class InteractionSystem {
    constructor(scene) {
        this.scene = scene;
        this.iso = new IsometricUtils(48, 24);

        // Input listener setup (only once)
        this.scene.input.on('pointerdown', (pointer) => {
            if (pointer.button === 0) { // Left Click
                this.handleLeftClick(pointer);
            }
        });

        // Loot Array
        this.drops = [];
    }

    handleLeftClick(pointer) {
        if (!this.scene.player) return;

        // 1. Account for camera and offset
        const worldX = pointer.worldX - this.scene.terrainOffsetX;
        const worldY = pointer.worldY - this.scene.terrainOffsetY;

        // 2. Convert to Grid
        const gridPos = this.iso.toGrid(worldX, worldY);

        // 3. Check distance
        const playerPos = this.scene.player.getPosition();
        const dist = Phaser.Math.Distance.Between(playerPos.x, playerPos.y, gridPos.x, gridPos.y);

        // Allow interaction within radius of 2.5 tiles
        if (dist > 2.5) {
            console.log('Too far:', dist.toFixed(1));
            return;
        }

        console.log(`☝️ Clicked tile: ${gridPos.x},${gridPos.y}`);

        // DETERMINE TOOL / ACTION
        let activeTool = null;
        const uiScene = this.scene.scene.get('UIScene');
        const invSys = this.scene.inventorySystem;

        if (uiScene && invSys) {
            const selectedIdx = uiScene.selectedSlot;
            const slotData = invSys.slots[selectedIdx];
            if (slotData) activeTool = slotData.type;
        }

        // 0. Build Mode Override
        if (this.scene.buildingSystem && this.scene.buildingSystem.isBuildMode) {
            this.scene.buildingSystem.tryBuild(gridPos.x, gridPos.y);
            return; // Consume click
        }

        // 3.5 Check for NPC Click
        if (this.scene.npcs) {
            for (const npc of this.scene.npcs) {
                if (Math.abs(npc.gridX - gridPos.x) < 2.5 && Math.abs(npc.gridY - gridPos.y) < 2.5) {
                    console.log(`🗣️ Interact with NPC: ${npc.type}`);

                    if (npc.type === 'zombie') {
                        // Taming Logic
                        npc.toggleState();
                        return; // Done
                    }

                    if (npc.type === 'merchant') {
                        // Open Trade Menu
                        if (uiScene && invSys) {
                            uiScene.showTradeMenu(invSys);
                        }
                        return; // Stop processing
                    }
                    return; // Stop processing other clicks (farming/terrain) if clicked NPC
                }
            }
        }

        // 4. Try Farming Action (Tilling, Planting, Harvesting)
        if (this.scene.farmingSystem) {
            const didFarm = this.scene.farmingSystem.interact(gridPos.x, gridPos.y, activeTool);
            if (didFarm) {
                // Animation?
                return;
            }
        }

        // 5. Try damage decoration (fallback)
        // 5. Try damage or interact decoration
        if (this.scene.terrainSystem) {
            const id = `${gridPos.x},${gridPos.y}`;
            if (this.scene.terrainSystem.decorationsMap.has(id)) {
                const decor = this.scene.terrainSystem.decorationsMap.get(id);


                // Ruin Interaction - Town Restoration
                if (decor.type === 'ruin' || decor.type === 'ruin_borut') {
                    // Check if near
                    if (dist > 2.5) {
                        console.log('Ruin too far.');
                        return;
                    }

                    // Show Project Menu
                    const uiScene = this.scene.scene.get('UIScene');
                    if (uiScene) {
                        // Define requirements based on ruin type
                        let req = { reqWood: 100, reqStone: 50, reqGold: 50 };
                        let ruinName = "Borut's Smithy"; // Default
                        let npcType = 'merchant';

                        if (decor.type === 'ruin') {
                            ruinName = "Merchant House";
                            req = { reqWood: 50, reqStone: 30, reqGold: 30 };
                        }

                        uiScene.showProjectMenu(req, () => {
                            // On Contribute Logic
                            if (invSys) {
                                const hasWood = invSys.hasItem('wood', req.reqWood);
                                const hasStone = invSys.hasItem('stone', req.reqStone || 0);
                                const hasGold = invSys.hasItem('gold', req.reqGold || 0);

