from fastapi import FastAPI, UploadFile, File, Form, Depends, HTTPException, status
from fastapi.security import OAuth2PasswordBearer
from PIL import Image
from sqlalchemy.orm import Session
from sqlalchemy import func
from fastapi. middleware.cors import CORSMiddleware
from datetime import datetime,timedelta
from pydantic import BaseModel
from typing import List
from datetime import date as date_type,timedelta
import os
import uuid
import io
from app.core.config import settings
from app.core.email import send_reset_code,send_support_email
from app.core.utils import validate_email,validate_password,generate_code
from app.core.security import decode_access_token, hash_password, verify_password, create_access_token
from app.db.models import User, History,PasswordReset,WeightLog
from app.db.database import Base, engine, SessionLocal
from app.services.nutrition_estimator import NutritionEstimator
from app.core.totp import (
    generate_totp_secret,
    generate_qr_code,
    verify_totp_code,
    get_current_totp_code
)

Base.metadata.create_all(bind=engine)

def get_db():
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()

oauth2_scheme = OAuth2PasswordBearer(tokenUrl="login")

def get_current_user(token: str = Depends(oauth2_scheme), db: Session = Depends(get_db)):
    payload = decode_access_token(token)
    if not payload:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Invalid authentication credentials",
        )
    if payload.get("temp"):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Temporary token not allowed.  Please complete 2FA verification.",
            headers={"WWW-Authenticate": "Bearer"},
        )
    username = payload.get("sub")
    if not username:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Invalid authentication credentials",
        )
    user = db.query(User).filter(User.username == username).first()
    if not user:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="User not found",
        )
    return user

app = FastAPI()

cors_origins = os.getenv("CORS_ORIGINS", "http://localhost:5173").split(",")
app.add_middleware(
    CORSMiddleware,
    allow_origins=cors_origins,
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

try:
    nutrition_estimator=NutritionEstimator()
except Exception as e:
    print(f"Warning: Nutrition Estimator failed to initialize: {e}")
    nutrition_estimator=None

@app.get("/")
def root():
    return {"message": "Food AI API is running"}
@app.post("/register")
def register(username:str=Form(...),password:str=Form(...),email:str=Form(...),db:Session=Depends(get_db)):
    if not validate_email(email):
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Invalid email format."
        )

    is_valid, error_message = validate_password(password)
    if not is_valid:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=error_message
        )

    existing_user=db.query(User).filter(User.username==username).first()
    if existing_user:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Username already registered."
        )

    existing_email=db.query(User).filter(User.email==email).first()
    if existing_email:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Email already registered."
        )

    hashed_password=hash_password(password)
    user=User(username=username,email=email,hashed_password=hashed_password)
    db.add(user)
    db.commit()
    db.refresh(user)
    return {"message": "User created successfully"}

@app.post("/login")
def login(username:str=Form(...),password:str=Form(...),db:Session=Depends(get_db)):
    user=db.query(User).filter(User.username==username).first()
    if not user:
        user=db.query(User).filter(User.email==username).first()

    if not user or not verify_password(password,user.hashed_password):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Incorrect username/email or password"
        )

    if user.is_2fa_enabled:
        temp_token=create_access_token(
            data={"sub":user.username,"temp":True},
            expires_delta=timedelta(minutes=5)
        )
        return {
            "requires_2fa":True,
            "temp_token":temp_token,
            "message":"Please provide 2FA code"
        }

    access_token=create_access_token(data={"sub":user.username})
    return {"access_token":access_token,"token_type":"bearer"}

@app.post("/login/2fa")
def login_2fa(temp_token:str=Form(...),code:str=Form(...),db:Session=Depends(get_db)):
    payload=decode_access_token(temp_token)
    if not payload or not payload.get("temp"):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Invalid or expired temporary token"
        )
    username=payload.get("sub")
    if not username:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Invalid token"
        )
    user=db.query(User).filter(User.username==username).first()
    if not user:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="User not found"
        )
    if not user.is_2fa_enabled:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="2FA is not enabled for this account"
        )
    if not verify_totp_code(user.totp_secret,code):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Invalid 2FA code"
        )
    access_token=create_access_token(data={"sub":user.username})
    return {"access_token": access_token, "token_type": "bearer"}

