from datetime import datetime, date
from enum import Enum
from typing import List, Optional, Dict, Any
from uuid import UUID, uuid4
from sqlmodel import Field, SQLModel, Relationship, JSON

# --- ENUMS ---
class ClassEnum(str, Enum):
    ELEVENTH = "11"
    TWELFTH = "12"
    DROPPER = "Dropper"

class ExamEnum(str, Enum):
    JEE_MAIN = "JEE_Main"
    JEE_ADVANCED = "JEE_Advanced"
    NEET = "NEET"

class MediumEnum(str, Enum):
    ENGLISH = "English"
    HINDI = "Hindi"
    BILINGUAL = "Bilingual"

class TierEnum(str, Enum):
    FREE = "Free"
    PRO = "Pro"
    AI_COACH = "Al_Coach"

class QuestionTypeEnum(str, Enum):
    MCQ_SINGLE = "MCQ_Single"
    MCQ_MULTIPLE = "MCQ_Multiple"
    NUMERICAL = "Numerical"

class SourceTypeEnum(str, Enum):
    DPS = "DPS"
    TEST = "Test"
    MICROTEST = "MicroTest"

class ErrorTypeEnum(str, Enum):
    CONCEPTUAL = "Conceptual"
    CALCULATION = "Calculation"
    READING = "Reading"
    TIME_PRESSURE = "Time_Pressure"

# --- CORE DB MODELS ---

class User(SQLModel, table=True):
    id: UUID = Field(default_factory=uuid4, primary_key=True)
    email: Optional[str] = Field(default=None, unique=True)
    phone: Optional[str] = Field(default=None, unique=True)
    password_hash: str
    name: str
    student_class: ClassEnum = Field(alias="class")
    target_exam: ExamEnum
    medium: MediumEnum
    school: Optional[str] = None
    city: str
    state: str
    tier: TierEnum = Field(default=TierEnum.FREE)
    trial_end: Optional[datetime] = None
    subscription_end: Optional[datetime] = None
    streak_count: int = Field(default=0)
    longest_streak: int = Field(default=0)
    created_at: datetime = Field(default_factory=datetime.utcnow)
    last_active: datetime = Field(default_factory=datetime.utcnow)

class Parent(SQLModel, table=True):
    id: UUID = Field(default_factory=uuid4, primary_key=True)
    email: str
    phone: str
    password_hash: str
    name: str
    language: str = Field(default="English")  # e.g., Hindi, English
    linked_students: List[str] = Field(default=[], sa_type=JSON) 
    created_at: datetime = Field(default_factory=datetime.utcnow)

class Question(SQLModel, table=True):
    id: UUID = Field(default_factory=uuid4, primary_key=True)
    subject: str  # Physics, Chemistry, Maths, Biology
    topic: str
    subtopic: str
    difficulty: str  # Easy, Medium, Hard
    type: QuestionTypeEnum
    question_text: str
    question_text_hi: Optional[str] = None
    options: Optional[Dict[str, Any]] = Field(default=None, sa_type=JSON)
    options_hi: Optional[Dict[str, Any]] = Field(default=None, sa_type=JSON)
    correct_answer: Dict[str, Any] = Field(sa_type=JSON)
    solution_text: str
    solution_text_hi: Optional[str] = None
    language: MediumEnum
    year: Optional[int] = None
    exam: Optional[ExamEnum] = None
    tags: Optional[str] = None
    is_active: bool = Field(default=True)
    created_by: UUID
    verified_by: Optional[UUID] = None

class DPS(SQLModel, table=True):
    id: UUID = Field(default_factory=uuid4, primary_key=True)
    date: date
    title: str
    questions: List[str] = Field(default=[], sa_type=JSON)  # Array of question UUID strings
    difficulty: str
    time_limit: int
    is_active: bool = Field(default=True)
    created_by: UUID

class Test(SQLModel, table=True):
    id: UUID = Field(default_factory=uuid4, primary_key=True)
    title: str
    type: str  # Weekly, Mock, PYQ
    exam_pattern: ExamEnum
    sections: Dict[str, Any] = Field(sa_type=JSON)  # Array of {name, questions[], time_limit}
    total_time: int
    difficulty: str
    scheduled_date: Optional[datetime] = None
    end_date: Optional[datetime] = None
    is_active: bool = Field(default=True)
    created_by: UUID

class Attempt(SQLModel, table=True):
    id: UUID = Field(default_factory=uuid4, primary_key=True)
    user_id: UUID = Field(foreign_key="user.id")
    source_type: SourceTypeEnum
    source_id: UUID
    started_at: datetime
    submitted_at: Optional[datetime] = None
    time_taken: Optional[int] = None  # in seconds
    answers: Optional[Dict[str, Any]] = Field(default=None, sa_type=JSON)  # Array of {question_id, selected_answer, is_correct, time_spent}
    score: int = Field(default=0)
    total_questions: int
    accuracy: float = Field(default=0.0)
    status: str = Field(default="In_Progress")  # In_Progress, Submitted, Timed_Out

class Mistake(SQLModel, table=True):
    id: UUID = Field(default_factory=uuid4, primary_key=True)
    user_id: UUID = Field(foreign_key="user.id")
    question_id: UUID = Field(foreign_key="question.id")
    attempt_id: UUID = Field(foreign_key="attempt.id")
    error_type: ErrorTypeEnum
    topic: str
    subtopic: str
    next_review: datetime
    review_count: int = Field(default=0)
    consecutive_correct: int = Field(default=0)
    is_mastered: bool = Field(default=False)
    created_at: datetime = Field(default_factory=datetime.utcnow)

class StudyPlan(SQLModel, table=True):
    id: UUID = Field(default_factory=uuid4, primary_key=True)
    user_id: UUID = Field(foreign_key="user.id")
    date: date
    tasks: Dict[str, Any] = Field(sa_type=JSON)  # Array of {type, description, duration_minutes, status}
    is_completed: bool = Field(default=False)
    generated_at: datetime = Field(default_factory=datetime.utcnow)
    feedback: Optional[str] = None

class Subscription(SQLModel, table=True):
    id: UUID = Field(default_factory=uuid4, primary_key=True)
    user_id: UUID = Field(foreign_key="user.id")
    tier: TierEnum
    billing_cycle: str  # Monthly, Quarterly, Annual
    start_date: datetime
    end_date: datetime
    amount: int  # Stored in Paise (INR)
    payment_id: str  # Razorpay order ID / payment ID
    status: str  # Active, Expired, Cancelled, Paused
    auto_renew: bool = Field(default=True)
    coupon_code: Optional[str] = None