from datetime import datetime, timezone, time
from typing import Optional, Any
import enum

from sqlalchemy import (
    String, Integer, BigInteger, Text, Boolean, DateTime, Time,
    Float, JSON, ForeignKey, Enum, UniqueConstraint, Index
)
from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column, relationship


# ==========================================
# 0. 全局基类与枚举定义
# ==========================================

class Base(DeclarativeBase):
    """SQLAlchemy 2.0 声明式基类"""
    pass


class SourceType(str, enum.Enum):
    HOT_TREND = "HOT_TREND"
    RSS_FEED = "RSS_FEED"
    API = "API"


class TargetType(str, enum.Enum):
    EVENT = "EVENT"
    TREND = "TREND"
    ARTICLE = "ARTICLE"


class TaskStatus(str, enum.Enum):
    SUCCESS = "SUCCESS"
    ERROR = "ERROR"


class GenderType(str, enum.Enum):
    MALE = "MALE"
    FEMALE = "FEMALE"
    OTHER = "OTHER"
    UNKNOWN = "UNKNOWN"


def utcnow():
    """获取带UTC时区的当前时间 (推荐实践)"""
    return datetime.now(timezone.utc)


# ==========================================
# 模块一：信息源管理
# ==========================================
class InfoSource(Base):
    __tablename__ = "info_sources"

    id: Mapped[int] = mapped_column(primary_key=True, autoincrement=True)
    source_name: Mapped[str] = mapped_column(String(100), comment="信息源名称")
    source_type: Mapped[SourceType] = mapped_column(Enum(SourceType))
    home_url: Mapped[Optional[str]] = mapped_column(String(255))
    is_enabled: Mapped[bool] = mapped_column(Boolean, default=True)

    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)
    updated_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow, onupdate=utcnow)


# ==========================================
# 模块二：AI 语义聚类中枢 (大事件池)
# ==========================================
class UnifiedEvent(Base):
    __tablename__ = "unified_events"

    id: Mapped[int] = mapped_column(BigInteger, primary_key=True, autoincrement=True)
    unified_title: Mapped[str] = mapped_column(String(255), comment="AI统一标题")
    ai_comprehensive_summary: Mapped[Optional[str]] = mapped_column(Text, comment="AI全局深度总结")

    # SQLite 没有原生 Vector 类型，存为用逗号分隔的字符串或JSON，Postgres可换成 PGVector
    center_embedding: Mapped[Optional[str]] = mapped_column(Text, comment="中心向量")
    hot_score: Mapped[int] = mapped_column(Integer, default=0, comment="聚合热度得分")

    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)
    updated_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow, onupdate=utcnow)


# ==========================================
# 模块三：内容存储库 (热搜 & 新闻子节点)
# ==========================================
class TrendingEvent(Base):
    __tablename__ = "trending_events"
    __table_args__ = (
        UniqueConstraint("source_id", "external_id", name="idx_unique_external_trend"),
    )

    id: Mapped[int] = mapped_column(BigInteger, primary_key=True, autoincrement=True)
    source_id: Mapped[int] = mapped_column(ForeignKey("info_sources.id"))
    unified_event_id: Mapped[Optional[int]] = mapped_column(ForeignKey("unified_events.id"))

    external_id: Mapped[str] = mapped_column(String(32), comment="32位MD5哈希指纹防重")
    title_embedding: Mapped[Optional[str]] = mapped_column(Text)

    icon_url: Mapped[Optional[str]] = mapped_column(String(500))
    current_headline: Mapped[str] = mapped_column(String(255))
    event_url: Mapped[Optional[str]] = mapped_column(String(500))
    app_link: Mapped[Optional[str]] = mapped_column(String(500))
    current_ranking: Mapped[Optional[int]] = mapped_column(Integer)
    brief_snippet: Mapped[Optional[str]] = mapped_column(Text)

    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)
    updated_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow, onupdate=utcnow)


class NewsArticle(Base):
    __tablename__ = "news_articles"
    __table_args__ = (
        UniqueConstraint("source_id", "external_id", name="idx_unique_external_article"),
    )

    id: Mapped[int] = mapped_column(BigInteger, primary_key=True, autoincrement=True)
    source_id: Mapped[int] = mapped_column(ForeignKey("info_sources.id"))
    unified_event_id: Mapped[Optional[int]] = mapped_column(ForeignKey("unified_events.id"))

    external_id: Mapped[str] = mapped_column(String(32))
    title_embedding: Mapped[Optional[str]] = mapped_column(Text)

    cover_image_url: Mapped[Optional[str]] = mapped_column(String(500))
    article_title: Mapped[str] = mapped_column(String(255))
    article_url: Mapped[Optional[str]] = mapped_column(String(500))
    author_name: Mapped[Optional[str]] = mapped_column(String(100))
    original_summary: Mapped[Optional[str]] = mapped_column(Text)
    publish_time: Mapped[Optional[datetime]] = mapped_column(DateTime(timezone=True))

    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)
    updated_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow, onupdate=utcnow)


# ==========================================
# 模块四：热度与轨迹追踪
# ==========================================
class HeadlineRevision(Base):
    __tablename__ = "headline_revisions"

    id: Mapped[int] = mapped_column(BigInteger, primary_key=True, autoincrement=True)
    event_id: Mapped[int] = mapped_column(ForeignKey("trending_events.id"))
    previous_headline: Mapped[str] = mapped_column(String(255))
    revised_headline: Mapped[str] = mapped_column(String(255))