@app.post("/forgot-password")
def forgot_password(email:str=Form(...),db:Session=Depends(get_db)):
    if not validate_email(email):
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Invalid email format."
        )

    user=db.query(User).filter(User.email==email).first()
    if not user:
        return {
            "message": "If this email exists, a reset code has been sent.",
            "email": email
        }
    reset_code=generate_code()
    expires_at=datetime.utcnow()+timedelta(minutes=settings.RESET_CODE_EXPIRE_MINUTES)
    db.query(PasswordReset).filter(PasswordReset.user_id==user.id,PasswordReset.is_used==0).delete()
    password_reset=PasswordReset(user_id=user.id,reset_code=reset_code,expires_at=expires_at,is_used=0)
    db.add(password_reset)
    db.commit()
    email_sent=send_reset_code(user.email,reset_code)
    if not email_sent:
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail="Failed to send email.  Please try again later."
        )
    return {
        "message": "Reset code sent to your email.",
        "email": email,
        "expires_in_minutes": settings.RESET_CODE_EXPIRE_MINUTES
    }

@app.post("/reset-password")
def reset_password(email:str=Form(...),reset_code:str=Form(...),new_password:str=Form(...),db:Session=Depends(get_db)):
    user=db.query(User).filter(User.email==email).first()
    if not user:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Invalid email or reset code."
        )
    reset_entry=db.query(PasswordReset).filter(PasswordReset.user_id==user.id,PasswordReset.reset_code==reset_code,PasswordReset.is_used==0).first()
    if not reset_entry:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Invalid or expired reset code."
        )
    if datetime.utcnow() > reset_entry.expires_at:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Reset code has expired.  Please request a new one."
        )
    is_valid, error_message = validate_password(new_password)
    if not is_valid:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=error_message
        )
    user.hashed_password=hash_password(new_password)
    reset_entry.is_used = 1
    db.commit()
    return {
        "message": "Password reset successfully.",
        "email": email
    }

@app.post("/2fa/enable")
def enable_2fa(db:Session=Depends(get_db),current_user:User=Depends(get_current_user)):
    if current_user.is_2fa_enabled:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="2FA is already enabled for this account."
        )
    secret=generate_totp_secret()
    current_user.totp_secret=secret
    db.commit()
    qr_code=generate_qr_code(username=current_user.email,secret=secret,issuer="CalorieTrackerAi")
    return {
        "message": "Scan the QR code with Google Authenticator",
        "qr_code": qr_code,
        "instructions": [
            "1. Install Google Authenticator on your phone",
            "2. Open the QR code URL in browser",
            "3. Scan the QR code with Google Authenticator",
            "4. Enter the 6-digit code to confirm"
        ]
    }

@app.post("/2fa/disable")
def disable_2fa(db:Session=Depends(get_db),current_user:User=Depends(get_current_user),code:str=Form(...)):
    if not current_user.is_2fa_enabled:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="2FA is not enabled for this account."
        )
    if not verify_totp_code(current_user.totp_secret, code):
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Invalid verification code."
        )
    current_user.is_2fa_enabled=False
    current_user.totp_secret=None
    db.commit()
    return {
        "message": "2FA disabled successfully.",
        "email": current_user.email
    }

@app.post("/2fa/verify")
def verify_2fa(db:Session=Depends(get_db),code:str=Form(...),current_user:User=Depends(get_current_user)):
    if not current_user.totp_secret:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="2FA setup not initiated.  Call /2fa/enable first."
        )
    if current_user.is_2fa_enabled:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="2FA is already enabled."
        )
    if not verify_totp_code(current_user.totp_secret, code):
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Invalid verification code."
        )
    current_user.is_2fa_enabled=True
    db.commit()
    return {
        "message": "2FA enabled successfully! ",
        "email": current_user.email
    }

