"""6 张表 ORM: leagues / teams / matches / match_stats / predictions / injuries。"""
from __future__ import annotations

from datetime import date, datetime, timezone

from sqlalchemy import (
    Boolean,
    CheckConstraint,
    Date,
    DateTime,
    Float,
    ForeignKey,
    Index,
    Integer,
    String,
    Text,
    func,
)
from sqlalchemy.dialects.postgresql import JSONB
from sqlalchemy.orm import Mapped, mapped_column, relationship

from src.db.base import Base


def _utcnow() -> datetime:
    return datetime.now(timezone.utc)


class League(Base):
    __tablename__ = "leagues"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    code: Mapped[str] = mapped_column(String(20), unique=True, nullable=False)
    name: Mapped[str] = mapped_column(String(100), nullable=False)
    country: Mapped[str | None] = mapped_column(String(50))
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=_utcnow)

    matches: Mapped[list["Match"]] = relationship(back_populates="league")


class Team(Base):
    __tablename__ = "teams"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    name: Mapped[str] = mapped_column(String(120), unique=True, nullable=False)
    name_zh: Mapped[str | None] = mapped_column(String(60))
    team_type: Mapped[str] = mapped_column(String(20), default="club")
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=_utcnow)

    home_matches: Mapped[list["Match"]] = relationship(foreign_keys="Match.home_team_id", back_populates="home_team")
    away_matches: Mapped[list["Match"]] = relationship(foreign_keys="Match.away_team_id", back_populates="away_team")


class Match(Base):
    __tablename__ = "matches"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    league_id: Mapped[int] = mapped_column(ForeignKey("leagues.id"), nullable=False)
    season: Mapped[str | None] = mapped_column(String(12))
    home_team_id: Mapped[int] = mapped_column(ForeignKey("teams.id"), nullable=False)
    away_team_id: Mapped[int] = mapped_column(ForeignKey("teams.id"), nullable=False)
    match_date: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
    match_date_date: Mapped[date] = mapped_column(
        "match_date_date",
        Date,
        nullable=False,
        index=True,
    )
    match_status: Mapped[str] = mapped_column(String(20), default="scheduled")
    home_goals: Mapped[int | None] = mapped_column(Integer)
    away_goals: Mapped[int | None] = mapped_column(Integer)
    home_ht_goals: Mapped[int | None] = mapped_column(Integer)
    away_ht_goals: Mapped[int | None] = mapped_column(Integer)
    match_stage: Mapped[str | None] = mapped_column(String(100))
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=_utcnow)
    updated_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=_utcnow, onupdate=_utcnow)

    league: Mapped[League] = relationship(back_populates="matches", lazy="selectin")
    # lazy="selectin": 这些关系在业务里几乎总是一起读取(切片/回测/展示)。
    # 默认的 lazy="select" 在 async SQLAlchemy 下,于 session 之外或未显式
    # eager-load 时访问会抛 MissingGreenlet —— 已因此导致 form/stats/h2h
    # 三个专家切片静默失败。统一改为预加载,从根上消除这类问题。
    home_team: Mapped[Team] = relationship(
        foreign_keys=[home_team_id], back_populates="home_matches", lazy="selectin"
    )
    away_team: Mapped[Team] = relationship(
        foreign_keys=[away_team_id], back_populates="away_matches", lazy="selectin"
    )
    stats: Mapped["MatchStats | None"] = relationship(
        back_populates="match", cascade="all, delete-orphan", lazy="selectin"
    )
    predictions: Mapped[list["Prediction"]] = relationship(back_populates="match", cascade="all, delete-orphan")

    __table_args__ = (
        Index("ix_matches_league_date", "league_id", match_date.desc()),
        Index("ix_matches_home_date", "home_team_id", match_date.desc()),
        Index("ix_matches_away_date", "away_team_id", match_date.desc()),
        Index("ix_matches_status_date", "match_status", match_date.desc()),
        Index(
            "ix_matches_unique",
            "league_id",
            "home_team_id",
            "away_team_id",
            "match_date_date",
            unique=True,
        ),
    )


class MatchStats(Base):
    __tablename__ = "match_stats"

    match_id: Mapped[int] = mapped_column(ForeignKey("matches.id", ondelete="CASCADE"), primary_key=True)
    home_xg: Mapped[float | None] = mapped_column(Float)
    away_xg: Mapped[float | None] = mapped_column(Float)
    home_shots: Mapped[int | None] = mapped_column(Integer)
    away_shots: Mapped[int | None] = mapped_column(Integer)
    home_shots_on_target: Mapped[int | None] = mapped_column(Integer)
    away_shots_on_target: Mapped[int | None] = mapped_column(Integer)
    home_corners: Mapped[int | None] = mapped_column(Integer)
    away_corners: Mapped[int | None] = mapped_column(Integer)
    home_possession: Mapped[float | None] = mapped_column(Float)
    home_yellow_cards: Mapped[int | None] = mapped_column(Integer)
    away_yellow_cards: Mapped[int | None] = mapped_column(Integer)
    home_red_cards: Mapped[int | None] = mapped_column(Integer)
    away_red_cards: Mapped[int | None] = mapped_column(Integer)
    updated_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=_utcnow, onupdate=_utcnow)
    # 数据血缘:追踪统计数据的来源和可用时间
    source: Mapped[str | None] = mapped_column(String(30))  # bzzoiro / understat
    source_record_id: Mapped[str | None] = mapped_column(String(100))
    retrieved_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
    available_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))

    match: Mapped[Match] = relationship(back_populates="stats")

