"""
defect_api.py — IOM Lager 7: FastAPI endpoints för felkoder

REST API för:
- Lista och söka felkoder
- Klassificera observationer
- Validera koder
"""

from __future__ import annotations

from typing import Dict, List, Optional

from fastapi import FastAPI, HTTPException, Query
from pydantic import BaseModel, Field

from defect_codes import REGISTRY, DefectCode
from defect_classifier import CLASSIFIER, ClassificationResult

app = FastAPI(
    title="IOM Lager 7 — Felklassificering",
    description="Hierarkiskt felkodsregister med AI-klassificering",
    version="1.0.0",
)


# ──────────────────────────────────────────────
# Schemas
# ──────────────────────────────────────────────

class DefectCodeOut(BaseModel):
    code: str
    name: str
    level: int
    parent: Optional[str] = None
    severity_hint: Optional[int] = None

    class Config:
        from_attributes = True


class DefectHierarchyOut(BaseModel):
    code: str
    name: str
    severity_hint: Optional[int]
    children: Dict[str, Dict]


class ClassificationRequest(BaseModel):
    text: str = Field(..., min_length=1, description="Beskrivning av observation")
    lang: str = Field(default="sv", description="Språk för respons")
    top_k: int = Field(default=3, ge=1, le=10)
    min_confidence: float = Field(default=0.3, ge=0.0, le=1.0)


class ClassificationAlternative(BaseModel):
    code: str
    name: Optional[str]
    confidence: float


class ClassificationResponse(BaseModel):
    code: str
    name: Optional[str]
    confidence: float
    matched_keyword: str
    severity_hint: Optional[int]
    alternatives: List[ClassificationAlternative]


class ValidateRequest(BaseModel):
    code: str = Field(..., pattern=r"^\d{4}$")


class ValidateResponse(BaseModel):
    valid: bool
    code: str
    name: Optional[str]
    warning: Optional[str] = None


class BatchClassifyRequest(BaseModel):
    texts: List[str] = Field(..., min_length=1)
    lang: str = "sv"
    top_k: int = 3
    min_confidence: float = 0.3


# ──────────────────────────────────────────────
# Helpers
# ──────────────────────────────────────────────

def _to_defect_out(code: DefectCode, lang: str = "sv") -> DefectCodeOut:
    return DefectCodeOut(
        code=code.code,
        name=code.name(lang),
        level=code.level,
        parent=code.parent,
        severity_hint=code.severity_hint,
    )


# ──────────────────────────────────────────────
# Endpoints
# ──────────────────────────────────────────────

@app.get("/", tags=["meta"])
async def root() -> Dict:
    return {
        "service": "IOM Lager 7 — Felklassificering",
        "version": "1.0.0",
        "codes_total": len(REGISTRY.all_codes()),
        "categories": len(REGISTRY.categories()),
    }


@app.get("/codes", response_model=List[DefectCodeOut], tags=["koder"])
async def list_codes(
    lang: str = Query(default="sv", description="Språk för namn"),
    level: Optional[int] = Query(default=None, ge=1, le=2),
    parent: Optional[str] = Query(default=None, pattern=r"^\d{4}$"),
) -> List[DefectCodeOut]:
    """Lista alla felkoder, med filtrering på nivå eller förälder."""
    codes = REGISTRY.all_codes()
    if level is not None:
        codes = [c for c in codes if c.level == level]
    if parent is not None:
        codes = [c for c in codes if c.parent == parent]
    return [_to_defect_out(c, lang) for c in codes]


@app.get("/codes/hierarchy", response_model=Dict[str, DefectHierarchyOut], tags=["koder"])
async def get_hierarchy(lang: str = Query(default="sv")) -> Dict:
    """Hämta hierarkin av felkoder."""
    return REGISTRY.to_dict(lang)


@app.get("/codes/{code}", response_model=DefectCodeOut, tags=["koder"])
async def get_code(code: str, lang: str = Query(default="sv")) -> DefectCodeOut:
    """Hämta en specifik felkod."""
    defect = REGISTRY.get(code)
    if not defect:
        raise HTTPException(status_code=404, detail=f"Felkod {code} hittades inte")
    return _to_defect_out(defect, lang)


@app.get("/codes/{code}/children", response_model=List[DefectCodeOut], tags=["koder"])
async def get_children(code: str, lang: str = Query(default="sv")) -> List[DefectCodeOut]:
    """Hämta underkoder till en given kod."""
    if code not in REGISTRY:
        raise HTTPException(status_code=404, detail=f"Felkod {code} hittades inte")
    children = REGISTRY.children(code)
    return [_to_defect_out(c, lang) for c in children]


@app.get("/codes/search", response_model=List[DefectCodeOut], tags=["koder"])
async def search_codes(
    q: str = Query(..., min_length=1, description="Sökfras"),
    lang: str = Query(default="sv"),
) -> List[DefectCodeOut]:
    """Sök felkoder på namn."""
    results = REGISTRY.search(q, lang)
    return [_to_defect_out(c, lang) for c in results]


@app.get("/codes/severity/{severity}", response_model=List[DefectCodeOut], tags=["koder"])
async def by_severity(
    severity: int,
    lang: str = Query(default="sv"),
) -> List[DefectCodeOut]:
    """Hämta felkoder med en viss severity_hint."""
    if not 1 <= severity <= 5:
        raise HTTPException(status_code=400, detail="severity måste vara 1-5")
    results = REGISTRY.by_severity(severity)
    return [_to_defect_out(c, lang) for c in results]


# ── Klassificering ──────────────────────────

@app.post("/classify", response_model=ClassificationResponse, tags=["klassificering"])
async def classify(request: ClassificationRequest) -> ClassificationResponse:
    """Klassificera en textbeskrivning till felkod."""
    result = CLASSIFIER.classify(
        text=request.text,
        top_k=request.top_k,
        min_confidence=request.min_confidence,
    )
    if not result:
        raise HTTPException(
            status_code=404,
            detail="Ingen matchande felkod hittades för given beskrivning",
        )
    return ClassificationResponse(**result.to_dict(request.lang))


@app.post("/classify/batch", response_model=List[Optional[ClassificationResponse]], tags=["klassificering"])
async def classify_batch(request: BatchClassifyRequest) -> List:
    """Klassificera flera texter i en batch."""
    results = CLASSIFIER.classify_batch(
        texts=request.texts,
        top_k=request.top_k,
        min_confidence=request.min_confidence,
    )
    return [
        ClassificationResponse(**r.to_dict(request.lang)) if r else None
        for r in results
    ]


# ── Validering ──────────────────────────────

@app.post("/validate", response_model=ValidateResponse, tags=["validering"])
async def validate(request: ValidateRequest) -> ValidateResponse:
    """Validera att en felkod finns och är lämplig."""
    valid, warning = CLASSIFIER.validate_code(request.code)
    defect = REGISTRY.get(request.code)
    return ValidateResponse(
        valid=valid,
        code=request.code,
        name=defect.name("sv") if defect else None,
        warning=warning,
    )


# ── Health ──────────────────────────────────

@app.get("/health", tags=["meta"])
async def health() -> Dict:
    return {"status": "ok", "codes_loaded": len(REGISTRY.all_codes())}