from __future__ import annotations

from datetime import datetime
from typing import Any

from pydantic import BaseModel, Field, model_validator


CALCULATOR_PATTERN = "^(text_token_tiered_v1|image_per_output_v1|image_input_output_tiered_v1|video_pixel_token_v1)$"


class ModelPricingRuleBase(BaseModel):
    provider: str = Field(default="volcengine", max_length=32)
    model_name: str = Field(..., min_length=1, max_length=128)
    model_category: str = Field(..., pattern="^(text|image|video)$")
    billing_mode: str = Field(..., pattern="^(text_token_tiered|image_per_output|image_input_output_tiered|video_token_rate)$")
    calculator_version: str = Field(..., pattern=CALCULATOR_PATTERN)
    version_code: str = Field(..., min_length=1, max_length=64)
    effective_from: datetime
    effective_to: datetime | None = None
    currency: str = Field(default="CNY", min_length=3, max_length=8)
    rule_schema_version: int = Field(default=1, ge=1, le=100)
    rule_json: dict[str, Any]
    source_url: str | None = None
    source_updated_at: datetime | None = None
    remark: str | None = None

    @model_validator(mode="after")
    def validate_time_range(self):
        if self.effective_to and self.effective_to <= self.effective_from:
            raise ValueError("effective_to 必须晚于 effective_from")
        return self


class ModelPricingRuleCreate(ModelPricingRuleBase):
    pass


class ModelPricingRuleUpdate(BaseModel):
    provider: str | None = Field(None, max_length=32)
    model_name: str | None = Field(None, min_length=1, max_length=128)
    model_category: str | None = Field(None, pattern="^(text|image|video)$")
    billing_mode: str | None = Field(None, pattern="^(text_token_tiered|image_per_output|image_input_output_tiered|video_token_rate)$")
    calculator_version: str | None = Field(None, pattern=CALCULATOR_PATTERN)
    version_code: str | None = Field(None, min_length=1, max_length=64)
    effective_from: datetime | None = None
    effective_to: datetime | None = None
    currency: str | None = Field(None, min_length=3, max_length=8)
    rule_schema_version: int | None = Field(None, ge=1, le=100)
    rule_json: dict[str, Any] | None = None
    source_url: str | None = None
    source_updated_at: datetime | None = None
    remark: str | None = None


class ModelPricingRuleOut(ModelPricingRuleBase):
    id: str
    publish_status: str
    rule_content_hash: str
    referenced_count: int = 0
    created_by: str | None = None
    updated_by: str | None = None
    created_at: datetime | None = None
    updated_at: datetime | None = None


class ModelPricingRuleListOut(BaseModel):
    items: list[ModelPricingRuleOut]
    total: int


class ModelPricingPreviewRequest(BaseModel):
    billing_mode: str
    calculator_version: str = Field(..., pattern=CALCULATOR_PATTERN)
    rule_json: dict[str, Any]
    usage: dict[str, Any]
    currency: str = "CNY"


class ModelPricingPreviewOut(BaseModel):
    amount: str
    currency: str
    is_estimated: bool
    selected_rate: str | None = None
    usage_source: str
    breakdown: dict[str, Any]