novafarma/src/systems/GemDropSystem.js

/**
 * GEM DROP SYSTEM
 * Handles rare gem drops from enemies, mining, etc.
 * Gems: Diamond, Emerald, Ruby (high value items for selling)
 */

class GemDropSystem {
    constructor(scene) {
        this.scene = scene;

        // Gem definitions with rarity and value
        this.gems = {
            'diamond': {
                name: 'Diamond',
                rarity: 'legendary', // 0.5% drop
                value: 500, // Sell price in gold
                icon: '💎'
            },
            'emerald': {
                name: 'Emerald',
                rarity: 'epic', // 2% drop
                value: 200,
                icon: '💚'
            },
            'ruby': {
                name: 'Ruby',
                rarity: 'rare', // 5% drop
                value: 100,
                icon: '❤️'
            },
            'sapphire': {
                name: 'Sapphire',
                rarity: 'uncommon', // 10% drop
                value: 50,
                icon: '💙'
            }
        };

        // Drop chance by rarity
        this.rarityChances = {
            'legendary': 0.005,  // 0.5%
            'epic': 0.02,       // 2%
            'rare': 0.05,       // 5%
            'uncommon': 0.10    // 10%
        };
    }

    /**
     * Roll for gem drop from enemy/resource
     * @param {string} source - 'zombie', 'elite', 'stone_ore', 'iron_ore'
     * @param {number} x - Grid X
     * @param {number} y - Grid Y
     * @param {number} luckBonus - Player luck modifier (0-1)
     */
    rollGemDrop(source, x, y, luckBonus = 0) {
        const dropTable = this.getDropTableForSource(source);
        if (!dropTable || dropTable.length === 0) return;

        // Roll for each possible gem
        for (const gemEntry of dropTable) {
            const gemType = gemEntry.gem;
            const gem = this.gems[gemType];
            if (!gem) continue;

            const baseChance = this.rarityChances[gem.rarity];
            const finalChance = baseChance * (1 + luckBonus);

            if (Math.random() < finalChance) {
                // GEM DROPPED!
                console.log(`💎 RARE DROP: ${gem.name} from ${source}!`);
                this.spawnGem(gemType, x, y);

                // Play special sound/effect
                if (this.scene.particleEffects) {
                    this.scene.particleEffects.gemSparkle(x, y, gem.icon);
                }
                if (this.scene.soundManager) {
                    this.scene.soundManager.playRareDrop();
                }

                // Only drop 1 gem per source
                break;
            }
        }
    }

    /**
     * Get drop table based on source
     */
    getDropTableForSource(source) {
        const tables = {
            'zombie': [
                { gem: 'sapphire', weight: 1 }
            ],
            'elite_zombie': [
                { gem: 'ruby', weight: 2 },
                { gem: 'emerald', weight: 1 }
            ],
            'troll': [
                { gem: 'emerald', weight: 2 },
                { gem: 'diamond', weight: 0.5 }
            ],
            'stone_ore': [
                { gem: 'sapphire', weight: 1 }
            ],
            'iron_ore': [
                { gem: 'ruby', weight: 1 }
            ],
            'gold_ore': [
                { gem: 'emerald', weight: 1.5 },
                { gem: 'diamond', weight: 0.3 }
            ],
            'boss': [
                { gem: 'diamond', weight: 5 } // Guaranteed almost!
            ]
        };

        return tables[source] || [];
    }

    /**
     * Spawn gem as loot item
     */
    spawnGem(gemType, gridX, gridY) {
        if (this.scene.lootSystem) {
            this.scene.lootSystem.spawnLoot(gridX, gridY, gemType, 1);
        } else {
            console.warn('⚠️ LootSystem not found - gem cannot spawn!');
        }

        // Show floating text
        const gem = this.gems[gemType];
        if (this.scene.events) {
            const screenPos = this.scene.terrainSystem.iso.toScreen(gridX, gridY);
            this.scene.events.emit('show-floating-text', {
                x: screenPos.x,
                y: screenPos.y - 50,
                text: `${gem.icon} ${gem.name}!`,
                color: '#ff00ff', // Purple for rare
                size: '20px'
            });
        }
    }

    /**
     * Get gem sell value
     */
    getGemValue(gemType) {
        const gem = this.gems[gemType];
        return gem ? gem.value : 0;
    }

    /**
     * Sell gem to merchant
     */
    sellGem(gemType, amount, playerInventory) {
        const gem = this.gems[gemType];
        if (!gem) {
            console.warn('⚠️ Unknown gem type:', gemType);
            return 0;
        }

        // Check if player has gem
        const hasAmount = playerInventory.getItemCount(gemType);
        if (hasAmount < amount) {
            console.warn(`⚠️ Not enough ${gem.name} to sell!`);
            return 0;
        }

        // Calculate total value
        const totalValue = gem.value * amount;

        // Remove from inventory
        playerInventory.removeItem(gemType, amount);

        // Add gold
        playerInventory.addItem('gold_coin', totalValue);

        console.log(`💰 Sold ${amount}x ${gem.name} for ${totalValue} gold`);
        return totalValue;
    }
}

// Export
if (typeof module !== 'undefined' && module.exports) {
    module.exports = GemDropSystem;
}