"""Authoritative Memory contracts, independent of workflow decision kinds."""

from datetime import datetime
from typing import Literal, Self

from pydantic import BaseModel, ConfigDict, Field, model_validator

Family = Literal["domain_clarification", "sql_rule", "solved_question", "explained_error"]


class Dependency(BaseModel):
    model_config = ConfigDict(extra="forbid", str_strip_whitespace=True)
    database: str = Field(min_length=1, max_length=200)
    schema_name: str = Field(default="", max_length=200)
    table: str = Field(default="", max_length=200)
    column: str = Field(default="", max_length=200)

    @model_validator(mode="after")
    def structured(self) -> Self:
        if self.column and not self.table:
            raise ValueError("A column dependency requires a table")
        if self.table and not self.schema_name:
            raise ValueError("A table dependency requires a schema")
        return self


class LinkInput(BaseModel):
    model_config = ConfigDict(extra="forbid", str_strip_whitespace=True)
    target_id: str = Field(min_length=1, max_length=100)
    meaning: str = Field(min_length=1, max_length=1000)


class CardInput(BaseModel):
    model_config = ConfigDict(extra="forbid", str_strip_whitespace=True)
    family: Family
    subject: str = Field(min_length=1, max_length=1000)
    detail: str = Field(default="", max_length=50000)
    scope: str = Field(min_length=1, max_length=10000)
    rationale: str = Field(default="", max_length=10000)
    question: str = Field(default="", max_length=10000)
    sql: str = Field(default="", max_length=100000)
    concepts: list[str] = Field(default_factory=list, max_length=100)
    dependencies: list[Dependency] = Field(default_factory=list, max_length=200)
    links: list[LinkInput] = Field(default_factory=list, max_length=200)

    @model_validator(mode="after")
    def valid_family(self) -> Self:
        if self.family == "solved_question" and (not self.question or not self.sql):
            raise ValueError("A solved question requires its question and approved SQL")
        if self.family == "explained_error" and (not self.detail or not self.rationale):
            raise ValueError("An explained error requires a correction and rationale")
        if self.family != "solved_question" and self.sql:
            raise ValueError("Only solved questions carry exemplar SQL")
        if any(not c.strip() or len(c) > 200 for c in self.concepts):
            raise ValueError("Concepts must contain between 1 and 200 characters")
        if len({link.target_id for link in self.links}) != len(self.links):
            raise ValueError("Each linked destination must be unique")
        return self


class Card(CardInput):
    id: str
    workspace_id: str
    origin: Literal["manual", "workflow"]
    session_id: str | None = None
    decision_seq: int | None = None
    created_at: datetime
    updated_at: datetime
    revision: str
    indexed: bool = False


class CardQuery(BaseModel):
    model_config = ConfigDict(extra="forbid")
    q: str = Field(default="", max_length=1000)
    family: Family | None = None
    concept: str = Field(default="", max_length=200)
    database: str = Field(default="", max_length=200)
    table: str = Field(default="", max_length=200)
    column: str = Field(default="", max_length=200)
    origin: Literal["manual", "workflow"] | None = None
    updated_after: datetime | None = None
    updated_before: datetime | None = None
    page: int = Field(default=1, ge=1)
    page_size: int = Field(default=25, ge=1, le=100)
    sort: Literal["updated_at", "created_at", "subject", "family"] = "updated_at"
    direction: Literal["asc", "desc"] = "desc"


class MemoryError(Exception):
    code = "memory_operation_failed"
    status = 500


class MemoryUnavailable(MemoryError):
    code = "memory_unavailable"
    status = 503


class MemoryNotFound(MemoryError):
    code = "memory_not_found"
    status = 404


class MemoryForbidden(MemoryError):
    code = "memory_forbidden"
    status = 403


class MemoryConflict(MemoryError):
    code = "memory_conflict"
    status = 409