import datetime
import json
from sqlalchemy import Column, Integer, String, Boolean, DateTime, Date, ForeignKey, Float, Text, Time, Interval, Enum
from sqlalchemy.types import TypeDecorator
from sqlalchemy.orm import relationship
from app.core.database import Base

class SafeVector(TypeDecorator):
    impl = Text
    cache_ok = True

    def __init__(self, dimensions):
        self.dimensions = dimensions
        super().__init__()

    def load_dialect_impl(self, dialect):
        if dialect.name == 'postgresql':
            try:
                from pgvector.sqlalchemy import Vector
                return dialect.type_descriptor(Vector(self.dimensions))
            except ImportError:
                pass
        return dialect.type_descriptor(Text())

    def process_bind_param(self, value, dialect):
        if value is None:
            return None
        if dialect.name == 'postgresql':
            return value
        return json.dumps(value)

    def process_result_value(self, value, dialect):
        if value is None:
            return None
        if dialect.name == 'postgresql':
            return value
        try:
            return json.loads(value)
        except Exception:
            return value

class Role(Base):
    __tablename__ = "roles"

    id = Column(Integer, primary_key=True, index=True)
    name = Column(String(50), unique=True, nullable=False)  # Super Admin, Admin, HR, Employee
    description = Column(String(255), nullable=True)

    users = relationship("User", back_populates="role")

class User(Base):
    __tablename__ = "users"

    id = Column(Integer, primary_key=True, index=True)
    email = Column(String(255), unique=True, index=True, nullable=False)
    hashed_password = Column(String(255), nullable=False)
    is_active = Column(Boolean, default=True)
    role_id = Column(Integer, ForeignKey("roles.id"), nullable=False)
    created_at = Column(DateTime, default=datetime.datetime.utcnow)
    updated_at = Column(DateTime, default=datetime.datetime.utcnow, onupdate=datetime.datetime.utcnow)

    role = relationship("Role", back_populates="users")
    employee = relationship("Employee", back_populates="user", uselist=False)
    audit_logs = relationship("AuditLog", back_populates="user")

class Department(Base):
    __tablename__ = "departments"

    id = Column(Integer, primary_key=True, index=True)
    name = Column(String(100), unique=True, nullable=False)
    code = Column(String(20), unique=True, nullable=False)
    description = Column(String(255), nullable=True)

    employees = relationship("Employee", back_populates="department")

class Employee(Base):
    __tablename__ = "employees"

    id = Column(Integer, primary_key=True, index=True)
    employee_id = Column(String(50), unique=True, index=True, nullable=False)
    name = Column(String(100), nullable=False)
    email = Column(String(255), unique=True, index=True, nullable=False)
    phone = Column(String(20), nullable=True)
    designation = Column(String(100), nullable=True)
    joining_date = Column(Date, nullable=False, default=datetime.date.today)
    status = Column(String(20), default="Active")  # Active, Inactive, Suspended
    department_id = Column(Integer, ForeignKey("departments.id"), nullable=True)
    user_id = Column(Integer, ForeignKey("users.id"), nullable=True, unique=True)
    created_at = Column(DateTime, default=datetime.datetime.utcnow)
    updated_at = Column(DateTime, default=datetime.datetime.utcnow, onupdate=datetime.datetime.utcnow)

    department = relationship("Department", back_populates="employees")
    user = relationship("User", back_populates="employee")
    images = relationship("EmployeeImage", back_populates="employee", cascade="all, delete-orphan")
    embeddings = relationship("FaceEmbedding", back_populates="employee", cascade="all, delete-orphan")
    attendance_records = relationship("Attendance", back_populates="employee", cascade="all, delete-orphan")
    attendance_logs = relationship("AttendanceLog", back_populates="employee", cascade="all, delete-orphan")
    leave_requests = relationship("LeaveRequest", back_populates="employee", cascade="all, delete-orphan")

class EmployeeImage(Base):
    __tablename__ = "employee_images"

    id = Column(Integer, primary_key=True, index=True)
    employee_id = Column(Integer, ForeignKey("employees.id", ondelete="CASCADE"), nullable=False)
    file_path = Column(String(255), nullable=False)
    pose_type = Column(String(50), nullable=False)  # Front, Left, Right, Up, Down, Smile, Neutral, etc.
    created_at = Column(DateTime, default=datetime.datetime.utcnow)

