some(n => n.q === cell.q && n.r === cell.r);

      if (cell.getOwner() === this.currentPlayer) {
        if (cell.getStrength() > 1) {
          this.selectedCell = cell;
          this.updateUI();
          this.render();
        }
        return;
      }

      if (isValidTarget) {
        this.currentTarget = cell;
        this.executeAttack();
      } else {
        this.cancelSelection();
      }
    }
  }

  handleMouseMove(e) {
    // Hover effects could be added here
  }

  executeAttack() {
    if (!this.selectedCell || !this.currentTarget) return;

    const attacker = this.selectedCell;
    const defender = this.currentTarget;
    const attackStrength = attacker.getStrength() - 1;

    if (defender.type === CELL_TYPES.EMPTY || defender.getOwner() !== this.currentPlayer) {
      let defenseStrength = defender.getStrength();

      if (defenseStrength > 0) {
        const attackRoll = Math.floor(Math.random() * attackStrength) + 1;
        const defenseRoll = Math.floor(Math.random() * defenseStrength) + 1;

        this.log(`P${this.currentPlayer} Attack: ${attackStrength} vs ${defenseStrength} | Roll: ${attackRoll} vs ${defenseRoll}`);

        if (attackRoll > defenseRoll) {
          const remainingStrength = attackRoll - 1;
          attacker.setStrength(1);

          if (remainingStrength > 0) {
            defender.setStrength(remainingStrength);
            this.map.setOwner(defender.q, defender.r, this.currentPlayer);
            this.log(`Victory! Captured with strength ${remainingStrength}`, 'victory');
          }
        } else {
          const remainingDefense = defenseRoll - attackRoll;
          defender.setStrength(Math.max(1, remainingDefense));
          attacker.setStrength(1);
          this.log(`Attack repelled! Defender has ${Math.max(1, remainingDefense)}`, 'defeat');
        }
      } else {
        attacker.setStrength(1);
        defender.setStrength(attackStrength);
        this.map.setOwner(defender.q, defender.r, this.currentPlayer);
        this.log(`Captured empty cell with strength ${attackStrength}`);
      }
    }

    this.hasMoved = true;
    this.cancelSelection();
    this.render();
    this.updateUI();
  }

  cancelSelection() {
    this.selectedCell = null;
    this.currentTarget = null;
    this.updateUI();
    this.render();
  }

  async endTurn() {
    if (this.gamePhase !== 'movement') {
      console.log(`[GAME] endTurn() called but gamePhase is '${this.gamePhase}', ignoring`);
      return;
    }

    // Prevent re-entrancy - only one turn processing at a time
    if (this.isProcessingTurn) {
      console.log(`[GAME] endTurn() called but isProcessingTurn is true, ignoring`);
      return;
    }

    this.isProcessingTurn = true;
    console.log(`[GAME] endTurn() - Player ${this.currentPlayer} ending turn`);

    try {
      // Apply supply
      const supply = this.map.calculateSupply(this.currentPlayer);
      this.distributeSupply(supply);
      this.log(`Player ${this.currentPlayer} received ${supply} supply`);
      console.log(`[GAME] Player ${this.currentPlayer} received ${supply} supply`);

      // Next player
      const previousPlayer = this.currentPlayer;
      this.currentPlayer = (this.currentPlayer % this.playerCount) + 1;
      this.hasMoved = false;

      console.log(`[GAME] Turn transition: P${previousPlayer} -> P${this.currentPlayer}`);

      this.cancelSelection();
      this.updateUI();
      this.render();

      this.log(`Player ${this.currentPlayer}'s turn`);
      console.log(`[GAME] Player ${this.currentPlayer}'s turn started (${this.playerTypes[this.currentPlayer]})`);

      // Reset isProcessingTurn BEFORE awaiting AI turn
      // This allows the next AI's endTurn() call to proceed
      this.isProcessingTurn = false;
      
      // Check if next player is AI and await completion
      await this.checkAndRunAITurn();
    } catch (error) {
      console.error(`[GAME] Error in endTurn():`, error);
      this.log(`Error during turn transition: ${error.message}`, 'error');
      this.isProcessingTurn = false;
    }
  }

