"""Validated public API contracts. Platform state is intentionally not a closed enum."""

import re
from datetime import date, datetime, timezone
from typing import Literal
from zoneinfo import ZoneInfo, ZoneInfoNotFoundError

from pydantic import BaseModel, ConfigDict, Field, field_validator, model_validator

ResearchState = Literal["inbox", "candidate", "optimizing", "archived"]
Submission = Literal["UNSUBMITTED", "SUBMITTED"]
CheckType = Literal["PENDING", "PRE_CHECK", "PASS", "FAIL_1", "FAIL_2"]
SortField = Literal[
    "id",
    "name",
    "sharpe",
    "fitness",
    "returns",
    "turnover",
    "margin",
    "drawdown",
    "sub_universe_sharpe",
    "robust_universe_sharpe",
    "two_year_sharpe",
    "prod_correlation",
    "pnl",
    "date_created",
    "date_submitted",
    "synced_at",
]


class Contract(BaseModel):
    model_config = ConfigDict(extra="forbid", allow_inf_nan=False)


class LoginInput(Contract):
    username: str = Field(min_length=1, max_length=100)
    password: str = Field(min_length=1, max_length=1024)


class CredentialsInput(Contract):
    email: str = Field(max_length=254)
    password: str = Field(min_length=1, max_length=1024)

    @field_validator("email")
    @classmethod
    def valid_email(cls, value):
        value = value.strip()
        if not re.fullmatch(r"[^\s@]+@[^\s@]+\.[^\s@]+", value):
            raise ValueError("邮箱格式不正确")
        return value


class PreferencesInput(Contract):
    display_name: str = Field(min_length=1, max_length=100)
    theme: Literal["light", "dark"]
    timezone: str
    page_size: Literal[25, 50, 100]

    @field_validator("timezone")
    @classmethod
    def valid_timezone(cls, value):
        try:
            ZoneInfo(value)
        except (ZoneInfoNotFoundError, ValueError):
            raise ValueError("未知时区") from None
        return value


class AlphaFilters(Contract):
    submission: Submission | None = None
    source: str | None = Field(default=None, max_length=100)
    source_reference: str | None = Field(default=None, max_length=200)
    research_id: str | None = Field(default=None, max_length=200)
    backtest_run_id: str | None = Field(default=None, max_length=36)
    q: str | None = Field(default=None, max_length=300)
    region: str | None = None
    universe: str | None = None
    alpha_type: str | None = None
    language: str | None = None
    status: str | None = None
    stage: str | None = None
    hidden: bool | None = None
    check_type: CheckType | None = None
    neutralization: str | None = None
    research_state: ResearchState | None = None
    favorite: bool | None = None
    tag: str | None = Field(default=None, max_length=60)
    created_from: datetime | None = None
    created_to: datetime | None = None
    sharpe_min: float | None = None
    sharpe_max: float | None = None
    fitness_min: float | None = None
    fitness_max: float | None = None
    returns_min: float | None = None
    returns_max: float | None = None
    turnover_min: float | None = None
    turnover_max: float | None = None
    margin_min: float | None = None
    margin_max: float | None = None
    drawdown_min: float | None = None
    drawdown_max: float | None = None
    sub_universe_sharpe_min: float | None = None
    sub_universe_sharpe_max: float | None = None
    robust_universe_sharpe_min: float | None = None
    robust_universe_sharpe_max: float | None = None
    two_year_sharpe_min: float | None = None
    two_year_sharpe_max: float | None = None
    prod_correlation_min: float | None = None
    prod_correlation_max: float | None = None
    pnl_min: float | None = None
    pnl_max: float | None = None
    sort: SortField = "date_created"
    direction: Literal["asc", "desc"] = "desc"
    limit: int = Field(default=25, ge=1, le=100)
    offset: int = Field(default=0, ge=0)

    @field_validator("created_from", "created_to")
    @classmethod
    def utc_dates(cls, value):
        return value.replace(tzinfo=timezone.utc) if value and value.tzinfo is None else value

    @model_validator(mode="after")
    def range_order(self):
        for key in (
            "sharpe", "fitness", "returns", "turnover", "margin", "drawdown",
            "sub_universe_sharpe", "robust_universe_sharpe", "two_year_sharpe", "prod_correlation", "pnl",
        ):
            lo, hi = getattr(self, f"{key}_min"), getattr(self, f"{key}_max")
            if lo is not None and hi is not None and lo > hi:
                raise ValueError(f"{key} 最小值不能大于最大值")
        if self.created_from and self.created_to and self.created_from > self.created_to:
            raise ValueError("开始时间不能晚于结束时间")
        return self


def normalize_tags(values):
    result = sorted(set(v.strip() for v in values if v.strip()))
    if len(result) > 30 or any(len(v) > 60 for v in result):
        raise ValueError("最多 30 个标签，每个标签最多 60 字符")
    return result


class ResearchInput(Contract):
    note: str = Field(default="", max_length=20000)
    tags: list[str] = Field(default_factory=list)
    favorite: bool = False
    state: ResearchState = "inbox"
    _tags = field_validator("tags")(normalize_tags)


class ResearchUpdate(ResearchInput):
    version: int = Field(ge=1)


def valid_ids(values):
    result = list(dict.fromkeys(values))
    if not result or len(result) > 100 or any(not re.fullmatch(r"[A-Za-z0-9_-]{1,100}", v) for v in result):
        raise ValueError("请输入 1–100 个合法 Alpha ID（字母、数字、下划线或短横线）")
    return result


class BulkInput(Contract):
    alpha_ids: list[str]
    add_tags: list[str] = Field(default_factory=list)
    remove_tags: list[str] = Field(default_factory=list)
    state: ResearchState | None = None
    _ids = field_validator("alpha_ids")(valid_ids)
    _tags = field_validator("add_tags", "remove_tags")(normalize_tags)