    employee = relationship("Employee", back_populates="images")
    embeddings = relationship("FaceEmbedding", back_populates="image", cascade="all, delete-orphan")

class FaceEmbedding(Base):
    __tablename__ = "face_embeddings"

    id = Column(Integer, primary_key=True, index=True)
    employee_id = Column(Integer, ForeignKey("employees.id", ondelete="CASCADE"), nullable=False)
    image_id = Column(Integer, ForeignKey("employee_images.id", ondelete="CASCADE"), nullable=True)
    embedding = Column(SafeVector(512), nullable=False)  # pgvector field for 512 dimensions (ArcFace) or JSON text on SQLite
    created_at = Column(DateTime, default=datetime.datetime.utcnow)

    employee = relationship("Employee", back_populates="embeddings")
    image = relationship("EmployeeImage", back_populates="embeddings")

class Attendance(Base):
    __tablename__ = "attendance"

    id = Column(Integer, primary_key=True, index=True)
    employee_id = Column(Integer, ForeignKey("employees.id", ondelete="CASCADE"), nullable=False)
    date = Column(Date, nullable=False)
    check_in = Column(DateTime, nullable=True)
    check_out = Column(DateTime, nullable=True)
    working_hours = Column(Float, default=0.0)  # Calculated in hours
    late_arrival = Column(Boolean, default=False)
    early_departure = Column(Boolean, default=False)
    overtime = Column(Float, default=0.0)  # Calculated in hours
    status = Column(String(20), default="Absent")  # Present, Absent, Late, Half Day, Leave, Holiday, WFH

    employee = relationship("Employee", back_populates="attendance_records")

class AttendanceLog(Base):
    __tablename__ = "attendance_logs"

    id = Column(Integer, primary_key=True, index=True)
    employee_id = Column(Integer, ForeignKey("employees.id", ondelete="CASCADE"), nullable=True)  # Null if not recognized
    timestamp = Column(DateTime, default=datetime.datetime.now, nullable=False)
    camera = Column(String(100), default="Kiosk")
    confidence = Column(Float, nullable=True)
    liveness_score = Column(Float, nullable=True)
    is_spoof = Column(Boolean, default=False)
    status = Column(String(50), nullable=False)  # Match Success, Spoof Rejected, Unknown Person, Low Confidence

    employee = relationship("Employee", back_populates="attendance_logs")

class LeaveRequest(Base):
    __tablename__ = "leave_requests"

    id = Column(Integer, primary_key=True, index=True)
    employee_id = Column(Integer, ForeignKey("employees.id", ondelete="CASCADE"), nullable=False)
    start_date = Column(Date, nullable=False)
    end_date = Column(Date, nullable=False)
    leave_type = Column(String(50), nullable=False)  # Sick, Casual, Annual, unpaid
    reason = Column(Text, nullable=True)
    status = Column(String(20), default="Pending")  # Pending, Approved, Rejected
    approved_by = Column(Integer, ForeignKey("users.id"), nullable=True)
    created_at = Column(DateTime, default=datetime.datetime.utcnow)

    employee = relationship("Employee", back_populates="leave_requests")

class Holiday(Base):
    __tablename__ = "holidays"

    id = Column(Integer, primary_key=True, index=True)
    name = Column(String(100), nullable=False)
    date = Column(Date, unique=True, nullable=False)
    description = Column(String(255), nullable=True)

class Setting(Base):
    __tablename__ = "settings"

    id = Column(Integer, primary_key=True, index=True)
    key = Column(String(100), unique=True, nullable=False)
    value = Column(Text, nullable=False)
    description = Column(String(255), nullable=True)

class AuditLog(Base):
    __tablename__ = "audit_logs"

    id = Column(Integer, primary_key=True, index=True)
    user_id = Column(Integer, ForeignKey("users.id", ondelete="SET NULL"), nullable=True)
    action = Column(String(100), nullable=False)  # Login, Logout, Create Employee, Mark Attendance, etc.
    timestamp = Column(DateTime, default=datetime.datetime.now)
    ip_address = Column(String(50), nullable=True)
    user_agent = Column(String(255), nullable=True)
    details = Column(Text, nullable=True)

    user = relationship("User", back_populates="audit_logs")