from pydantic import BaseModel, Field
from typing import Optional


# ──────────────────────────────────────────────
# Core review models
# ──────────────────────────────────────────────

class Review(BaseModel):
    """A single review of a movie, book, or television show."""

    date: str = Field(
        ...,
        description="Date the review was recorded, in YYYY-MM-DD format.",
        examples=["2025-02-06"],
    )
    unixTime: int = Field(
        ...,
        description="Unix timestamp corresponding to the review date.",
        examples=[1738796400],
    )
    category: Optional[str] = Field(
        None,
        description="Media type: Movies, Books, or Television.",
        examples=["Movies"],
    )
    title: Optional[str] = Field(
        None,
        description="Title of the work being reviewed.",
        examples=["The Brutalist"],
    )
    creator: Optional[str] = Field(
        None,
        description="Director, author, or showrunner of the work.",
        examples=["Brady Corbet"],
    )
    genre: Optional[str] = Field(
        None,
        description="Genre classification of the work.",
        examples=["Drama"],
    )
    rating: Optional[float] = Field(
        None,
        description="Rating on a scale from -3.0 (worst) to 3.0 (best). A rating of 0.0 indicates a neutral opinion (it was meh).",
        examples=[3.0],
    )
    review: Optional[str] = Field(
        None,
        description="Free-text review. Empty string or '.' indicates no written review.",
        examples=[
            "A wonderfully expansive film about the immigrant experience."
        ],
    )

    year: Optional[int] = Field(
        None,
        description="Release or publication year of the work.",
        examples=[2024],
    )

    model_config = {"from_attributes": True}


class ReviewListResponse(BaseModel):
    """Paginated response wrapper for a list of reviews."""

    total: int = Field(
        ...,
        description="Total number of reviews matching the query filters.",
        examples=[642],
    )
    limit: int = Field(
        ...,
        description="Maximum number of reviews returned in this response.",
        examples=[20],
    )
    offset: int = Field(
        ...,
        description="Number of reviews skipped from the start of the result set.",
        examples=[0],
    )
    results: list[Review] = Field(
        ...,
        description="The reviews for the current page.",
    )


# ──────────────────────────────────────────────
# Discovery models
# ──────────────────────────────────────────────

class CategoryCount(BaseModel):
    """A category with its review count."""

    category: str = Field(..., description="The media category name.", examples=["Movies"])
    count: int = Field(..., description="Number of reviews in this category.", examples=[412])


class GenreCount(BaseModel):
    """A genre with its review count."""

    genre: str = Field(..., description="The genre name.", examples=["Science Fiction"])
    count: int = Field(..., description="Number of reviews in this genre.", examples=[58])


class CreatorCount(BaseModel):
    """A creator with their review count."""

    creator: str = Field(..., description="Name of the director, author, or showrunner.", examples=["Steven Spielberg"])
    count: int = Field(..., description="Number of works by this creator that have been reviewed.", examples=[7])


# ──────────────────────────────────────────────
# Stats models
# ──────────────────────────────────────────────

class CategoryBreakdown(BaseModel):
    """Review count for a single category."""

    category: str = Field(..., examples=["Movies"])
    count: int = Field(..., examples=[412])


class OverviewStats(BaseModel):
    """High-level statistics across all reviews."""

    total_reviews: int = Field(..., description="Total number of reviews in the database.", examples=[642])
    categories: list[CategoryBreakdown] = Field(..., description="Number of reviews per category.")
    average_rating: float = Field(..., description="Mean rating across all reviews.", examples=[1.02])
    earliest_review: str = Field(..., description="Date of the oldest review.", examples=["2001-06-29"])
    latest_review: str = Field(..., description="Date of the most recent review.", examples=["2025-02-09"])


class CreatorStats(BaseModel):
    """A creator ranked by number of reviewed works."""

    creator: str = Field(..., description="Name of the creator.", examples=["Steven Spielberg"])
    review_count: int = Field(..., description="Number of reviewed works by this creator.", examples=[7])
    average_rating: float = Field(..., description="Mean rating across this creator's reviewed works.", examples=[1.57])


class GenreStats(BaseModel):
    """A genre with aggregated review statistics."""

    genre: str = Field(..., description="The genre name.", examples=["Science Fiction"])
    review_count: int = Field(..., description="Number of reviews in this genre.", examples=[58])
    average_rating: float = Field(..., description="Mean rating for reviews in this genre.", examples=[1.24])


class YearActivity(BaseModel):
    """Review activity for a single year."""

    year: str = Field(..., description="The four-digit year.", examples=["2025"])
    review_count: int = Field(..., description="Number of reviews recorded in this year.", examples=[3])
    average_rating: float = Field(..., description="Mean rating for reviews in this year.", examples=[1.67])


class DecadeStats(BaseModel):
    """Review activity grouped by the decade the work was released."""

    decade: str = Field(
        ...,
        description="The decade label (e.g. '1990s').",
        examples=["1990s"],
    )
    review_count: int = Field(
        ...,
        description="Number of reviewed works released in this decade.",
        examples=[45],
    )
    average_rating: float = Field(
        ...,
        description="Mean rating for works released in this decade.",
        examples=[1.35],
    )