@app.post("/predict")
async def predict(file: UploadFile=File(...),db:Session=Depends(get_db),current_user:User=Depends(get_current_user)):
    try:
        if nutrition_estimator is None:
            raise HTTPException(
                status_code=500,
                detail="Nutrition analysis not available"
            )
        contents = await file.read()
        allowed_extensions = {'png','jpg','jpeg','gif','bmp'}
        file_ext = file.filename.rsplit('.', 1)[1].lower() if '.' in file.filename else ''
        if file_ext not in allowed_extensions:
            raise HTTPException(
                status_code=400,
                detail=f"Invalid file type.Allowed: {', '.join(allowed_extensions)}"
            )
        upload_folder='uploads'
        os.makedirs(upload_folder,exist_ok=True)
        unique_filename=f"{uuid.uuid4()}_{file.filename}"
        temp_path=os.path.join(upload_folder,unique_filename)
        with open(temp_path,'wb') as f:
            f.write(contents)
        try:
            from starlette.concurrency import run_in_threadpool
            result = await run_in_threadpool(nutrition_estimator.analyze_image, temp_path)
            if result is None:
                raise HTTPException(
                    status_code=500,
                    detail="Analysis returned no result (internal error)"
                )
            try:
                os.remove(temp_path)
            except:
                pass
            if not result['success']:
                raise HTTPException(
                    status_code=500,
                    detail=f"Analysis failed: {result.get('error','Unknown error')}"
                )
            final_result=result["final_result"]
            final_foods=final_result["final_foods"]
            foods_list=[]
            for food_item in final_foods:
                food_name=food_item['name']
                nutrition=food_item.get('nutrition',{})
                if nutrition is None:
                    nutrition={}
                estimated_grams=nutrition.get('estimated_weight_grams',0) or 0
                estimated_calories=nutrition.get('calories_total',0) or 0
                macros=nutrition.get('macronutrients',{})
                if macros is None:
                    macros={}
                protein_g=macros.get('protein_g',0.0) or 0.0
                carbs_g=macros.get('carbs_g',0.0) or 0.0
                fat_g=macros.get('fat_g',0.0) or 0.0
                foods_list.append({"name":food_name,
                                "grams":estimated_grams,
                                "calories":estimated_calories,
                                "protein_g":protein_g,
                                "carbs_g":carbs_g,
                                "fat_g":fat_g})

            return {
                "success":True,
                "foods_detected":foods_list,
                "total_nutrition":final_result['total_nutrition'],
                "reconciliation_info":final_result['reconciliation_summary']
            }
        except HTTPException:
            raise
        except Exception as e:
            try:
                os.remove(temp_path)
            except:
                pass
            raise HTTPException(
                status_code=500,
                detail=f"Analysis failed: {str(e)}"
            )
    except HTTPException:
        raise
    except Exception as e:
        raise HTTPException(
            status_code=500,
            detail=f"Server error: {str(e)}"
        )

class FoodItemInput(BaseModel):
    name:str
    grams:int
    calories:float
    protein_g:float
    carbs_g:float
    fat_g:float

class SaveMealRequest(BaseModel):
    foods:List[FoodItemInput]
    meal_type:str
    meal_time:str
    log_date:str

@app.post("/history/save")
def save_meal(request:SaveMealRequest,db:Session=Depends(get_db),current_user:User=Depends(get_current_user)):
    try:
        valid_meal_types=["Breakfast","Lunch","Snack","Dinner"]
        if request.meal_type not in valid_meal_types:
            raise HTTPException(
                status_code=400,
                detail=f"Invalid meal_type. Must be one of: {', '.join(valid_meal_types)}"
            )
        try:
            log_date = datetime.fromisoformat(request.log_date)
        except ValueError:
            raise HTTPException(
                status_code=400,
                detail="Invalid log_date format. Use ISO format: YYYY-MM-DD"
            )
        saved_items=[]
        for food in request.foods:
            history=History(
                label=food.name,
                grams=food.grams,
                calories=food.calories,
                protein_g=food.protein_g,
                carbs_g=food.carbs_g,
                fat_g=food.fat_g,
                meal_type=request.meal_type,
                meal_time=request.meal_time,
                log_date=log_date,
                user_id=current_user.id
            )
            db.add(history)
            saved_items.append({
                "name": food.name,
                "grams": food.grams,
                "calories": food.calories
            })
        db.commit()
        return {
            "success": True,
            "message": f"Meal logged successfully ({len(saved_items)} items)",
            "meal_type": request.meal_type,
            "meal_time": request.meal_time,
            "log_date": request.log_date,
            "items_saved": len(saved_items),
            "foods": saved_items
        }
    except HTTPException:
        raise
    except Exception as e:
        db.rollback()
        raise HTTPException(
            status_code=500,
            detail=f"Failed to save meal: {str(e)}"
        )

