from __future__ import annotations

from dataclasses import dataclass, field

from repo_registry.core.models import ObservedFact, Repository, SourceReference


@dataclass(frozen=True)
class CandidateEvidenceDraft:
    type: str
    reference: str
    strength: str
    source_refs: list[SourceReference]


@dataclass(frozen=True)
class CandidateFeatureDraft:
    name: str
    type: str
    location: str
    confidence: float
    source_refs: list[SourceReference]


@dataclass(frozen=True)
class CandidateCapabilityDraft:
    name: str
    description: str
    inputs: list[str]
    outputs: list[str]
    confidence: float
    source_refs: list[SourceReference]
    features: list[CandidateFeatureDraft] = field(default_factory=list)
    evidence: list[CandidateEvidenceDraft] = field(default_factory=list)


@dataclass(frozen=True)
class CandidateAbilityDraft:
    name: str
    description: str
    confidence: float
    source_refs: list[SourceReference]
    capabilities: list[CandidateCapabilityDraft] = field(default_factory=list)


class CandidateGraphGenerator:
    """Build conservative review candidates from observed facts."""

    def generate(
        self,
        repository: Repository,
        facts: list[ObservedFact],
    ) -> list[CandidateAbilityDraft]:
        if not facts:
            return []

        docs = self._facts(facts, "documentation")
        tests = self._facts(facts, "test")
        examples = self._facts(facts, "example")
        interfaces = self._facts(facts, "interface")
        manifests = self._facts(facts, "manifest")
        frameworks = self._facts(facts, "framework")
        languages = self._facts(facts, "language")

        ability_sources = docs or manifests or languages
        ability = CandidateAbilityDraft(
            name=f"Review {repository.name} Repository Usefulness",
            description=(
                "Candidate usefulness summary generated from observed repository "
                "documentation, manifests, languages, and interfaces. This is a "
                "review seed, not an asserted domain ability."
            ),
            confidence=0.55 if docs else 0.35,
            source_refs=self._source_refs(ability_sources),
            capabilities=[],
        )

        capabilities: list[CandidateCapabilityDraft] = []
        if interfaces:
            capabilities.append(self._interface_capability(interfaces, tests, examples, docs))
        if manifests or frameworks or languages:
            capabilities.append(
                CandidateCapabilityDraft(
                    name="Describe Repository Structure",
                    description=(
                        "Summarize detected languages, package manifests, and framework "
                        "hints as structural context for review."
                    ),
                    inputs=[],
                    outputs=["repository structure summary"],
                    confidence=0.6,
                    source_refs=self._source_refs(manifests + frameworks + languages),
                    evidence=self._evidence(tests, examples, docs),
                )
            )

        return [
            CandidateAbilityDraft(
                name=ability.name,
                description=ability.description,
                confidence=ability.confidence,
                source_refs=ability.source_refs,
                capabilities=capabilities,
            )
        ]

    def _interface_capability(
        self,
        interfaces: list[ObservedFact],
        tests: list[ObservedFact],
        examples: list[ObservedFact],
        docs: list[ObservedFact],
    ) -> CandidateCapabilityDraft:
        features = [
            CandidateFeatureDraft(
                name=fact.value or fact.name,
                type=self._feature_type(fact),
                location=fact.path,
                confidence=0.65 if fact.value else 0.45,
                source_refs=self._source_refs([fact]),
            )
            for fact in interfaces
        ]
        return CandidateCapabilityDraft(
            name="Expose Repository Interface",
            description=(
                "Expose one or more likely user-facing API or CLI entry points. "
                "Review is required to name the concrete domain behavior."
            ),
            inputs=[],
            outputs=["callable interface"],
            confidence=0.65,
            source_refs=self._source_refs(interfaces),
            features=features,
            evidence=self._evidence(tests, examples, docs),
        )

    def _evidence(
        self,
        tests: list[ObservedFact],
        examples: list[ObservedFact],
        docs: list[ObservedFact],
    ) -> list[CandidateEvidenceDraft]:
        evidence: list[CandidateEvidenceDraft] = []
        for fact in tests:
            evidence.append(
                CandidateEvidenceDraft(
                    type="test",
                    reference=fact.path,
                    strength="strong",
                    source_refs=self._source_refs([fact]),
                )
            )
        for fact in examples:
            evidence.append(
                CandidateEvidenceDraft(
                    type="example",
                    reference=fact.path,
                    strength="strong",
                    source_refs=self._source_refs([fact]),
                )
            )
        for fact in docs:
            evidence.append(
                CandidateEvidenceDraft(
                    type="documentation",
                    reference=fact.path,
                    strength="medium",
                    source_refs=self._source_refs([fact]),
                )
            )
        return evidence

    def _feature_type(self, fact: ObservedFact) -> str:
        lower = f"{fact.name} {fact.path} {fact.value}".lower()
        if "cli" in lower or "command" in lower:
            return "CLI"
        if "api" in lower or "route" in lower or "@app." in lower or "@router." in lower:
            return "API"
        return "interface"

    def _facts(self, facts: list[ObservedFact], kind: str) -> list[ObservedFact]:
        return [fact for fact in facts if fact.kind == kind]

    def _source_refs(self, facts: list[ObservedFact]) -> list[SourceReference]:
        return [
            SourceReference(
                fact_id=fact.id,
                path=fact.path,
                kind=fact.kind,
                name=fact.name,
            )
            for fact in facts
        ]