"""Typed analysis packet contracts for analysis-style replies."""

from __future__ import annotations

from typing import Annotated, Any, Literal

from pydantic import BaseModel, ConfigDict, Field, TypeAdapter


AnalysisFocusStance = Literal[
    "better_fit",
    "not_fit",
    "anchor",
    "blocked",
    "dependent",
    "relevant",
]


class AnalysisFocusObject(BaseModel):
    model_config = ConfigDict(extra="ignore")

    name: str
    kind: str = "unknown"
    stance: AnalysisFocusStance = "relevant"
    reason: str


class AnalysisPacketBase(BaseModel):
    model_config = ConfigDict(extra="ignore")

    packet_version: str = "v1"
    packet_type: str
    conclusion: str
    focus_objects: list[AnalysisFocusObject] = Field(default_factory=list, max_length=2)
    next_step: str | None = None


class ProjectFitAnalysisPacket(AnalysisPacketBase):
    packet_type: Literal["project_fit_analysis"] = "project_fit_analysis"
    fit_verdict: Literal["fit_now", "fit_later", "not_fit_yet", "uncertain"]
    current_subject: str | None = None
    candidate_position: str | None = None
    rejected_position: str | None = None
    preferred_layer: str | None = None
    rejected_layer: str | None = None
    reason_chain: list[str] = Field(default_factory=list, max_length=3)
    missing_mapping: str


class ExternalImpactAnalysisPacket(AnalysisPacketBase):
    packet_type: Literal["external_impact_analysis"] = "external_impact_analysis"
    retrieval_status: Literal["evidence_found", "verifier_blocked", "no_relevant_results", "retrieval_failed"]
    impact_status: Literal["direct_match", "indirect_only", "no_direct_impact"]
    current_subject: str | None = None
    reason_chain: list[str] = Field(default_factory=list, max_length=3)
    anchor_objects: list[str] = Field(default_factory=list)
    blocked_reason_or_gap: str


class InternalExplainAnalysisPacket(AnalysisPacketBase):
    packet_type: Literal["internal_explain_analysis"] = "internal_explain_analysis"
    answer_contract: str | None = None
    current_subject: str | None = None
    reason_chain: list[str] = Field(default_factory=list, max_length=3)
    resolved_target: str | None = None
    evidence_gap_or_uncertainty: str | None = None


class FollowupExplainAnalysisPacket(AnalysisPacketBase):
    packet_type: Literal["followup_explain_analysis"] = "followup_explain_analysis"
    anchor_kind: str | None = None
    continuation_kind: str | None = None
    clarification_state: str | None = None
    missing_mapping: str | None = None


AnalysisPacket = Annotated[
    ProjectFitAnalysisPacket
    | ExternalImpactAnalysisPacket
    | InternalExplainAnalysisPacket
    | FollowupExplainAnalysisPacket,
    Field(discriminator="packet_type"),
]

_ANALYSIS_PACKET_ADAPTER = TypeAdapter(AnalysisPacket)


def coerce_analysis_packet(value: Any) -> AnalysisPacket | None:
    if value is None:
        return None
    if isinstance(
        value,
        (
            ProjectFitAnalysisPacket,
            ExternalImpactAnalysisPacket,
            InternalExplainAnalysisPacket,
            FollowupExplainAnalysisPacket,
        ),
    ):
        return value
    if isinstance(value, dict):
        try:
            return _ANALYSIS_PACKET_ADAPTER.validate_python(value)
        except Exception:
            return None
    return None


def normalize_analysis_packet_payload(value: Any) -> dict[str, Any]:
    packet = coerce_analysis_packet(value)
    return packet.model_dump() if packet is not None else {}


__all__ = [
    "AnalysisFocusObject",
    "AnalysisPacket",
    "ExternalImpactAnalysisPacket",
    "FollowupExplainAnalysisPacket",
    "InternalExplainAnalysisPacket",
    "ProjectFitAnalysisPacket",
    "coerce_analysis_packet",
    "normalize_analysis_packet_payload",
]