from __future__ import annotations

from datetime import datetime
from typing import Any

from sqlalchemy import DateTime, ForeignKey, Index, JSON, String, Text, UniqueConstraint
from sqlalchemy.orm import Mapped, mapped_column, relationship

from iti.db import Base, IdMixin, TimestampMixin


class ExchangeTemplateModel(Base, IdMixin, TimestampMixin):
    __tablename__ = "exchange_templates"

    code: Mapped[str] = mapped_column(String(128), unique=True, index=True, comment="模板编码")
    name: Mapped[str] = mapped_column(String(255), comment="模板名称")
    template_kind: Mapped[str] = mapped_column(String(32), index=True, comment="模板类型")
    entity: Mapped[str] = mapped_column(String(128), index=True, comment="业务实体")
    status: Mapped[str] = mapped_column(String(32), default="draft", index=True, comment="状态")
    description: Mapped[str | None] = mapped_column(Text, nullable=True, comment="说明")
    current_version: Mapped[str | None] = mapped_column(
        String(64), nullable=True, index=True, comment="当前版本"
    )
    meta: Mapped[dict[str, Any]] = mapped_column(JSON, default=dict, comment="扩展配置")

    versions: Mapped[list["ExchangeTemplateVersionModel"]] = relationship(
        back_populates="template",
        cascade="all, delete-orphan",
    )


class ExchangeTemplateVersionModel(Base, IdMixin, TimestampMixin):
    __tablename__ = "exchange_template_versions"
    __table_args__ = (
        UniqueConstraint("template_id", "version", name="uq_exchange_template_versions_template_version"),
        Index("ix_exchange_template_versions_template_id_version", "template_id", "version"),
    )

    template_id: Mapped[str] = mapped_column(
        String(36),
        ForeignKey("exchange_templates.id", ondelete="CASCADE"),
        index=True,
        comment="模板ID",
    )
    version: Mapped[str] = mapped_column(String(64), comment="版本号")
    template_kind: Mapped[str] = mapped_column(String(32), index=True, comment="模板类型")
    published_at: Mapped[datetime | None] = mapped_column(
        DateTime,
        nullable=True,
        comment="发布时间",
    )
    file_key: Mapped[str | None] = mapped_column(String(512), nullable=True, comment="模板文件")
    checksum: Mapped[str | None] = mapped_column(String(128), nullable=True, comment="校验值")
    bindings: Mapped[list[dict[str, Any]]] = mapped_column(JSON, default=list, comment="绑定配置")
    fields: Mapped[list[dict[str, Any]]] = mapped_column(JSON, default=list, comment="字段定义")
    placeholders: Mapped[list[dict[str, Any]]] = mapped_column(JSON, default=list, comment="占位符定义")
    meta: Mapped[dict[str, Any]] = mapped_column(JSON, default=dict, comment="扩展配置")

    template: Mapped["ExchangeTemplateModel"] = relationship(back_populates="versions")


class ExchangeTaskModel(Base, IdMixin, TimestampMixin):
    __tablename__ = "exchange_tasks"
    __table_args__ = (
        Index("ix_exchange_tasks_template_id_kind_status", "template_id", "task_kind", "status"),
        Index("ix_exchange_tasks_version_id", "template_version_id"),
    )

    template_id: Mapped[str | None] = mapped_column(
        String(36),
        ForeignKey("exchange_templates.id", ondelete="SET NULL"),
        nullable=True,
        index=True,
        comment="模板ID",
    )
    template_version_id: Mapped[str | None] = mapped_column(
        String(36),
        ForeignKey("exchange_template_versions.id", ondelete="SET NULL"),
        nullable=True,
        index=True,
        comment="模板版本ID",
    )
    task_kind: Mapped[str] = mapped_column(String(32), index=True, comment="任务类型")
    status: Mapped[str] = mapped_column(String(32), default="pending", index=True, comment="状态")
    requested_by: Mapped[str | None] = mapped_column(String(36), nullable=True, index=True, comment="发起人")
    storage_key: Mapped[str | None] = mapped_column(String(512), nullable=True, comment="任务文件")
    checksum: Mapped[str | None] = mapped_column(String(128), nullable=True, comment="校验值")
    error_count: Mapped[int] = mapped_column(default=0, comment="错误数")
    success_count: Mapped[int] = mapped_column(default=0, comment="成功数")
    failed_count: Mapped[int] = mapped_column(default=0, comment="失败数")
    message: Mapped[str | None] = mapped_column(Text, nullable=True, comment="消息")
    input_payload: Mapped[dict[str, Any]] = mapped_column(JSON, default=dict, comment="输入参数")
    result_payload: Mapped[dict[str, Any]] = mapped_column(JSON, default=dict, comment="输出结果")
    started_at: Mapped[datetime | None] = mapped_column(DateTime, nullable=True, comment="开始时间")
    finished_at: Mapped[datetime | None] = mapped_column(DateTime, nullable=True, comment="结束时间")
    meta: Mapped[dict[str, Any]] = mapped_column(JSON, default=dict, comment="扩展配置")

    template: Mapped["ExchangeTemplateModel"] = relationship(
        foreign_keys=[template_id]
    )
    version: Mapped["ExchangeTemplateVersionModel"] = relationship(
        foreign_keys=[template_version_id]
    )
    rows: Mapped[list["ExchangeTaskRowModel"]] = relationship(
        back_populates="task",
        cascade="all, delete-orphan",
    )


class ExchangeTaskRowModel(Base, IdMixin, TimestampMixin):
    __tablename__ = "exchange_task_rows"
    __table_args__ = (
        UniqueConstraint("task_id", "row_index", name="uq_exchange_task_rows_task_row"),
        Index("ix_exchange_task_rows_task_id_status", "task_id", "status"),
    )

    task_id: Mapped[str] = mapped_column(
        String(36),
        ForeignKey("exchange_tasks.id", ondelete="CASCADE"),
        index=True,
        comment="任务ID",
    )
    row_index: Mapped[int] = mapped_column(comment="行号")
    status: Mapped[str] = mapped_column(String(32), default="pending", index=True, comment="状态")
    data: Mapped[dict[str, Any]] = mapped_column(JSON, default=dict, comment="原始数据")
    message: Mapped[str | None] = mapped_column(Text, nullable=True, comment="错误信息")
    result: Mapped[dict[str, Any]] = mapped_column(JSON, default=dict, comment="结果数据")

    task: Mapped["ExchangeTaskModel"] = relationship(back_populates="rows")