import os
import json
from datetime import datetime, timedelta
import gradio as gr
import spaces

DATA_FILE = "messages.json"
UPLOAD_DIR = "uploads"
os.makedirs(UPLOAD_DIR, exist_ok=True)

# 保留留言的天數（設為 30 天）
RETENTION_DAYS = 30

def cleanup_old_messages(messages):
    """清理超過 Retention Days 的舊留言與對應圖片檔"""
    now = datetime.now()
    valid_messages = []
    
    for msg in messages:
        try:
            # 解析留言時間 (格式: YYYY-MM-DD HH:MM)
            msg_time = datetime.strptime(msg["time"], "%Y-%m-%d %H:%M")
            # 判斷是否在 30 天內
            if now - msg_time <= timedelta(days=RETENTION_DAYS):
                valid_messages.append(msg)
            else:
                # 已過期，刪除相關圖片實體檔案以釋放空間
                if msg.get("image") and os.path.exists(msg["image"]):
                    try:
                        os.remove(msg["image"])
                    except Exception as e:
                        print(f"刪除舊圖片失敗: {e}")
        except Exception:
            # 若時間解析失敗，預設留存
            valid_messages.append(msg)
            
    return valid_messages

def load_messages():
    if os.path.exists(DATA_FILE):
        with open(DATA_FILE, "r", encoding="utf-8") as f:
            try:
                messages = json.load(f)
                # 載入時自動執行一次清理
                cleaned_messages = cleanup_old_messages(messages)
                if len(cleaned_messages) != len(messages):
                    save_messages(cleaned_messages)
                return cleaned_messages
            except Exception:
                return []
    return []

def save_messages(messages):
    with open(DATA_FILE, "w", encoding="utf-8") as f:
        json.dump(messages, f, ensure_ascii=False, indent=2)

@spaces.GPU(duration=1)
def dummy_gpu_task():
    return True

def add_post(author, text, image):
    author = author.strip() if author and author.strip() else "匿名成員"
    
    img_path = None
    if image is not None:
        timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
        img_path = os.path.join(UPLOAD_DIR, f"{timestamp}.png")
        image.save(img_path)

    # 讀取並自動清理舊資料
    messages = load_messages()
    
    messages.insert(0, {
        "author": author,
        "text": text,
        "image": img_path,
        "time": datetime.now().strftime("%Y-%m-%d %H:%M")
    })
    
    # 儲存前再次確保只留 30 天內的資料
    messages = cleanup_old_messages(messages)
    save_messages(messages)
    
    return "", "", None, *get_board_data()

def get_board_data():
    messages = load_messages()
    text_logs = []
    gallery_images = []
    
    for msg in messages:
        text_logs.append(f"📌 {msg['author']}（{msg['time']}）\n{msg['text']}\n" + "—"*25)
        if msg.get('image') and os.path.exists(msg['image']):
            gallery_images.append((msg['image'], f"{msg['author']} 的分享 ({msg['time']})"))
            
    full_text = "\n\n".join(text_logs) if text_logs else "目前尚無留言（近 30 天）。"
    return full_text, gallery_images

with gr.Blocks(title="家庭佈告欄") as demo:
    gr.Markdown("# 🏡 家庭成員佈告欄")
    gr.Markdown("💡 *系統將自動保留最近 30 天內的留言與照片，過期內容會自動清除以清理空間。*")
    
    with gr.Row():
        with gr.Column():
            author_input = gr.Textbox(label="你的稱呼", placeholder="例如：媽媽、小明")
            text_input = gr.Textbox(label="留言內容", lines=3, placeholder="想跟大家說什麼？")
            image_input = gr.Image(label="上傳照片（可選）", type="pil")
            submit_btn = gr.Button("發布動態", variant="primary")
            
        with gr.Column():
            init_text, init_gallery = get_board_data()
            board_text = gr.Textbox(value=init_text, label="留言記錄（近30天）", lines=8, interactive=False)
            board_gallery = gr.Gallery(value=init_gallery, label="照片牆")
            refresh_btn = gr.Button("🔄 重新整理")

    submit_btn.click(
        fn=add_post,
        inputs=[author_input, text_input, image_input],
        outputs=[author_input, text_input, image_input, board_text, board_gallery]
    )
    refresh_btn.click(
        fn=get_board_data,
        outputs=[board_text, board_gallery]
    )

demo.launch()