/**
 * Hexo Game UI - Canvas Rendering and Interactions
 */

import { HexMap, CELL_TYPES } from './map.js';

// Game constants
const HEX_SIZE = 18;
const MAP_SIZE = 20;
const ANIMATION_DURATION = 300;

// Colors
const COLORS = {
  blocked: '#2a2a4a',
  empty: '#3a5a6a',
  player1: '#4ecca3',
  player2: '#e94560',
  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.selectedCell = null;
    this.currentTarget = null;
    this.currentPlayer = 1;
    this.gamePhase = 'movement'; // movement, supply, gameover
    this.hasMoved = false;
    
    this.offsetX = 0;
    this.offsetY = 0;
    
    this.init();
  }

  init() {
    this.setupEventListeners();
    this.newGame();
    console.log('Game initialized');
  }

  newGame() {
    this.map = new HexMap(MAP_SIZE);
    console.log('Map created, cells:', this.map.cells.size);
    this.selectedCell = null;
    this.currentTarget = null;
    this.currentPlayer = 1;
    this.gamePhase = 'movement';
    this.hasMoved = false;
    
    // Initialize starting positions
    this.initializePlayers();
    
    this.centerMap();
    this.render();
    this.updateUI();
    this.log('New game started! Player 1\'s turn.');
  }

  initializePlayers() {
    // Get random empty cells for each player
    const emptyCells = this.map.getEmptyCells();
    
    // Shuffle and pick starting positions
    const shuffled = emptyCells.sort(() => Math.random() - 0.5);
    
    // Player 1 starting position (top-left area)
    const p1Cell = shuffled.find(c => c.q < 8 && c.r < 8);
    if (p1Cell) {
      this.map.setOwner(p1Cell.q, p1Cell.r, 1);
      p1Cell.setStrength(8); // Starting strength
    }
    
    // Player 2 starting position (bottom-right area)
    const p2Cell = shuffled.find(c => c.q > 10 && c.r > 10 && c.type === CELL_TYPES.EMPTY);
    if (p2Cell) {
      this.map.setOwner(p2Cell.q, p2Cell.r, 2);
      p2Cell.setStrength(8);
    }
  }

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

    const sqrt3 = Math.sqrt(3);
    // Map dimensions for pointy-top hex grid
    const mapWidth = HEX_SIZE * sqrt3 * (MAP_SIZE + MAP_SIZE/2);
    const mapHeight = HEX_SIZE * 1.5 * (MAP_SIZE - 1) + HEX_SIZE * 2;

    this.offsetX = (canvasWidth - mapWidth) / 2 + HEX_SIZE * sqrt3;
    this.offsetY = (canvasHeight - mapHeight) / 2 + HEX_SIZE;
  }

  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('new-game-btn').addEventListener('click', () => this.newGame());
    document.getElementById('cancel-btn').addEventListener('click', () => this.cancelSelection());
  }

  hexToPixel(q, r) {
    // Pointy-top hex grid with proper adjacency
    // For pointy-top: width = sqrt(3) * size, height = 2 * size
    // Horizontal spacing = width = sqrt(3) * size
    // Vertical spacing = 3/4 * height = 1.5 * size
    const sqrt3 = Math.sqrt(3);
    
    // Convert axial to pixel coordinates for pointy-top hex
    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 < MAP_SIZE && ri >= 0 && ri < MAP_SIZE) {
      return { q: qi, r: ri };
    }
    return null;
  }

  /**
   * Get neighboring cells for pointy-top hex grid
   * Directions for pointy-top hex in axial coordinates:
   * - north-east: (+1, -1)
   * - north-west: (0, -1)
   * - west: (-1, 0)
   * - south-west: (-1, +1)
   * - south-east: (0, +1)
   * - east: (+1, 0)
   */
  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 < MAP_SIZE && nr >= 0 && nr < MAP_SIZE) {
        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);

    // Draw pointy-top hexagon - size matches grid spacing
    const size = HEX_SIZE * 0.98; // Almost full size for tight fit

    // Pointy-top hexagon vertices (flat sides left/right)
    const vertices = [];
    for (let i = 0; i < 6; i++) {
      const angle = Math.PI / 6 + (Math.PI / 3) * i; // Start at 30 degrees
      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();
    
    // Draw strength number
    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);
    
    // Draw dice count indicator (small dots)
    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 = cell.getOwner() === 1 ? COLORS.player1 : COLORS.player2;

    // Draw border matching the hexagon shape
    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() {
    // Clear canvas
    this.ctx.fillStyle = COLORS.stroke;
    this.ctx.fillRect(0, 0, this.canvas.width, this.canvas.height);
    
    if (!this.map) return;
    
    // Draw all cells
    for (let r = 0; r < MAP_SIZE; r++) {
      for (let q = 0; q < MAP_SIZE; 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 {
          color = COLORS.empty;
        }
        
        // Apply transparency for non-owned cells
        if (!cell.isOwned()) {
          color = this.hexToRgba(color, 0.6);
        }
        
        this.drawHex(q, r, color);
        this.drawOwnerIndicator(cell);
        this.drawDice(cell);
      }
    }
    
