# models/schema/vendor.py
"""
Pydantic schemas for Vendor-related operations.

Schemas include:
- VendorCreate: For creating vendors with owner accounts
- VendorUpdate: For updating vendor information (Admin only)
- VendorResponse: Standard vendor response
- VendorDetailResponse: Vendor response with owner details
- VendorCreateResponse: Response after vendor creation (includes credentials)
- VendorListResponse: Paginated vendor list
- VendorSummary: Lightweight vendor info
- VendorTransferOwnership: For transferring vendor ownership
"""

import re
from datetime import datetime
from typing import Any

from pydantic import BaseModel, ConfigDict, Field, field_validator


class VendorCreate(BaseModel):
    """Schema for creating a new vendor with owner account."""

    # Basic Information
    vendor_code: str = Field(
        ...,
        description="Unique vendor identifier (e.g., TECHSTORE)",
        min_length=2,
        max_length=50,
    )
    subdomain: str = Field(
        ..., description="Unique subdomain for the vendor", min_length=2, max_length=100
    )
    name: str = Field(
        ..., description="Display name of the vendor", min_length=2, max_length=255
    )
    description: str | None = Field(None, description="Vendor description")

    # Owner Information (Creates User Account)
    owner_email: str = Field(
        ...,
        description="Email for the vendor owner (used for login and authentication)",
    )

    # Business Contact Information (Vendor Fields)
    contact_email: str | None = Field(
        None,
        description="Public business contact email (defaults to owner_email if not provided)",
    )
    contact_phone: str | None = Field(None, description="Contact phone number")
    website: str | None = Field(None, description="Website URL")

    # Business Details
    business_address: str | None = Field(None, description="Business address")
    tax_number: str | None = Field(None, description="Tax/VAT number")

    # Marketplace URLs (multi-language support)
    letzshop_csv_url_fr: str | None = Field(None, description="French CSV URL")
    letzshop_csv_url_en: str | None = Field(None, description="English CSV URL")
    letzshop_csv_url_de: str | None = Field(None, description="German CSV URL")

    @field_validator("owner_email", "contact_email")
    @classmethod
    def validate_emails(cls, v):
        """Validate email format and normalize to lowercase."""
        if v and ("@" not in v or "." not in v):
            raise ValueError("Invalid email format")
        return v.lower() if v else v

    @field_validator("subdomain")
    @classmethod
    def validate_subdomain(cls, v):
        """Validate subdomain format: lowercase alphanumeric with hyphens."""
        if v and not re.match(r"^[a-z0-9][a-z0-9-]*[a-z0-9]$", v):
            raise ValueError(
                "Subdomain must contain only lowercase letters, numbers, and hyphens"
            )
        return v.lower() if v else v

    @field_validator("vendor_code")
    @classmethod
    def validate_vendor_code(cls, v):
        """Ensure vendor code is uppercase for consistency."""
        return v.upper() if v else v


class VendorUpdate(BaseModel):
    """
    Schema for updating vendor information (Admin only).

    Note: owner_email is NOT included here. To change the owner,
    use the transfer-ownership endpoint instead.
    """

    # Basic Information
    name: str | None = Field(None, min_length=2, max_length=255)
    description: str | None = None
    subdomain: str | None = Field(None, min_length=2, max_length=100)

    # Business Contact Information (Vendor Fields)
    contact_email: str | None = Field(
        None, description="Public business contact email"
    )
    contact_phone: str | None = None
    website: str | None = None

    # Business Details
    business_address: str | None = None
    tax_number: str | None = None

    # Marketplace URLs
    letzshop_csv_url_fr: str | None = None
    letzshop_csv_url_en: str | None = None
    letzshop_csv_url_de: str | None = None

    # Status (Admin only)
    is_active: bool | None = None
    is_verified: bool | None = None

    @field_validator("subdomain")
    @classmethod
    def subdomain_lowercase(cls, v):
        """Normalize subdomain to lowercase."""
        return v.lower().strip() if v else v

    @field_validator("contact_email")
    @classmethod
    def validate_contact_email(cls, v):
        """Validate contact email format."""
        if v and ("@" not in v or "." not in v):
            raise ValueError("Invalid email format")
        return v.lower() if v else v

    model_config = ConfigDict(from_attributes=True)


class VendorResponse(BaseModel):
    """Standard schema for vendor response data."""

    model_config = ConfigDict(from_attributes=True)

    id: int
    vendor_code: str
    subdomain: str
    name: str
    description: str | None
    owner_user_id: int

    # Contact Information (Business)
    contact_email: str | None
    contact_phone: str | None
    website: str | None

    # Business Information
    business_address: str | None
    tax_number: str | None

    # Marketplace URLs
    letzshop_csv_url_fr: str | None
    letzshop_csv_url_en: str | None
    letzshop_csv_url_de: str | None

    # Status Flags
    is_active: bool
    is_verified: bool

    # Timestamps
    created_at: datetime
    updated_at: datetime


class VendorDetailResponse(VendorResponse):
    """
    Extended vendor response including owner information.

    Includes both:
    - contact_email (business contact)
    - owner_email (owner's authentication email)
    """

    owner_email: str = Field(
        ..., description="Email of the vendor owner (for login/authentication)"
    )
    owner_username: str = Field(..., description="Username of the vendor owner")


class VendorCreateResponse(VendorDetailResponse):
    """
    Response after creating vendor - includes generated credentials.

    IMPORTANT: temporary_password is shown only once!
    """

    temporary_password: str = Field(
        ..., description="Temporary password for owner (SHOWN ONLY ONCE)"
    )
    login_url: str | None = Field(None, description="URL for vendor owner to login")


class VendorListResponse(BaseModel):
    """Schema for paginated vendor list."""

    vendors: list[VendorResponse]
    total: int
    skip: int
    limit: int


class VendorSummary(BaseModel):
    """Lightweight vendor summary for dropdowns and quick references."""

    model_config = ConfigDict(from_attributes=True)

    id: int
    vendor_code: str
    subdomain: str
    name: str
    is_active: bool


class VendorTransferOwnership(BaseModel):
    """
    Schema for transferring vendor ownership to another user.

    This is a critical operation that requires:
    - Confirmation flag
    - Reason for audit trail (optional)
    """

    new_owner_user_id: int = Field(
        ..., description="ID of the user who will become the new owner", gt=0
    )

    confirm_transfer: bool = Field(
        ..., description="Must be true to confirm ownership transfer"
    )

    transfer_reason: str | None = Field(
        None,
        max_length=500,
        description="Reason for ownership transfer (for audit logs)",
    )

    @field_validator("confirm_transfer")
    @classmethod
    def validate_confirmation(cls, v):
        """Ensure confirmation is explicitly true."""
        if not v:
            raise ValueError("Ownership transfer requires explicit confirmation")
        return v


class VendorTransferOwnershipResponse(BaseModel):
    """Response after successful ownership transfer."""

    message: str
    vendor_id: int
    vendor_code: str
    vendor_name: str

    old_owner: dict[str, Any] = Field(
        ..., description="Information about the previous owner"
    )
    new_owner: dict[str, Any] = Field(
        ..., description="Information about the new owner"
    )

    transferred_at: datetime
    transfer_reason: str | None