app/services/workflow_manager.py

import json
import os
import logging
import random

logger = logging.getLogger(__name__)

class WorkflowManager:
    def __init__(self, workflows_dir="templates/workflows"):
        self.workflows_dir = workflows_dir

    def load_workflow(self, workflow_filename):
        """
        templates/workflows/ 폴더 내의 JSON 파일을 로드하는 함수.
        """
        file_path = os.path.join(self.workflows_dir, workflow_filename)
        if not file_path.endswith('.json'):
            file_path += '.json'
            
        try:
            with open(file_path, 'r', encoding='utf-8') as f:
                return json.load(f)
        except Exception as e:
            logger.error(f"Error loading workflow {workflow_filename}: {e}")
            return None

    def build_workflow(self, workflow_json, prompt_text=None, negative_prompt=None, seed=None, 
                       image_path=None, checkpoint_name=None, width=None, height=None):
        """
        워크플로우 내의 특정 노드들을 찾아 값을 치환하는 함수.
        
        1. CLIP Text Encode (Positive/Negative)
        2. KSampler (Seed)
        3. Load Image (Image path)
        4. Checkpoint Loader (Model name)
        5. Empty Latent Image (Width/Height)
        """
        # 워크플로우 복사본 생성 (원본 유지)
        wf = json.loads(json.dumps(workflow_json))
        
        for node_id, node in wf.items():
            class_type = node.get("class_type")
            inputs = node.get("inputs", {})

            # 1. CLIP Text Encode (프롬프트 치환)
            if class_type == "CLIPTextEncode":
                if prompt_text and "text" in inputs and "positive" in str(node.get("_meta", {}).get("title", "")).lower():
                    inputs["text"] = prompt_text
                elif negative_prompt and "text" in inputs and "negative" in str(node.get("_meta", {}).get("title", "")).lower():
                    inputs["text"] = negative_prompt
                # 타이틀이 없는 경우 일반적인 텍스트 노드 처리
                elif prompt_text and "text" in inputs:
                    inputs["text"] = prompt_text

            # 2. KSampler (시드 치환)
            elif class_type == "KSampler":
                if seed is not None:
                    inputs["seed"] = seed
                else:
                    # 시드가 지정되지 않은 경우 랜덤 생성
                    inputs["seed"] = random.randint(0, 0xffffffffffffffff)

            # 3. Load Image (참조 이미지 경로 치환)
            elif class_type == "LoadImage":
                if image_path:
                    inputs["image"] = image_path

            # 4. Checkpoint Loader (모델 경로 치환 - 나노바나나, Z-image 등)
            elif class_type in ["CheckpointLoaderSimple", "CheckpointLoader"]:
                if checkpoint_name:
                    inputs["ckpt_name"] = checkpoint_name

            # 5. Empty Latent Image (크기 치환)
            elif class_type == "EmptyLatentImage":
                if width:
                    inputs["width"] = width
                if height:
                    inputs["height"] = height

        return wf

    def get_available_workflows(self):
        """
        사용 가능한 워크플로우 목록을 반환합니다.
        """
        try:
            return [f for f in os.listdir(self.workflows_dir) if f.endswith('.json')]
        except Exception as e:
            logger.error(f"Error listing workflows: {e}")
            return []