    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)


class RankingLog(Base):
    __tablename__ = "ranking_logs"
    __table_args__ = (
        Index("idx_event_time", "event_id", "observed_at"),
    )

    id: Mapped[int] = mapped_column(BigInteger, primary_key=True, autoincrement=True)
    event_id: Mapped[int] = mapped_column(ForeignKey("trending_events.id"))
    ranking_position: Mapped[int] = mapped_column(Integer)
    observed_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)

    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)


# ==========================================
# 模块五：多态话题与多态评论
# ==========================================
class ExtractedTopic(Base):
    __tablename__ = "extracted_topics"
    __table_args__ = (
        Index("idx_topic_keyword", "topic_keyword"),
        Index("idx_polymorphic_topics", "target_type", "target_id"),
    )

    id: Mapped[int] = mapped_column(BigInteger, primary_key=True, autoincrement=True)
    target_type: Mapped[TargetType] = mapped_column(Enum(TargetType))
    target_id: Mapped[int] = mapped_column(BigInteger)
    topic_keyword: Mapped[str] = mapped_column(String(100))
    relevance_score: Mapped[Optional[float]] = mapped_column(Float)

    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)


class DiscussionComment(Base):
    __tablename__ = "discussion_comments"
    __table_args__ = (
        Index("idx_polymorphic_comments", "target_type", "target_id"),
    )

    id: Mapped[int] = mapped_column(BigInteger, primary_key=True, autoincrement=True)
    target_type: Mapped[TargetType] = mapped_column(Enum(TargetType))
    target_id: Mapped[int] = mapped_column(BigInteger)

    commenter_name: Mapped[Optional[str]] = mapped_column(String(100))
    comment_content: Mapped[str] = mapped_column(Text)
    likes_count: Mapped[int] = mapped_column(Integer, default=0)
    external_comment_id: Mapped[Optional[str]] = mapped_column(String(32))
    comment_time: Mapped[Optional[datetime]] = mapped_column(DateTime(timezone=True))

    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)


# ==========================================
# 模块六：用户画像与多渠道高可用推送系统
# ==========================================
class AppUser(Base):
    __tablename__ = "app_users"

    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
    email: Mapped[str] = mapped_column(String(150), unique=True, index=True)
    password_hash: Mapped[Optional[str]] = mapped_column(String(255))

    nickname: Mapped[Optional[str]] = mapped_column(String(100))
    avatar_url: Mapped[Optional[str]] = mapped_column(String(500))
    gender: Mapped[GenderType] = mapped_column(Enum(GenderType), default=GenderType.UNKNOWN)

    # 核心：万能扩展收纳箱 (SQLite 完美支持通过 SQLAlchemy 存储 JSON)
    metadata_: Mapped[Optional[Any]] = mapped_column("metadata", JSON, comment="自定义扩展偏好")

    timezone: Mapped[str] = mapped_column(String(50), default="Asia/Shanghai")
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)
    updated_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow, onupdate=utcnow)


class UserPushEndpoint(Base):
    __tablename__ = "user_push_endpoints"
    __table_args__ = (
        UniqueConstraint("user_id", "channel_type", name="idx_unique_user_channel"),
    )

    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
    user_id: Mapped[int] = mapped_column(ForeignKey("app_users.id"))
    channel_type: Mapped[str] = mapped_column(String(50), comment="如 EMAIL, WECHAT")
    channel_account: Mapped[str] = mapped_column(String(255))
    is_active: Mapped[bool] = mapped_column(Boolean, default=True)
    priority_level: Mapped[int] = mapped_column(Integer, default=1, comment="1最高，降级重试")

    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)
    updated_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow, onupdate=utcnow)


class UserTopicPreference(Base):
    __tablename__ = "user_topic_preferences"
    __table_args__ = (
        UniqueConstraint("user_id", "interested_keyword", name="idx_unique_preference"),
    )

    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
    user_id: Mapped[int] = mapped_column(ForeignKey("app_users.id"))
    interested_keyword: Mapped[str] = mapped_column(String(100))

    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)


class UserDeliverySchedule(Base):
    __tablename__ = "user_delivery_schedules"
    __table_args__ = (
        UniqueConstraint("user_id", "delivery_time", name="idx_unique_schedule"),
    )

    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
    user_id: Mapped[int] = mapped_column(ForeignKey("app_users.id"))
    delivery_time: Mapped[time] = mapped_column(Time, comment="如 08:30:00")
    is_active: Mapped[bool] = mapped_column(Boolean, default=True)

    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)


class DeliveryHistory(Base):
    __tablename__ = "delivery_history"
    __table_args__ = (
        UniqueConstraint("user_id", "target_type", "target_id", name="idx_prevent_duplicate_push"),
    )

    id: Mapped[int] = mapped_column(BigInteger, primary_key=True, autoincrement=True)
    user_id: Mapped[int] = mapped_column(ForeignKey("app_users.id"))
    target_type: Mapped[TargetType] = mapped_column(Enum(TargetType))
    target_id: Mapped[int] = mapped_column(BigInteger)
    status: Mapped[TaskStatus] = mapped_column(Enum(TaskStatus))

    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)


# ==========================================
# 模块七：系统任务监控
# ==========================================
class DataSyncTask(Base):
    __tablename__ = "data_sync_tasks"

    id: Mapped[int] = mapped_column(BigInteger, primary_key=True, autoincrement=True)
    source_id: Mapped[int] = mapped_column(ForeignKey("info_sources.id"))
    items_fetched: Mapped[int] = mapped_column(Integer, default=0)
    task_status: Mapped[TaskStatus] = mapped_column(Enum(TaskStatus))
    error_trace: Mapped[Optional[str]] = mapped_column(Text)

    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)