from __future__ import annotations

from datetime import datetime
from typing import Any, Literal

from pydantic import BaseModel, ConfigDict, Field, field_validator


RETENTION_DAY_KEYS = (
    "raw_campaign_json_retention_days",
    "generated_eml_retention_days",
    "stored_report_detail_retention_days",
    "mock_mailbox_retention_days",
    "audit_detail_retention_days",
)


RETENTION_POLICY_FIELD_KEYS = (
    "store_raw_campaign_json",
    *RETENTION_DAY_KEYS,
    "audit_detail_level",
)


def default_allow_lower_level_limits() -> dict[str, bool]:
    return {key: True for key in RETENTION_POLICY_FIELD_KEYS}


def normalize_allow_lower_level_limits(value: Any, *, fill_defaults: bool) -> dict[str, bool] | None:
    if value in (None, ""):
        return default_allow_lower_level_limits() if fill_defaults else None
    if not isinstance(value, dict):
        raise ValueError("allow_lower_level_limits must be an object")
    normalized = default_allow_lower_level_limits() if fill_defaults else {}
    for key, allowed in value.items():
        clean_key = str(key)
        if clean_key not in RETENTION_POLICY_FIELD_KEYS:
            raise ValueError(f"Unknown retention policy field: {clean_key}")
        normalized[clean_key] = bool(allowed)
    return normalized


class PolicySourceStepItem(BaseModel):
    scope_type: str
    scope_id: str | None = None
    path: str
    label: str
    applied_fields: list[str] = Field(default_factory=list)
    policy: dict[str, Any] = Field(default_factory=dict)


class PrivacyRetentionPolicyItem(BaseModel):
    model_config = ConfigDict(extra="forbid")

    store_raw_campaign_json: bool = True
    raw_campaign_json_retention_days: int | None = Field(default=None, ge=0)
    generated_eml_retention_days: int | None = Field(default=None, ge=0)
    stored_report_detail_retention_days: int | None = Field(default=None, ge=0)
    mock_mailbox_retention_days: int | None = Field(default=None, ge=0)
    audit_detail_retention_days: int | None = Field(default=None, ge=0)
    audit_detail_level: Literal["full", "redacted", "minimal"] = "full"
    allow_lower_level_limits: dict[str, bool] = Field(default_factory=default_allow_lower_level_limits)

    @field_validator("allow_lower_level_limits", mode="before")
    @classmethod
    def _normalize_allow_lower_level_limits(cls, value: Any) -> Any:
        return normalize_allow_lower_level_limits(value, fill_defaults=True)


class PrivacyRetentionPolicyPatchItem(BaseModel):
    model_config = ConfigDict(extra="forbid")

    store_raw_campaign_json: bool | None = None
    raw_campaign_json_retention_days: int | None = Field(default=None, ge=0)
    generated_eml_retention_days: int | None = Field(default=None, ge=0)
    stored_report_detail_retention_days: int | None = Field(default=None, ge=0)
    mock_mailbox_retention_days: int | None = Field(default=None, ge=0)
    audit_detail_retention_days: int | None = Field(default=None, ge=0)
    audit_detail_level: Literal["full", "redacted", "minimal"] | None = None
    allow_lower_level_limits: dict[str, bool] | None = None

    @field_validator("allow_lower_level_limits", mode="before")
    @classmethod
    def _normalize_allow_lower_level_limits(cls, value: Any) -> Any:
        return normalize_allow_lower_level_limits(value, fill_defaults=False)


class PrivacyRetentionPolicyScopeRequest(BaseModel):
    model_config = ConfigDict(extra="forbid")

    policy: PrivacyRetentionPolicyPatchItem = Field(default_factory=PrivacyRetentionPolicyPatchItem)
    change_request_id: str | None = None


class PrivacyRetentionPolicyScopeResponse(BaseModel):
    scope_type: Literal["system", "tenant", "user", "group", "campaign"]
    scope_id: str | None = None
    policy: dict[str, Any]
    effective_policy: PrivacyRetentionPolicyItem
    parent_policy: PrivacyRetentionPolicyItem | None = None
    effective_policy_sources: list[PolicySourceStepItem] = Field(default_factory=list)
    parent_policy_sources: list[PolicySourceStepItem] = Field(default_factory=list)


class PolicyDecisionItem(BaseModel):
    allowed: bool
    reason: str | None = None
    source_path: list[PolicySourceStepItem] = Field(default_factory=list)
    requirements: list[str] = Field(default_factory=list)
    details: dict[str, Any] = Field(default_factory=dict)


class PrivacyRetentionPolicyExplainResponse(BaseModel):
    scope_type: Literal["system", "tenant", "user", "group", "campaign"]
    scope_id: str | None = None
    decision: PolicyDecisionItem
    effective_policy: PrivacyRetentionPolicyItem
    parent_policy: PrivacyRetentionPolicyItem | None = None
    effective_policy_sources: list[PolicySourceStepItem] = Field(default_factory=list)
    parent_policy_sources: list[PolicySourceStepItem] = Field(default_factory=list)
    blocked_fields: list[str] = Field(default_factory=list)


class PrivacyRetentionPolicySimulationResponse(BaseModel):
    scope_type: Literal["system", "tenant", "user", "group", "campaign"]
    scope_id: str | None = None
    simulation: dict[str, Any]


class RetentionRunRequest(BaseModel):
    model_config = ConfigDict(extra="forbid")

    dry_run: bool = True


class RetentionRunResponse(BaseModel):
    result: dict[str, Any]