"""Explicit snapshot and field-binding contracts for research producers."""

from typing import Literal

from pydantic import Field, model_validator

from ..backtests.contracts import SimulationSettings, Source
from ..preparations.contracts import PreparationReference
from ..schemas import Contract
from .expressions import PLACEHOLDER


class ResearchInputSelection(Contract):
    items: list[PreparationReference] = Field(min_length=1, max_length=1)


class InputPageArgs(Contract):
    input_id: str = Field(min_length=1, max_length=36)
    limit: int = Field(default=25, ge=1, le=100)
    offset: int = Field(default=0, ge=0)
    q: str = Field(default="", max_length=300)
    field_type: str | None = Field(default=None, max_length=100)


class FieldBinding(Contract):
    field_id: str = Field(min_length=1, max_length=200, pattern=r"^[A-Za-z_][A-Za-z0-9_]*$")
    field_type: Literal["MATRIX", "VECTOR", "GROUP"]


class ResearchCandidate(Contract):
    client_item_id: str = Field(min_length=1, max_length=100)
    expression_template: str = Field(min_length=1, max_length=20000)
    bindings: dict[str, FieldBinding] = Field(min_length=1, max_length=100)
    settings: SimulationSettings

    @model_validator(mode="after")
    def complete_bindings(self):
        placeholders = set(PLACEHOLDER.findall(self.expression_template))
        remainder = PLACEHOLDER.sub("", self.expression_template)
        if placeholders != set(self.bindings) or "{" in remainder or "}" in remainder:
            raise ValueError("模板占位符必须与字段绑定逐一对应，例如 rank({price})")
        return self


class ChatboxResearchInput(Contract):
    """Chatbox provenance is supplied by the server, never by model arguments."""

    name: str = Field(min_length=1, max_length=200)
    hypothesis: str = Field(min_length=1, max_length=2000)
    input_snapshot_id: str = Field(min_length=1, max_length=36)
    candidates: list[ResearchCandidate] = Field(min_length=1, max_length=100)

    @model_validator(mode="after")
    def unique_candidates(self):
        if len({item.client_item_id for item in self.candidates}) != len(self.candidates):
            raise ValueError("client_item_id 在候选集合内必须唯一")
        return self


class ResearchPreviewInput(ChatboxResearchInput):
    source: Source = Field(default_factory=Source)