"""Module for contract."""

from __future__ import annotations

import contextlib
from typing import TYPE_CHECKING, Any, ClassVar

from django.db import models
from django.utils import timezone
from django.utils.translation import gettext_lazy as _

from apps.core.models.enums import CaseType

if TYPE_CHECKING:
    from django.db.models.fields.related_descriptors import RelatedManager

    from apps.cases.models import Case

    from .client_payment import ClientPaymentRecord
    from .finalized_material import FinalizedMaterial
    from .finance import ContractFinanceLog
    from .folder_binding import ContractFolderBinding
    from .party import ContractAssignment, ContractParty
    from .payment import ContractPayment
    from .supplementary import SupplementaryAgreement


class ContractStatus(models.TextChoices):
    ACTIVE = "active", _("在办")
    CLOSED = "closed", _("已结案")
    ARCHIVED = "archived", _("已归档")


class FeeMode(models.TextChoices):
    FIXED = "FIXED", _("固定收费")
    SEMI_RISK = "SEMI_RISK", _("半风险收费")
    FULL_RISK = "FULL_RISK", _("全风险收费")
    CUSTOM = "CUSTOM", _("自定义")


class Contract(models.Model):
    id: int
    name: models.CharField = models.CharField(max_length=100, verbose_name=_("合同名称"))
    case_type: models.CharField = models.CharField(max_length=32, choices=CaseType.choices, verbose_name=_("合同类型"))
    status: models.CharField = models.CharField(
        max_length=32, choices=ContractStatus.choices, default=ContractStatus.ACTIVE, verbose_name=_("合同状态")
    )
    specified_date: models.DateField = models.DateField(default=timezone.localdate, verbose_name=_("指定日期"))
    start_date: models.DateField = models.DateField(blank=True, null=True, verbose_name=_("开始日期"))
    end_date: models.DateField = models.DateField(blank=True, null=True, verbose_name=_("结束日期"))
    is_archived: models.BooleanField = models.BooleanField(default=False, verbose_name=_("是否已建档"))
    filing_number: models.CharField = models.CharField(
        max_length=50,
        blank=True,
        null=True,
        unique=True,
        verbose_name=_("建档编号"),
        help_text=_("格式: {年份}_{合同类型}_{HT}_{序号}"),
    )
    fee_mode: models.CharField = models.CharField(
        max_length=16, choices=FeeMode.choices, default=FeeMode.FIXED, verbose_name=_("收费模式")
    )
    fixed_amount: models.DecimalField = models.DecimalField(
        max_digits=14, decimal_places=2, blank=True, null=True, verbose_name=_("固定/前期律师费")
    )
    risk_rate: models.DecimalField = models.DecimalField(
        max_digits=5, decimal_places=2, blank=True, null=True, verbose_name=_("风险比例(%)")
    )
    custom_terms: models.TextField = models.TextField(blank=True, null=True, verbose_name=_("自定义收费条款"))
    law_firm_oa_url: models.URLField = models.URLField(
        max_length=500,
        blank=True,
        null=True,
        verbose_name=_("律所OA链接"),
        help_text=_("跳转至律所OA系统中该合同的页面"),
    )
    law_firm_oa_case_number: models.CharField = models.CharField(
        max_length=100,
        blank=True,
        null=True,
        verbose_name=_("律所OA案件编号"),
        help_text=_("律所OA系统中的案件编号"),
    )
    representation_stages: Any = models.JSONField(default=list, blank=True, verbose_name=_("代理阶段"))

    if TYPE_CHECKING:
        cases: RelatedManager[Case]
        finance_logs: RelatedManager[ContractFinanceLog]
        folder_binding: ContractFolderBinding
        contract_parties: RelatedManager[ContractParty]
        assignments: RelatedManager[ContractAssignment]
        payments: RelatedManager[ContractPayment]
        supplementary_agreements: RelatedManager[SupplementaryAgreement]
        finalized_materials: RelatedManager[FinalizedMaterial]
        client_payment_records: RelatedManager[ClientPaymentRecord]

    class Meta:
        verbose_name = _("合同")
        verbose_name_plural = _("合同")
        indexes: ClassVar = [
            # 单字段索引 - 用于基本过滤
            models.Index(fields=["case_type"]),
            models.Index(fields=["status"]),
            models.Index(fields=["is_archived"]),
            models.Index(fields=["specified_date"]),
            models.Index(fields=["-specified_date"]),
            models.Index(fields=["filing_number"]),
            # 复合索引 - 用于常见的组合查询
            # 按案件类型和状态查询(常用于列表过滤)
            models.Index(fields=["case_type", "status"]),
            # 按状态和指定日期查询(常用于时间范围过滤)
            models.Index(fields=["status", "-specified_date"]),
            # 按是否建档和指定日期查询(常用于归档管理)
            models.Index(fields=["is_archived", "-specified_date"]),
            # 按案件类型、状态和指定日期查询(常用于复杂过滤)
            models.Index(fields=["case_type", "status", "-specified_date"]),
        ]

    def __str__(self) -> str:
        return str(self.name)

    def clean(self) -> None:
        from apps.contracts.validators import normalize_representation_stages
        from apps.core.exceptions import ValidationException

        ctype = getattr(self, "case_type", None)
        rep = getattr(self, "representation_stages", None)
        with contextlib.suppress(ValidationException):
            self.representation_stages = normalize_representation_stages(ctype, rep, strict=False)