    @model_validator(mode="after")
    def disjoint(self):
        if set(self.add_tags) & set(self.remove_tags):
            raise ValueError("同一标签不能同时添加和移除")
        return self


class BulkUpdate(BulkInput):
    versions: dict[str, int]

    @model_validator(mode="after")
    def check_versions(self):
        if set(self.versions) != set(self.alpha_ids) or any(v < 1 for v in self.versions.values()):
            raise ValueError("每个目标 Alpha 都必须提供当前版本")
        return self


class JobInput(Contract):
    kind: Literal["full_sync", "daily_sync", "alpha_refresh", "pnl_refresh", "self_correlation"]
    alpha_ids: list[str] = Field(default_factory=list)
    submission: Submission | None = None
    date_from: date | None = None
    date_to: date | None = None

    @model_validator(mode="after")
    def validate_ids(self):
        if self.kind in ("full_sync", "daily_sync"):
            if self.alpha_ids:
                raise ValueError("列表同步不接受 Alpha ID")
            if self.kind == "full_sync":
                if self.submission == "UNSUBMITTED":
                    raise ValueError("待提交 Alpha 必须选择日期逐天同步")
                self.submission = "SUBMITTED"
                if self.date_from is not None or self.date_to is not None:
                    raise ValueError("全量同步不接受日期范围")
            else:
                if not self.submission or not self.date_from or not self.date_to:
                    raise ValueError("按天同步必须选择待提交/已提交和起止日期")
                if self.date_from > self.date_to:
                    raise ValueError("开始日期不能晚于结束日期")
                if self.date_to > datetime.now(timezone.utc).date():
                    raise ValueError("同步日期不能晚于今天（UTC）")
        else:
            self.alpha_ids = valid_ids(self.alpha_ids)
            if self.submission is not None or self.date_from is not None or self.date_to is not None:
                raise ValueError("按 ID 操作不接受分组或日期范围")
        return self


class ResearchOutput(ResearchInput):
    updated_at: datetime
    version: int


class AlphaSummary(BaseModel):
    id: str
    name: str | None
    expression_preview: str
    alpha_type: str | None
    language: str | None
    stage: str | None
    status: str | None
    hidden: bool
    region: str | None
    universe: str | None
    sharpe: float | None
    fitness: float | None
    returns: float | None
    turnover: float | None
    margin: float | None
    drawdown: float | None
    date_created: datetime | None
    date_submitted: datetime | None
    synced_at: datetime
    check_type: CheckType = "PENDING"
    failed_checks: list[str] = Field(default_factory=list)
    neutralization: str | None = None
    sub_universe_sharpe: float | None = None
    robust_universe_sharpe: float | None = None
    two_year_sharpe: float | None = None
    prod_correlation: float | None = None
    pnl: float | None = None
    research: ResearchOutput
    local_correlation: dict | None = None
    source_kinds: list[str] = Field(default_factory=list)


class AlphaSourceOutput(BaseModel):
    backtest_run_id: str
    name: str
    source: dict
    item_id: str
    client_item_id: str
    observed_at: datetime


class AlphaSourcePage(BaseModel):
    alpha_id: str
    items: list[AlphaSourceOutput]
    total: int
    limit: int
    offset: int


class AlphaDetail(AlphaSummary):
    expression: str | None
    selection: str | None
    combo: str | None
    settings: dict
    is_metrics: dict
    os_metrics: dict
    checks: list


class AlphaPage(BaseModel):
    items: list[AlphaSummary]
    total: int
    limit: int
    offset: int


class JobOutput(BaseModel):
    model_config = ConfigDict(from_attributes=True)
    id: str
    kind: str
    status: str
    payload: dict = Field(default_factory=dict)
    processed: int
    failed: int
    total: int | None
    error: str | None
    next_retry_at: datetime | None
    created_at: datetime
    updated_at: datetime
    checkpoint: dict = Field(default_factory=dict)


class PlatformSessionOutput(BaseModel):
    authenticated: bool
    expires_at: datetime | None
    remaining_seconds: int | None
    total_seconds: float | None


class AccountOutput(BaseModel):
    email: str | None
    configured: bool
    credentials_source: Literal["environment", "database"]
    wq_user_id: str | None
    profile: dict
    connection_status: str
    connection_error: str | None
    verification_url: str | None
    last_synced_at: datetime | None
    display_name: str
    theme: Literal["light", "dark"]
    timezone: str
    page_size: int
    session: PlatformSessionOutput


class SessionOutput(BaseModel):
    username: str


class OkOutput(BaseModel):
    ok: bool


class ErrorOutput(BaseModel):
    detail: str


class HealthOutput(BaseModel):
    status: Literal["ok"]


class BulkOutput(BaseModel):
    updated: int


class PnlPoint(BaseModel):
    date: str
    value: float | None


class PnlOutput(BaseModel):
    cached: bool
    points: list[PnlPoint]
    fetched_at: datetime | None


class SelfCorrelationOutput(BaseModel):
    cached: bool
    result: dict | None


class FacetsOutput(BaseModel):
    region: list[str]
    universe: list[str]
    alpha_type: list[str]
    language: list[str]
    status: list[str]
    stage: list[str]
    tags: list[str]
    total: int
    favorites: int
    last_sync: datetime | None
    source: list[str] = Field(default_factory=list)


class JobErrorOutput(BaseModel):
    alpha_id: str
    error: str