@app.get("/history")
def get_history(date:str=None,db:Session=Depends(get_db),current_user=Depends(get_current_user)):
    query=db.query(History).filter(History.user_id==current_user.id)
    if date:
        try:
            target_date=datetime.fromisoformat(date)
            query=query.filter(func.date(History.log_date)==target_date.date())
        except ValueError:
            raise HTTPException(
                status_code=400,
                detail="Invalid date format. Use YYYY-MM-DD"
            )
    history = query.order_by(History.created_at.desc()).all()
    return {
        "success": True,
        "count": len(history),
        "date_filter": date if date else "all",
        "history": history
    }

class UpdateMealRequest(BaseModel):
    grams:     int
    calories:  float
    protein_g: float
    carbs_g:   float
    fat_g:     float

@app.put("/history/item/{meal_id}")
def update_meal(meal_id:int,request:UpdateMealRequest,db:Session=Depends(get_db),current_user: User = Depends(get_current_user)):
    meal=db.query(History).filter(History.id==meal_id,History.user_id==current_user.id).first()
    if not meal:
        raise HTTPException(
            status_code=404,
            detail="Meal not found"
        )
    meal.grams = request.grams
    meal.calories = request.calories
    meal.protein_g = request.protein_g
    meal.carbs_g = request.carbs_g
    meal.fat_g = request.fat_g
    db.commit()
    db.refresh(meal)
    return {
        "success": True,
        "message": "Meal updated successfully",
        "id": meal.id
    }

@app.delete("/history/item/{meal_id}")
def update_meal(meal_id:int,db:Session=Depends(get_db),current_user: User = Depends(get_current_user)):
    meal = db.query(History).filter(History.id == meal_id, History.user_id == current_user.id).first()
    if not meal:
        raise HTTPException(
            status_code=404,
            detail="Meal not found"
        )
    db.delete(meal)
    db.commit()
    return {
        "success":True,
        "message":"Meal deleted successfully",
        "id":meal_id
    }

class UpdateProfileRequest(BaseModel):
    full_name:str|None=None
    age:int | None = None
    gender:str |None = None
    height_cm: float| None = None
    weight_kg:float| None = None
    activity_level:str | None = None
    username:str | None = None
    email:str|None = None
    goal_type:str|None = None
    calorie_goal_mode:str|None = None
    calorie_goal_manual:float|None = None
    weight_goal_kg: float |None = None

@app.get("/profile")
def get_profile(current_user:User=Depends(get_current_user)):
    return{"success":True,
        "id":current_user.id,
        "username":current_user.username,
        "email":current_user.email,
        "full_name":current_user.full_name,
        "age":current_user.age,
        "gender":current_user.gender,
        "height_cm":current_user.height_cm,
        "weight_kg":current_user.weight_kg,
        "activity_level":current_user.activity_level,
        "goal_type": current_user.goal_type,
        "calorie_goal_mode": current_user.calorie_goal_mode,
        "calorie_goal_manual": current_user.calorie_goal_manual,
        "weight_goal_kg": current_user.weight_goal_kg,
        "is_2fa_enabled":current_user.is_2fa_enabled,
        "setup_completed":current_user.setup_completed,
    }

@app.put("/profile")
def update_profile(request:UpdateProfileRequest,db:Session=Depends(get_db),current_user:User=Depends(get_current_user)):
    if request.username and request.username!=current_user.username:
        existing=db.query(User).filter(User.username==request.username).firt()
        if existing:
            raise HTTPException(status_code=400, detail="Username already taken.")
        current_user.username = request.username

    if request.email and request.email != current_user.email:
        if not validate_email(request.email):
            raise HTTPException(status_code=400, detail="Invalid email format.")
        existing = db.query(User).filter(User.email == request.email).first()
        if existing:
            raise HTTPException(status_code=400, detail="Email already taken.")
        current_user.email = request.email

    old_goal_type = current_user.goal_type

    if request.full_name is not None: current_user.full_name = request.full_name
    if request.age is not None: current_user.age = request.age
    if request.gender is not None: current_user.gender = request.gender
    if request.height_cm is not None: current_user.height_cm = request.height_cm
    if request.activity_level is not None: current_user.activity_level = request.activity_level
    if request.goal_type is not None: current_user.goal_type = request.goal_type
    if request.calorie_goal_mode is not None: current_user.calorie_goal_mode = request.calorie_goal_mode
    if request.calorie_goal_manual is not None: current_user.calorie_goal_manual = request.calorie_goal_manual
    if request.weight_goal_kg is not None: current_user.weight_goal_kg = request.weight_goal_kg