  /**
   * Check if current player is AI and run their turn
   * @returns {Promise<boolean>} - true if AI turn was run, false if human turn
   */
  async checkAndRunAITurn() {
    if (this.playerTypes[this.currentPlayer] === 'ai' && this.aiBots[this.currentPlayer]) {
      console.log(`[AI] Player ${this.currentPlayer} is AI, starting turn`);
      this.isAIThinking = true;
      this.updateUI();

      try {
        // Run AI turn and wait for it to complete
        await this.aiBots[this.currentPlayer].playTurn();
        console.log(`[AI] Player ${this.currentPlayer} AI turn completed`);
        return true;
      } catch (error) {
        console.error(`[AI] Error during Player ${this.currentPlayer} AI turn:`, error);
        this.log(`AI error: ${error.message}`, 'error');
        this.isAIThinking = false;
        this.updateUI();
        // Still advance to next player even on error
        return true;
      } finally {
        // Always reset the flag when AI turn completes (success or error)
        this.isAIThinking = false;
        console.log(`[AI] Player ${this.currentPlayer} isAIThinking reset to false`);
      }
    }
    console.log(`[AI] Player ${this.currentPlayer} is human, no AI turn needed`);
    return false;
  }

  distributeSupply(supply) {
    const playerCells = this.map.getPlayerCells(this.currentPlayer);
    const eligibleCells = playerCells.filter(cell => !cell.isMaxStrength());

    if (eligibleCells.length === 0 || supply === 0) return;

    let remainingSupply = supply;
    while (remainingSupply > 0 && eligibleCells.length > 0) {
      const randomCell = eligibleCells[Math.floor(Math.random() * eligibleCells.length)];
      const currentStrength = randomCell.getStrength();

      if (currentStrength < 48) {
        randomCell.setStrength(currentStrength + 1);
        remainingSupply--;
      }

      if (randomCell.isMaxStrength()) {
        eligibleCells.splice(eligibleCells.indexOf(randomCell), 1);
      }
    }
  }

  updateUI() {
    // Update all player cards
    for (let i = 1; i <= this.playerCount; i++) {
      const playerCells = this.map.getPlayerCells(i);
      const playerStrength = playerCells.reduce((sum, c) => sum + c.getStrength(), 0);
      const playerSupply = this.map.calculateSupply(i);

      document.getElementById(`player${i}-cells`).textContent = playerCells.length;
      document.getElementById(`player${i}-supply`).textContent = playerSupply;
      document.getElementById(`player${i}-strength`).textContent = playerStrength;

      const card = document.getElementById(`player${i}-card`);
      card.classList.toggle('active', i === this.currentPlayer);
    }

    document.getElementById('current-turn').textContent = this.currentPlayer;
    document.getElementById('game-phase').textContent = this.gamePhase;

    // Update map size display
    document.getElementById('map-size-display').textContent = `${this.mapSize}x${this.mapSize}`;

    const instruction = document.getElementById('action-instruction');
    if (this.selectedCell) {
      instruction.textContent = `Select target (strength: ${this.selectedCell.getStrength()})`;
    } else if (this.playerTypes[this.currentPlayer] === 'ai') {
      instruction.textContent = 'AI is thinking...';
    } else {
      instruction.textContent = 'Select a cell with dice to move';
    }

    const cellInfo = document.getElementById('selected-cell-info');
    cellInfo.style.display = 'block';

    if (this.selectedCell) {
      document.getElementById('cell-strength').textContent = this.selectedCell.getStrength();
      document.getElementById('cell-dice').textContent = this.selectedCell.dice.length;
    } else {
      document.getElementById('cell-strength').textContent = '-';
      document.getElementById('cell-dice').textContent = '-';
    }

    const cancelBtn = document.getElementById('cancel-btn');
    const endTurnBtn = document.getElementById('end-turn-btn');

    cancelBtn.disabled = !this.selectedCell || this.playerTypes[this.currentPlayer] === 'ai';
    endTurnBtn.disabled = this.playerTypes[this.currentPlayer] === 'ai';
  }

  log(message, type = '') {
    const logContainer = document.getElementById('battle-log');
    const entry = document.createElement('div');
    entry.className = `log-entry ${type}`;
    entry.textContent = `[P${this.currentPlayer}] ${message}`;
    logContainer.insertBefore(entry, logContainer.firstChild);
    
    while (logContainer.children.length > 50) {
      logContainer.removeChild(logContainer.lastChild);
    }
  }
}

// Initialize game when DOM is ready
document.addEventListener('DOMContentLoaded', () => {
  window.game = new GameUI();
});