from typing import Dict, List

from fastapi import APIRouter, Depends, HTTPException, status
from pydantic import BaseModel, Field, model_validator
from sqlalchemy.orm import Session

from routes.dependencies import get_db
from services.settings import (
    CSS_COLOR_DEFAULTS,
    get_css_color_settings,
    list_css_env_override_rows,
    read_css_color_env_overrides,
    update_css_color_settings,
    get_theme_settings,
    save_theme_settings,
)

router = APIRouter(prefix="/api/settings", tags=["Settings"])


class CSSSettingsPayload(BaseModel):
    variables: Dict[str, str] = Field(default_factory=dict)

    @model_validator(mode="after")
    def _validate_allowed_keys(self) -> "CSSSettingsPayload":
        invalid = set(self.variables.keys()) - set(CSS_COLOR_DEFAULTS.keys())
        if invalid:
            invalid_keys = ", ".join(sorted(invalid))
            raise ValueError(
                f"Unsupported CSS variables: {invalid_keys}."
                " Accepted keys align with the default theme variables."
            )
        return self


class EnvOverride(BaseModel):
    css_key: str
    env_var: str
    value: str


class CSSSettingsResponse(BaseModel):
    variables: Dict[str, str]
    env_overrides: Dict[str, str] = Field(default_factory=dict)
    env_sources: List[EnvOverride] = Field(default_factory=list)


@router.get("/css", response_model=CSSSettingsResponse)
def read_css_settings(db: Session = Depends(get_db)) -> CSSSettingsResponse:
    try:
        values = get_css_color_settings(db)
        env_overrides = read_css_color_env_overrides()
        env_sources = [
            EnvOverride(**row) for row in list_css_env_override_rows()
        ]
    except ValueError as exc:
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=str(exc),
        ) from exc
    return CSSSettingsResponse(
        variables=values,
        env_overrides=env_overrides,
        env_sources=env_sources,
    )


@router.put(
    "/css", response_model=CSSSettingsResponse, status_code=status.HTTP_200_OK
)
def update_css_settings(
    payload: CSSSettingsPayload, db: Session = Depends(get_db)
) -> CSSSettingsResponse:
    try:
        values = update_css_color_settings(db, payload.variables)
        env_overrides = read_css_color_env_overrides()
        env_sources = [
            EnvOverride(**row) for row in list_css_env_override_rows()
        ]
    except ValueError as exc:
        raise HTTPException(
            status_code=status.HTTP_422_UNPROCESSABLE_CONTENT,
            detail=str(exc),
        ) from exc
    return CSSSettingsResponse(
        variables=values,
        env_overrides=env_overrides,
        env_sources=env_sources,
    )


class ThemeSettings(BaseModel):
    theme_name: str
    primary_color: str
    secondary_color: str
    accent_color: str
    background_color: str
    text_color: str


@router.post("/theme")
async def update_theme(theme_data: ThemeSettings, db: Session = Depends(get_db)):
    data_dict = theme_data.model_dump()
    save_theme_settings(db, data_dict)
    return {"message": "Theme updated", "theme": data_dict}


@router.get("/theme")
async def get_theme(db: Session = Depends(get_db)):
    return get_theme_settings(db)