    if request.weight_kg is not None:
        current_user.weight_kg = request.weight_kg
        today = date_type.today()
        existing = db.query(WeightLog).filter(
            WeightLog.user_id == current_user.id,
            WeightLog.date == today
        ).first()

        if existing:
            existing.weight_kg = request.weight_kg
        else:
            db.add(WeightLog(
                user_id=current_user.id,
                date=today,
                weight_kg=request.weight_kg
            ))

    if request.goal_type is not None and request.goal_type != old_goal_type:
        current_user.start_weight = current_user.weight_kg
        today = date_type.today()
        existing = db.query(WeightLog).filter(
            WeightLog.user_id == current_user.id,
            WeightLog.date == today
        ).first()
        if existing:
            existing.weight_kg = current_user.weight_kg
        else:
            db.add(WeightLog(user_id=current_user.id, date=today, weight_kg=current_user.weight_kg))

    db.commit()
    db.refresh(current_user)

    return {
        "success": True,
        "message": "Profile updated successfully",
        "username": current_user.username,
        "email": current_user.email,
        "full_name": current_user.full_name,
        "age": current_user.age,
        "gender": current_user.gender,
        "height_cm": current_user.height_cm,
        "weight_kg": current_user.weight_kg,
        "activity_level": current_user.activity_level,
    }

@app.post("/support")
def send_support_message(message:str=Form(...),current_user:User=Depends(get_current_user),db:Session=Depends(get_db)):
    if not message.strip():
        raise HTTPException(
            status_code=400,
            detail="Message cannot be empty."
        )
    email_sent=send_support_email(user_email=current_user.email,username=current_user.username,message=message)
    if not email_sent:
        raise HTTPException(
            status_code=500,
            detail="Failed to send message. Please try again later."
        )
    return {"success": True, "message": "Message sent successfully!"}

class SetupRequest(BaseModel):
    age:int
    gender:str
    weight_kg:float
    height_cm:float
    activity_level:str
    goal_type:str
    weight_goal_kg:float|None=None

@app.post('/setup/complete')
def complete_setup(request: SetupRequest,db: Session = Depends(get_db),current_user: User = Depends(get_current_user)):
    if request.gender not in ['male', 'female']:
        raise HTTPException(status_code=400, detail="Invalid gender.")
    if request.activity_level not in ['sedentary', 'light', 'moderate', 'active']:
        raise HTTPException(status_code=400, detail="Invalid activity level.")
    if request.goal_type not in ['lose', 'maintain', 'gain']:
        raise HTTPException(status_code=400, detail="Invalid goal type.")
    if request.goal_type in ['lose', 'gain'] and not request.weight_goal_kg:
        raise HTTPException(status_code=400, detail="Target weight is required for this goal.")

    current_user.age = request.age
    current_user.gender = request.gender
    current_user.weight_kg = request.weight_kg
    current_user.height_cm = request.height_cm
    current_user.activity_level = request.activity_level
    current_user.goal_type = request.goal_type
    current_user.weight_goal_kg = request.weight_goal_kg
    current_user.start_weight=request.weight_kg
    current_user.setup_completed = True

    first_log=WeightLog(user_id=current_user.id,
                        weight_kg=request.weight_kg,
                        date=date_type.today(),)
    db.add(first_log)
    db.commit()

    return{"success":True,"message":"Setup completed successfully!"}

@app.post("/weight-log")
def add_weight_log(weight_kg:float=Form(...),db:Session=Depends(get_db),current_user:User=Depends(get_current_user)):
    if weight_kg < 20 or weight_kg > 300:
        raise HTTPException(status_code=400, detail="Invalid weight value.")
    today = date_type.today()
    existing=db.query(WeightLog).filter(WeightLog.user_id==current_user.id,WeightLog.date==today).first()
    if existing:
        existing.weight_kg=weight_kg
    else:
        log=WeightLog(user_id=current_user.id,
            weight_kg=weight_kg,
            date=today,
        )
        db.add(log)
    current_user.weight_kg=weight_kg
    db.commit()

    return {"success": True, "message": "Weight logged successfully!", "weight_kg": weight_kg}

