import sqlite3

from fastapi import APIRouter, Depends, Query

from app.database import get_db
from app.models import CategoryCount, CreatorCount, GenreCount

router = APIRouter(tags=["Discovery"])

@router.get(
    "/categories",
    response_model=list[CategoryCount],
    summary="List all categories",
    description="Returns every media category, along with a count of the number of reviews in that category."
)
def list_categories(db: sqlite3.Connection = Depends(get_db)):
    rows = db.execute(
        "SELECT category, COUNT(*) as count FROM reviews GROUP BY category ORDER BY count DESC"
    ).fetchall()
    return [dict(row) for row in rows]

@router.get(
    "/genres",
    response_model=list[GenreCount],
    summary="List all genres",
    description="Returns every genre with review counts. Optionally filter to genres within a specific category.",
)
def list_genres(
    category: str | None = Query(None, description="Only show genres in this category.", examples=["Movies"]),
    db: sqlite3.Connection = Depends(get_db),
):
    conditions = []
    params = []

    if category:
        conditions.append("category = ?")
        params.append(category)

    where = ""
    if conditions:
        where = "WHERE " + " AND ".join(conditions)

    rows = db.execute(
        f"SELECT genre, COUNT(*) as count FROM reviews {where} GROUP BY genre ORDER BY count DESC",
        params,
    ).fetchall()
    return [dict(row) for row in rows]


@router.get(
    "/creators",
    response_model=list[CreatorCount],
    summary="List all creators",
    description="Returns every writer, director, or creator; with the number of works by them that has been reviewed. "
    "Optionally filter by category.",
)
def list_creators(
    category: str | None = Query(None, description="Only show creators in this category.", examples=["Books"]),
    db: sqlite3.Connection = Depends(get_db),
):
    conditions = []
    params = []

    if category:
        conditions.append("category = ?")
        params.append(category)

    where = ""
    if conditions:
        where = "WHERE " + " AND ".join(conditions)

    rows = db.execute(
        f"SELECT creator, COUNT(*) as count FROM reviews {where} GROUP BY creator ORDER BY count DESC",
        params,
    ).fetchall()
    return [dict(row) for row in rows]