                                // Check all requirements
                                if (hasWood && hasStone && hasGold) {
                                    // Consume materials
                                    invSys.removeItem('wood', req.reqWood);
                                    invSys.removeItem('stone', req.reqStone);
                                    invSys.removeItem('gold', req.reqGold);
                                    invSys.updateUI();

                                    console.log(`🏗️ Restoring ${ruinName}...`);

                                    // Transform Ruin -> House
                                    this.scene.terrainSystem.removeDecoration(gridPos.x, gridPos.y);
                                    this.scene.terrainSystem.placeStructure(gridPos.x, gridPos.y, 'house');

                                    // Spawn NPC nearby
                                    const npc = new NPC(this.scene, gridPos.x + 1, gridPos.y + 1,
                                        this.scene.terrainOffsetX, this.scene.terrainOffsetY, npcType);
                                    this.scene.npcs.push(npc);

                                    // Increase friendship (hearts)
                                    if (this.scene.statsSystem) {
                                        this.scene.statsSystem.addFriendship(npcType, 10); // +10 hearts
                                    }

                                    console.log(`✅ ${ruinName} Restored! +10 ❤️ Friendship`);

                                    // Play build sound
                                    if (this.scene.soundManager) this.scene.soundManager.playBuild();
                                } else {
                                    // Not enough materials
                                    const missing = [];
                                    if (!hasWood) missing.push(`${req.reqWood} Wood`);
                                    if (!hasStone) missing.push(`${req.reqStone} Stone`);
                                    if (!hasGold) missing.push(`${req.reqGold} Gold`);

                                    console.log(`❌ Not enough materials! Need: ${missing.join(', ')}`);
                                    alert(`Potrebuješ še: ${missing.join(', ')} da obnoviš ${ruinName}.`);
                                }
                            }
                        });
                    }
                    return; // Don't damage it
                }
            }

            const result = this.scene.terrainSystem.damageDecoration(gridPos.x, gridPos.y, 1);

            if (result === 'destroyed') {
                // Play chop sound
                if (this.scene.soundManager) this.scene.soundManager.playChop();

                // Spawn loot
                this.spawnLoot(gridPos.x, gridPos.y, 'wood');
            } else if (result === 'hit') {
                // Play hit sound
                if (this.scene.soundManager) this.scene.soundManager.playChop();
            }
        }
    }

    spawnLoot(gridX, gridY, type) {
        console.log(`🎁 Spawning ${type} at ${gridX},${gridY}`);

        // Convert to Screen
        const screenPos = this.iso.toScreen(gridX, gridY);
        const x = screenPos.x + this.scene.terrainOffsetX;
        const y = screenPos.y + this.scene.terrainOffsetY;

        // Create simplistic item drop sprite
        let symbol = '?';
        if (type === 'wood') symbol = '🪵';
        if (type === 'seeds') symbol = '🌱';
        if (type === 'wheat') symbol = '🌾';
        if (type === 'hoe') symbol = '🛠️';

        const drop = this.scene.add.text(x, y - 20, symbol, { fontSize: '20px' });
        drop.setOrigin(0.5);
        drop.setDepth(this.iso.getDepth(gridX, gridY) + 500); // above tiles

        // Bounce animation
        this.scene.tweens.add({
            targets: drop,
            y: y - 40,
            duration: 500,
            yoyo: true,
            ease: 'Sine.easeOut',
            repeat: -1
        });

        this.drops.push({
            gridX,
            gridY,
            sprite: drop,
            type: type
        });
    }

    update() {
        // Check for player pickup
        if (!this.scene.player) return;

        const playerPos = this.scene.player.getPosition();

        // Filter drops to pick up
        for (let i = this.drops.length - 1; i >= 0; i--) {
            const drop = this.drops[i];

            // Check if player is ON the drop tile
            if (Math.abs(drop.gridX - playerPos.x) < 0.8 && Math.abs(drop.gridY - playerPos.y) < 0.8) {
                // Pick up!
                console.log('🎒 Picked up:', drop.type);

                // Play pickup sound
                if (this.scene.soundManager) this.scene.soundManager.playPickup();

                // Add to inventory
                if (this.scene.inventorySystem) {
                    this.scene.inventorySystem.addItem(drop.type, 1);
                }

                // Destroy visual
                drop.sprite.destroy();
                this.drops.splice(i, 1);
            }
        }
    }
}