@app.get("/progress")
def get_progress(db:Session=Depends(get_db),current_user:User=Depends(get_current_user)):
    def calculate_tdee(user):
        if not user.weight_kg or not user.height_cm or not user.age or not user.gender:
            return 2000
        if user.gender == 'male':
            bmr = 10 * user.weight_kg + 6.25 * user.height_cm - 5 * user.age + 5
        else:
            bmr = 10 * user.weight_kg + 6.25 * user.height_cm - 5 * user.age - 161
        multipliers = {
            'sedentary': 1.2,
            'light': 1.375,
            'moderate': 1.55,
            'active': 1.725,
        }
        tdee = bmr * multipliers.get(user.activity_level, 1.2)
        if user.goal_type == 'lose':
            tdee -= 500
        elif user.goal_type == 'gain':
            tdee += 300
        return round(tdee)

    if current_user.calorie_goal_mode == 'manual' and current_user.calorie_goal_manual:
        calorie_goal = current_user.calorie_goal_manual
    else:
        calorie_goal = calculate_tdee(current_user)

    weight_logs = db.query(WeightLog).filter(
        WeightLog.user_id == current_user.id
    ).order_by(WeightLog.date.asc()).all()

    start_weight=current_user.start_weight or current_user.weight_kg or 0
    current_weight = weight_logs[-1].weight_kg if weight_logs else (current_user.weight_kg or 0)
    goal_weight=current_user.weight_goal_kg
    goal_type=current_user.goal_type or 'maintain'

    if goal_type=='lose' and goal_weight:
        total=round(start_weight - goal_weight, 1)
        changed=round(start_weight - current_weight, 1)
        remaining=round(current_weight - goal_weight, 1)
        progress=round((changed / total * 100), 1) if total > 0 else 0

    elif goal_type=='gain' and goal_weight:
        total=round(goal_weight - start_weight, 1)
        changed=round(current_weight - start_weight, 1)
        remaining=round(goal_weight - current_weight, 1)
        progress=round((changed / total * 100), 1) if total > 0 else 0

    else:
        total=0
        changed=0
        remaining=0
        progress=100

    all_history=db.query(History).filter(History.user_id==current_user.id).order_by(History.log_date.asc()).all()
    distinct_days=len(set(h.log_date.date() for h in all_history if h.log_date))
    today=date_type.today()
    streak=0
    check_day=today
    logged_days=set(h.log_date.date() for h in all_history)
    while check_day in logged_days:
        streak+=1
        check_day-=timedelta(days=1)

    if all_history:
        total_cals=sum(h.calories or 0 for h in all_history)
        avg_calories=round(total_cals / distinct_days) if distinct_days>0 else 0
    else:
        avg_calories=0

    week_ago=today-timedelta(days=7)
    week_history=[h for h in all_history if h.log_date and h.log_date.date()>=week_ago]
    weekly_calories=sum(h.calories or 0 for h in week_history)

    week_days=len(set(h.log_date.date() for h in week_history if h.log_date))
    if week_days>0 and calorie_goal:
        avg_weekly_cal=weekly_calories/week_days
        daily_diff=avg_weekly_cal-calorie_goal
        weekly_change=round((daily_diff*7)/7700,2)
    else:
        weekly_change=0.0

    weight_trend=[]
    for log in weight_logs:
        weight_trend.append({
            "date": log.date.isoformat(),
            "label":log.date.strftime("%b %d"),
            "weight":float(log.weight_kg),
        })
    if not weight_trend:
        weight_trend.append({
            "label": today.strftime("%b %d"),
            "weight":float(current_weight),
        })

    days_labels = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']
    calories_week = []
    for i in range(7):
        day = today - timedelta(days=today.weekday() - i)
        day_history = [h for h in all_history if h.log_date and h.log_date.date() == day]
        day_cals = sum(h.calories or 0 for h in day_history)
        calories_week.append({
            "label": days_labels[i],
            "calories": day_cals,
        })

    return {
        "success": True,
        "start_weight": start_weight,
        "current_weight": current_weight,
        "goal_weight": goal_weight,
        "goal_type": goal_type,
        "changed_so_far": max(changed, 0),
        "remaining": max(remaining, 0),
        "progress_pct": min(max(progress, 0), 100),
        "days_tracking": distinct_days,
        "streak": streak,
        "avg_calories": avg_calories,
        "weekly_change": weekly_change,
        "calorie_goal": calorie_goal,
        "weight_trend": weight_trend,
        "calories_week": calories_week,
    }