from __future__ import annotations

from datetime import datetime
from typing import Literal, Optional

from pydantic import BaseModel, EmailStr, Field, field_validator

SmtpSecurityValue = Literal["NONE", "SSL", "STARTTLS"]


class EmailSettingsRead(BaseModel):
    register_domain: str = "huapont.cn"
    smtp_host: str = ""
    smtp_port: int = 465
    smtp_security: SmtpSecurityValue = "SSL"
    smtp_username: str = ""
    smtp_password_configured: bool = False
    sender_email: str = ""
    sender_name: Optional[str] = "CTMS 系统"
    allowed_register_domain: str = "huapont.cn,qq.com"
    verification_code_ttl_minutes: int = 10
    send_cooldown_seconds: int = 60
    max_verify_attempts: int = 5
    updated_at: Optional[datetime] = None


class EmailSettingsUpdate(BaseModel):
    smtp_host: str = Field(default="", max_length=255)
    smtp_port: int = Field(ge=1, le=65535)
    smtp_security: SmtpSecurityValue = "SSL"
    smtp_username: str = Field(default="", max_length=255)
    smtp_password: Optional[str] = Field(default=None, max_length=500)
    sender_email: str = Field(default="", max_length=255)
    sender_name: Optional[str] = Field(default="CTMS 系统", max_length=255)
    allowed_register_domain: str = Field(default="", max_length=255)
    verification_code_ttl_minutes: int = Field(default=10, ge=1, le=60)
    send_cooldown_seconds: int = Field(default=60, ge=10, le=3600)
    max_verify_attempts: int = Field(default=5, ge=1, le=20)

    @field_validator("allowed_register_domain")
    @classmethod
    def normalize_domain(cls, value: str) -> str:
        domains = []
        for item in value.replace("，", ",").split(","):
            domain = item.strip().lower().lstrip("@")
            if domain and domain not in domains:
                domains.append(domain)
        if not domains:
            raise ValueError("至少配置一个允许注册邮箱域名")
        return ",".join(domains)


class EmailTestRequest(BaseModel):
    recipient_email: EmailStr


class EmailDomainCreateRequest(BaseModel):
    register_domain: str = Field(min_length=1, max_length=255)

    @field_validator("register_domain")
    @classmethod
    def normalize_domain(cls, value: str) -> str:
        return value.strip().lower().lstrip("@")


class EmailSettingsListResponse(BaseModel):
    items: list[EmailSettingsRead]
    total: int


class RegisterEmailCodeSendRequest(BaseModel):
    email: EmailStr


class RegisterEmailCodeVerifyRequest(BaseModel):
    email: EmailStr
    code: str = Field(min_length=4, max_length=12)


class PasswordResetLinkSendRequest(BaseModel):
    email: EmailStr


class PasswordResetRequest(BaseModel):
    email: EmailStr
    code: str = Field(min_length=4, max_length=12)
    password: str = Field(min_length=8, max_length=72)

    @field_validator("password")
    @classmethod
    def validate_password_strength(cls, value: str) -> str:
        has_letter = any(ch.isalpha() for ch in value)
        has_number = any(ch.isdigit() for ch in value)
        if not has_letter or not has_number:
            raise ValueError("密码需至少 8 位且包含字母和数字")
        return value


class PasswordResetCodeVerifyRequest(BaseModel):
    email: EmailStr
    code: str = Field(min_length=4, max_length=12)


class PasswordResetTokenRequest(BaseModel):
    token: str = Field(min_length=20, max_length=200)
    password: str = Field(min_length=8, max_length=72)

    @field_validator("password")
    @classmethod
    def validate_password_strength(cls, value: str) -> str:
        has_letter = any(ch.isalpha() for ch in value)
        has_number = any(ch.isdigit() for ch in value)
        if not has_letter or not has_number:
            raise ValueError("密码需至少 8 位且包含字母和数字")
        return value


class EmailCodeResponse(BaseModel):
    message: str


class EmailCodeVerifyResponse(BaseModel):
    verified: bool


class PasswordResetCodeVerifyResponse(BaseModel):
    verified: bool
    reset_token: str