from __future__ import annotations

from datetime import datetime
from typing import Any, Literal

from pydantic import BaseModel, ConfigDict, Field, model_validator


AddressImportFormat = Literal["csv", "xlsx", "ldif"]
AddressImportScope = Literal["user", "group", "tenant", "system"]

IMPORT_TARGET_FIELDS = frozenset(
    {
        "source_key",
        "display_name",
        "given_name",
        "family_name",
        "organization",
        "role_title",
        "note",
        "email",
        "phone",
        "street",
        "postal_code",
        "locality",
        "region",
        "country",
        "tags",
        "visibility",
    }
)


class AddressImportConfiguration(BaseModel):
    field_mappings: dict[str, str] = Field(default_factory=dict, max_length=40)
    delimiter: Literal[",", ";", "\t", "|"] = ","
    encoding: Literal["utf-8", "utf-8-sig", "cp1252", "latin-1"] = "utf-8-sig"
    header_row: int = Field(default=1, ge=1, le=100)
    sheet_name: str | None = Field(default=None, max_length=255)
    source_key_column: str | None = Field(default=None, max_length=255)
    duplicate_source_key_policy: Literal["reject", "first", "last"] = "reject"
    existing_contact_policy: Literal["update", "ignore", "reject"] = "update"
    blank_value_policy: Literal["ignore", "clear", "reject"] = "ignore"
    ldif_change_record_policy: Literal["reject", "ignore", "treat_add_as_entry"] = "reject"
    locale: str | None = Field(default=None, max_length=35)
    default_tags: list[str] = Field(default_factory=list, max_length=100)
    max_rows: int = Field(default=10_000, ge=1, le=10_000)

    @model_validator(mode="after")
    def validate_mappings(self) -> "AddressImportConfiguration":
        invalid = sorted(set(self.field_mappings).difference(IMPORT_TARGET_FIELDS))
        if invalid:
            raise ValueError(f"Unsupported address import target fields: {', '.join(invalid)}")
        for target, column in self.field_mappings.items():
            if not target.strip() or not column.strip():
                raise ValueError("Import mapping targets and source columns cannot be blank.")
        if "source_key" not in self.field_mappings and not self.source_key_column:
            raise ValueError("Address import profiles require a stable source-key column.")
        return self


class AddressImportProfileCreateRequest(BaseModel):
    scope_type: AddressImportScope = "tenant"
    scope_id: str | None = Field(default=None, max_length=36)
    name: str = Field(min_length=1, max_length=255)
    description: str | None = Field(default=None, max_length=4000)
    source_format: AddressImportFormat
    configuration: AddressImportConfiguration


class AddressImportProfileUpdateRequest(BaseModel):
    name: str | None = Field(default=None, min_length=1, max_length=255)
    description: str | None = Field(default=None, max_length=4000)
    configuration: AddressImportConfiguration | None = None


class AddressImportProfileResponse(BaseModel):
    model_config = ConfigDict(from_attributes=True)

    id: str
    profile_key: str
    version: int
    tenant_id: str | None = None
    scope_type: str
    scope_id: str | None = None
    name: str
    description: str | None = None
    source_format: str
    configuration: AddressImportConfiguration
    is_current: bool
    created_by_account_id: str | None = None
    superseded_at: datetime | None = None
    created_at: datetime
    updated_at: datetime


class AddressImportProfileListResponse(BaseModel):
    profiles: list[AddressImportProfileResponse] = Field(default_factory=list)


class AddressImportFilePayload(BaseModel):
    filename: str = Field(min_length=1, max_length=500)
    content_base64: str = Field(min_length=1, max_length=14_000_000)


class AddressImportPreviewRequest(AddressImportFilePayload):
    profile_id: str = Field(min_length=1, max_length=36)


class AddressImportEffectResponse(BaseModel):
    row_number: int
    action: Literal["create", "update", "conflict", "unchanged", "ignored"]
    source_key: str | None = None
    contact_id: str | None = None
    display_name: str | None = None
    changed_fields: list[str] = Field(default_factory=list)
    message: str | None = None


class AddressImportDiagnosticResponse(BaseModel):
    severity: Literal["info", "warning", "error"]
    code: str
    message: str
    row_number: int | None = None
    field: str | None = None
    details: dict[str, Any] = Field(default_factory=dict)


class AddressImportRunResponse(BaseModel):
    id: str
    address_book_id: str
    profile_id: str | None
    source_filename: str
    source_format: str
    input_hash: str
    plan_hash: str
    status: str
    row_count: int
    statistics: dict[str, int] = Field(default_factory=dict)
    diagnostics: list[AddressImportDiagnosticResponse] = Field(default_factory=list)
    effects: list[AddressImportEffectResponse] = Field(default_factory=list)
    can_apply: bool
    result_evidence: dict[str, Any] = Field(default_factory=dict)
    created_at: datetime
    updated_at: datetime
    applied_at: datetime | None = None
    rolled_back_at: datetime | None = None


class AddressImportCommitRequest(BaseModel):
    expected_plan_hash: str = Field(min_length=64, max_length=64)


class AddressImportRollbackRequest(BaseModel):
    expected_plan_hash: str = Field(min_length=64, max_length=64)
    reason: str = Field(min_length=3, max_length=2000)


__all__ = [
    "AddressImportCommitRequest",
    "AddressImportConfiguration",
    "AddressImportDiagnosticResponse",
    "AddressImportEffectResponse",
    "AddressImportFilePayload",
    "AddressImportFormat",
    "AddressImportPreviewRequest",
    "AddressImportProfileCreateRequest",
    "AddressImportProfileListResponse",
    "AddressImportProfileResponse",
    "AddressImportProfileUpdateRequest",
    "AddressImportRollbackRequest",
    "AddressImportRunResponse",
    "IMPORT_TARGET_FIELDS",
]