"""
兑换码相关 Schema

定义兑换码数据的验证和序列化规则。
"""

from datetime import datetime
from typing import Annotated

from pydantic import Field, field_validator

from app.schemas.base import BaseSchema, PaginatedResponse
from app.schemas.balance import UNITS_PER_DISPLAY, display_to_units, format_display
from app.models.redeem_code import RedeemCodeStatus


# ============================================================
# 用户兑换 Schema
# ============================================================

class RedeemRequest(BaseSchema):
    """兑换请求"""
    
    code: Annotated[
        str,
        Field(
            min_length=1,
            max_length=32,
            description="兑换码",
            examples=["ABCD-EFGH-JKLM-NPQR"],
        ),
    ]
    
    @field_validator("code")
    @classmethod
    def normalize_code(cls, v: str) -> str:
        """标准化兑换码格式"""
        # 移除空格，转大写
        return v.strip().upper().replace(" ", "")


class RedeemResponse(BaseSchema):
    """兑换响应"""
    
    success: bool = True
    message: str = "兑换成功"
    face_value: str = Field(description="兑换金额")
    balance_before: str = Field(description="兑换前余额")
    balance_after: str = Field(description="兑换后余额")


# ============================================================
# 兑换码信息 Schema
# ============================================================

class RedeemCodeResponse(BaseSchema):
    """兑换码信息响应"""
    
    id: str
    code: str
    face_value_units: int = Field(description="面值（单位额度）")
    status: RedeemCodeStatus
    max_uses: int
    used_count: int
    expires_at: datetime | None
    used_at: datetime | None
    created_at: datetime
    
    @property
    def face_value(self) -> str:
        """显示面值（2 位小数）"""
        return format_display(self.face_value_units)
    
    @property
    def is_valid(self) -> bool:
        """是否有效"""
        if self.status != RedeemCodeStatus.ACTIVE:
            return False
        if self.used_count >= self.max_uses:
            return False
        if self.expires_at and self.expires_at < datetime.now(self.expires_at.tzinfo):
            return False
        return True


class RedeemCodeDetailResponse(RedeemCodeResponse):
    """兑换码详细信息响应（管理员用）"""
    
    batch_id: str | None
    batch_name: str | None = None
    remark: str | None
    created_by: str | None
    used_by: str | None


class RedeemCodeListResponse(PaginatedResponse[RedeemCodeDetailResponse]):
    """兑换码列表响应"""
    pass


# ============================================================
# 批次 Schema
# ============================================================

class BatchCreateRequest(BaseSchema):
    """创建兑换码批次请求"""
    
    name: Annotated[
        str,
        Field(
            min_length=1,
            max_length=128,
            description="批次名称",
            examples=["2024年1月活动"],
        ),
    ]
    description: Annotated[
        str | None,
        Field(
            default=None,
            max_length=500,
            description="批次描述",
        ),
    ]
    face_value: Annotated[
        float,
        Field(
            gt=0,
            description="面值（显示金额）",
            examples=[10.00, 50.00],
        ),
    ]
    count: Annotated[
        int,
        Field(
            gt=0,
            le=10000,
            description="生成数量",
            examples=[100],
        ),
    ]
    max_uses: Annotated[
        int,
        Field(
            default=1,
            gt=0,
            le=100,
            description="每个兑换码最大使用次数",
        ),
    ]
    expires_at: Annotated[
        datetime | None,
        Field(
            default=None,
            description="过期时间",
        ),
    ]
    
    @field_validator("face_value")
    @classmethod
    def validate_face_value(cls, v: float) -> float:
        """验证面值精度"""
        if round(v, 3) != v:
            raise ValueError("面值精度不能超过 3 位小数")
        return v
    
    @property
    def face_value_units(self) -> int:
        """转换为单位额度"""
        return display_to_units(self.face_value)


class BatchResponse(BaseSchema):
    """批次信息响应"""
    
    id: str
    name: str
    description: str | None
    face_value_units: int
    total_count: int
    used_count: int
    created_by: str | None
    created_at: datetime
    
    @property
    def face_value(self) -> str:
        """显示面值（2 位小数）"""
        return format_display(self.face_value_units)
    
    @property
    def unused_count(self) -> int:
        """未使用数量"""
        return self.total_count - self.used_count


class BatchDetailResponse(BatchResponse):
    """批次详细信息响应"""
    
    codes: list[RedeemCodeResponse] = []


class BatchListResponse(PaginatedResponse[BatchResponse]):
    """批次列表响应"""
    pass


# ============================================================
# 导入导出 Schema
# ============================================================

class ImportCodeRequest(BaseSchema):
    """导入兑换码请求"""
    
    code: Annotated[
        str,
        Field(
            min_length=1,
            max_length=32,
            description="兑换码",
        ),
    ]
    face_value: Annotated[
        float,
        Field(
            gt=0,
            description="面值",
        ),
    ]
    max_uses: Annotated[
        int,
        Field(
            default=1,
            gt=0,
        ),
    ]
    expires_at: datetime | None = None
    remark: str | None = None
    
    @field_validator("code")
    @classmethod
    def normalize_code(cls, v: str) -> str:
        """标准化兑换码"""
        return v.strip().upper()
    
    @property
    def face_value_units(self) -> int:
        """转换为单位额度"""
        return display_to_units(self.face_value)


class BulkImportRequest(BaseSchema):
    """批量导入兑换码请求"""
    
    codes: Annotated[
        list[ImportCodeRequest],
        Field(
            min_length=1,
            max_length=1000,
            description="兑换码列表",
        ),
    ]
    batch_name: Annotated[
        str | None,
        Field(
            default=None,
            max_length=128,
            description="批次名称（可选）",
        ),
    ]


class BulkImportResponse(BaseSchema):
    """批量导入响应"""
    
    success_count: int
    failed_count: int
    failed_codes: list[str] = []
    batch_id: str | None = None


class ExportCodeItem(BaseSchema):
    """导出兑换码条目"""
    
    code: str
    face_value: str
    status: str
    max_uses: int
    used_count: int
    expires_at: str | None
    created_at: str
    used_at: str | None
    used_by: str | None


class ExportResponse(BaseSchema):
    """导出响应"""
    
    total: int
    codes: list[ExportCodeItem]


# ============================================================
# 使用日志 Schema
# ============================================================

class UsageLogResponse(BaseSchema):
    """兑换码使用日志响应"""
    
    id: str
    redeem_code_id: str
    code_snapshot: str
    user_id: str
    username: str | None = None
    face_value: str
    ip_address: str | None
    created_at: datetime


class UsageLogListResponse(PaginatedResponse[UsageLogResponse]):
    """使用日志列表响应"""
    pass


# ============================================================
# 查询参数 Schema
# ============================================================

class RedeemCodeQueryParams(BaseSchema):
    """兑换码查询参数"""
    
    status: RedeemCodeStatus | None = None
    batch_id: str | None = None
    code: str | None = None
    created_after: datetime | None = None
    created_before: datetime | None = None


class UsageLogQueryParams(BaseSchema):
    """使用日志查询参数"""
    
    redeem_code_id: str | None = None
    user_id: str | None = None
    code: str | None = None
    created_after: datetime | None = None
    created_before: datetime | None = None