    __table_args__ = (
        # 数据血缘时间过滤查询用(按 available_at 取「赛前已可得」的统计)
        Index("ix_match_stats_available_at", "available_at"),
    )


class Injury(Base):
    """球员伤停记录(api-football 数据源)。"""
    __tablename__ = "injuries"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    player_id: Mapped[int | None] = mapped_column(Integer, index=True)
    player_name: Mapped[str] = mapped_column(String(120), nullable=False)
    team_id: Mapped[int | None] = mapped_column(ForeignKey("teams.id"), index=True)
    fixture_id: Mapped[int | None] = mapped_column(Integer)
    league_id: Mapped[int | None] = mapped_column(Integer)
    injury_type: Mapped[str | None] = mapped_column(String(50))  # Missing Fixture / Suspended
    reason: Mapped[str | None] = mapped_column(String(200))
    injury_date: Mapped[date | None] = mapped_column(Date, index=True)
    return_date: Mapped[date | None] = mapped_column(Date)
    retrieved_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=_utcnow)

    team: Mapped["Team | None"] = relationship()

    __table_args__ = (
        Index("ix_injuries_player_fixture", "player_id", "fixture_id", "injury_type", unique=True),
        Index("ix_injuries_team_date", "team_id", "injury_date"),
    )


class Prediction(Base):
    __tablename__ = "predictions"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    match_id: Mapped[int] = mapped_column(ForeignKey("matches.id"), nullable=False)
    provider: Mapped[str] = mapped_column(String(30), nullable=False)
    model: Mapped[str] = mapped_column(String(80), nullable=False)
    prompt_version: Mapped[str] = mapped_column(String(20), nullable=False, default="v1")
    prompt_tokens: Mapped[int | None] = mapped_column(Integer)
    completion_tokens: Mapped[int | None] = mapped_column(Integer)
    latency_ms: Mapped[int | None] = mapped_column(Integer)
    pred_home_goals: Mapped[float | None] = mapped_column(Float)
    pred_away_goals: Mapped[float | None] = mapped_column(Float)
    pred_1x2: Mapped[str | None] = mapped_column(String(3))
    subjective_confidence: Mapped[float | None] = mapped_column(Float)  # LLM 主观置信度,非概率
    reasoning: Mapped[str | None] = mapped_column(Text)
    raw_response: Mapped[dict | None] = mapped_column(JSONB)
    # multi-agent 模式: 各专家报告
    mode: Mapped[str] = mapped_column(String(20), nullable=False, default="single")
    agent_outputs: Mapped[dict | None] = mapped_column(JSONB)
    # 预测状态: success / failed / degraded
    status: Mapped[str] = mapped_column(String(20), nullable=False, default="success")
    # 时间语义:区分比赛时间、预测创建时间、数据截止时间
    match_kickoff_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
    prediction_created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=_utcnow)
    prediction_cutoff_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
    input_hash: Mapped[str | None] = mapped_column(String(64))
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=_utcnow)
    actual_home_goals: Mapped[int | None] = mapped_column(Integer)
    actual_away_goals: Mapped[int | None] = mapped_column(Integer)
    settled: Mapped[bool] = mapped_column(Boolean, default=False)

    match: Mapped[Match] = relationship(back_populates="predictions")

    __table_args__ = (
        Index("ix_predictions_match", "match_id"),
        Index("ix_predictions_provider_model", "provider", "model"),
        # 数据截止时间过滤查询用(按 prediction_cutoff_at 取「赛前已生成」的预测)
        Index("ix_predictions_cutoff_at", "prediction_cutoff_at"),
        # 数据库级约束:最后一道防线
        CheckConstraint("pred_home_goals >= 0", name="ck_pred_home_goals_nonneg"),
        CheckConstraint("pred_away_goals >= 0", name="ck_pred_away_goals_nonneg"),
        CheckConstraint("subjective_confidence >= 0 AND subjective_confidence <= 1", name="ck_confidence_range"),
        CheckConstraint("pred_1x2 IN ('1', 'X', '2')", name="ck_pred_1x2_enum"),
        CheckConstraint("mode IN ('single', 'multi')", name="ck_mode_enum"),
        CheckConstraint("status IN ('success', 'failed', 'degraded')", name="ck_status_enum"),
    )