"""Pydantic request/response models for the FastAPI layer."""
from __future__ import annotations

from typing import List, Optional

from pydantic import BaseModel, Field


# ---------------------------------------------------------------------------
# Shared
# ---------------------------------------------------------------------------

class ProductOut(BaseModel):
    image_id: str
    image_url: Optional[str] = None
    image_urls: List[str] = Field(default_factory=list)
    brand: str
    product_name: str
    title: Optional[str] = None
    category: Optional[str] = None
    description: Optional[str] = None
    price_range: Optional[str] = None
    size_variants: List[str] = Field(default_factory=list)
    providers: List[str] = Field(default_factory=list)
    highlights: List[str] = Field(default_factory=list)
    nutrients: List[str] = Field(default_factory=list)
    fssai_license: Optional[str] = None
    product_sku: Optional[str] = None
    sku_source: Optional[str] = None
    hsn_code: Optional[str] = None
    final_selling_price: Optional[float] = None
    selling_price: Optional[float] = None
    barcode: Optional[str] = None
    barcode_type: Optional[str] = None


class SourceProductOut(BaseModel):
    image_id: str
    image_url: Optional[str] = None
    image_urls: List[str] = Field(default_factory=list)
    brand: str
    product_name: str
    title: Optional[str] = None
    category: Optional[str] = None
    description: Optional[str] = None
    price_range: Optional[str] = None
    size_variants: List[str] = Field(default_factory=list)
    providers: List[str] = Field(default_factory=list)
    highlights: List[str] = Field(default_factory=list)
    nutrients: List[str] = Field(default_factory=list)
    fssai_license: Optional[str] = None
    product_sku: Optional[str] = None
    sku_source: Optional[str] = None
    hsn_code: Optional[str] = None
    final_selling_price: Optional[float] = None
    selling_price: Optional[float] = None
    barcode: Optional[str] = None
    barcode_type: Optional[str] = None
    similarity: float


# ---------------------------------------------------------------------------
# Health
# ---------------------------------------------------------------------------

class HealthOut(BaseModel):
    status: str
    database: bool
    ollama: bool
    ollama_model: str
    embeddings_model: str


# ---------------------------------------------------------------------------
# Brands / catalog browsing
# ---------------------------------------------------------------------------

class BrandsOut(BaseModel):
    brands: List[str]


class BrandCardOut(BaseModel):
    """A brand as shown on the home page card grid.

    `name` is the same string GET /api/brands returns, so the frontend can
    pass it straight back to /api/brands/{brand}/products.
    """
    name: str
    slug: str
    product_count: int
    category_count: int
    categories: List[str] = Field(default_factory=list)
    image_url: Optional[str] = None
    initials: str


class BrandCardsOut(BaseModel):
    total_brands: int
    total_products: int
    brands: List[BrandCardOut]


class CategoriesOut(BaseModel):
    brand: str
    categories: List[str]


class ProductListOut(BaseModel):
    brand: str
    total: int
    limit: int
    offset: int
    products: List[ProductOut]


class AllProductsOut(BaseModel):
    total: int
    limit: int
    offset: int
    products: List[ProductOut]


# ---------------------------------------------------------------------------
# Semantic search (retrieval only, no LLM generation)
# ---------------------------------------------------------------------------

class SearchOut(BaseModel):
    query: str
    # Echoes the *request* param, as it always has. The brand inferred from the
    # query text goes in `detected_brand` instead - repurposing this field would
    # break any consumer reading it as "the filter I sent".
    brand: Optional[str] = None
    results: List[SourceProductOut]
    # Exact in brand_catalog mode. None in hybrid mode: the merge happens in
    # Python across N brand tables after per-table LIMITs, so there is no cheap
    # exact count and inventing one would misreport how much was found.
    total: Optional[int] = None
    limit: int = 0
    offset: int = 0
    match_mode: str = "hybrid"          # "brand_catalog" | "hybrid"
    detected_brand: Optional[str] = None
    detected_category: Optional[str] = None


class SuggestionOut(BaseModel):
    """One row in the search box's autocomplete dropdown."""
    type: str                           # "brand" | "category"
    value: str                          # what the search box / filter should use
    label: str                          # display text
    sublabel: Optional[str] = None      # e.g. "128 products"
    score: float = 0.0


class SuggestOut(BaseModel):
    query: str
    suggestions: List[SuggestionOut]


# ---------------------------------------------------------------------------
# RAG chat
# ---------------------------------------------------------------------------

class ChatTurn(BaseModel):
    role: str = Field(..., description="'user' or 'assistant'")
    content: str


class ChatRequest(BaseModel):
    query: str = Field(..., min_length=1, max_length=2000)
    brand: Optional[str] = Field(None, description="Restrict retrieval to a single brand")
    category: Optional[str] = Field(None, description="Restrict retrieval to a category")
    top_k: Optional[int] = Field(None, ge=1, le=15)
    history: Optional[List[ChatTurn]] = Field(default=None, description="Prior turns for follow-up questions")


class ChatResponseOut(BaseModel):
    answer: str
    query: str
    brand: Optional[str] = None
    detected_category: Optional[str] = Field(
        None, description="Product category auto-detected from the query and used to scope retrieval, if any"
    )
    sources: List[SourceProductOut]


# ---------------------------------------------------------------------------
# Catalog generation (admin/ingestion trigger)
# ---------------------------------------------------------------------------

class CatalogGenerateRequest(BaseModel):
    brand: str = Field(..., min_length=1, max_length=120)
    max_products: int = Field(50, ge=1, le=300)


class CatalogJobOut(BaseModel):
    job_id: str
    brand: str
    status: str
    detail: Optional[str] = None