    // Draw selection highlight
    if (this.selectedCell) {
      this.drawHex(
        this.selectedCell.q,
        this.selectedCell.r,
        COLORS.selected,
        COLORS.text,
        3
      );

      // Highlight valid targets (not blocked, not own)
      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,
            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;
    
    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;
    
    // Handle cell selection
    if (this.selectedCell === null) {
      // Select own cell with strength > 1
      if (cell.getOwner() === this.currentPlayer && cell.getStrength() > 1) {
        this.selectedCell = cell;
        this.instruction = `Select target cell or cancel`;
        this.updateUI();
        this.render();
      }
    } else {
      // Check if clicking on same cell - deselect
      if (cell === this.selectedCell) {
        this.cancelSelection();
        return;
      }

      // Check if valid target using isometric-aware adjacency
      const targets = this.getValidTargets(this.selectedCell.q, this.selectedCell.r);
      const isValidTarget = targets.some(n => n.q === cell.q && n.r === cell.r);

      // Cannot move to own cells - only attack enemy or capture empty
      if (cell.getOwner() === this.currentPlayer) {
        // Select different own cell instead
        if (cell.getStrength() > 1) {
          this.selectedCell = cell;
          this.updateUI();
          this.render();
        }
        return;
      }

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

  handleMouseMove(e) {
    // Could add hover effects 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) {
      // Attack empty or enemy cell
      let defenseStrength = defender.getStrength();
      
      if (defenseStrength > 0) {
        // Combat! Roll dice
        const attackRoll = Math.floor(Math.random() * attackStrength) + 1;
        const defenseRoll = Math.floor(Math.random() * defenseStrength) + 1;
        
        this.log(`Attack: ${attackStrength} vs ${defenseStrength} | Roll: ${attackRoll} vs ${defenseRoll}`);
        
        if (attackRoll > defenseRoll) {
          // Attacker wins
          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 cell with strength ${remainingStrength}`, 'victory');
          }
        } else {
          // Defender wins
          const remainingDefense = defenseRoll - attackRoll;
          defender.setStrength(Math.max(1, remainingDefense));
          this.log(`Attack repelled! Defender has ${Math.max(1, remainingDefense)} strength`, 'defeat');
        }
      } else {
        // Move to empty cell - transfer attackStrength (original - 1)
        attacker.setStrength(1);
        defender.setStrength(attackStrength);
        this.map.setOwner(defender.q, defender.r, this.currentPlayer);
        this.log(`Moved to 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();
  }

  endTurn() {
    if (this.gamePhase !== 'movement') return;
    
    // Apply supply
    const supply = this.map.calculateSupply(this.currentPlayer);
    this.distributeSupply(supply);
    
    this.log(`Player ${this.currentPlayer} received ${supply} supply`);
    
    // Switch player
    this.currentPlayer = this.currentPlayer === 1 ? 2 : 1;
    this.hasMoved = false;
    
    this.cancelSelection();
    this.updateUI();
    this.render();
    
    this.log(`Player ${this.currentPlayer}'s turn`);
  }

  distributeSupply(supply) {
    const playerCells = this.map.getPlayerCells(this.currentPlayer);
    
    // Find cells that can receive more dice
    const eligibleCells = playerCells.filter(cell => !cell.isMaxStrength());
    
    if (eligibleCells.length === 0 || supply === 0) return;
    
    // Distribute supply randomly among eligible cells
    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) {
        const addStrength = Math.min(remainingSupply, 48 - currentStrength);
        const newStrength = currentStrength + addStrength;
        randomCell.setStrength(newStrength);
        remainingSupply -= addStrength;
      }
      
      if (randomCell.isMaxStrength()) {
        eligibleCells.splice(eligibleCells.indexOf(randomCell), 1);
      }
    }
  }

  updateUI() {
    // Update current player stats
    const currentCells = this.map.getPlayerCells(this.currentPlayer);
    const currentStrength = currentCells.reduce((sum, c) => sum + c.getStrength(), 0);
    const currentSupply = this.map.calculateSupply(this.currentPlayer);
    
    // Update player 1 card (only player for now)
    document.getElementById('player1-cells').textContent = currentCells.length;
    document.getElementById('player1-supply').textContent = currentSupply;
    document.getElementById('player1-strength').textContent = currentStrength;
    
    // Update game info
    document.getElementById('current-turn').textContent = this.currentPlayer;
    document.getElementById('game-phase').textContent = this.gamePhase;
    
    // Update instruction
    const instruction = document.getElementById('action-instruction');
    if (this.selectedCell) {
      instruction.textContent = `Select target to attack (strength: ${this.selectedCell.getStrength()})`;
    } else {
      instruction.textContent = 'Select a cell with dice to move';
    }
    
    // Update selected cell info - always show with placeholder if nothing selected
    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 = '-';
    }

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

    cancelBtn.disabled = !this.selectedCell;
    endTurnBtn.disabled = !this.hasMoved;
  }

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

  showMessage(message) {
    const overlay = document.getElementById('message-overlay');
    const messageEl = document.getElementById('overlay-message');
    messageEl.textContent = message;
    overlay.classList.add('visible');
    
    setTimeout(() => {
      overlay.classList.remove('visible');
    }, 2000);
  }
}

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