use uuid::Uuid;
use serde::Serialize;
use sqlx::{PgPool, postgres::PgQueryResult};
use crate::app_error::AppError;

#[derive(Serialize, sqlx::FromRow)]
pub struct Device {
    pub id: Uuid,
    pub home_id: Uuid,
    pub name: String,
    pub description: Option<String>,
    pub device_type: DeviceType
}

#[derive(Serialize, sqlx::Type)]
#[sqlx(type_name = "device_type", rename_all = "snake_case")]
pub enum DeviceType {
    OnOffSwitch
}

impl Device {
    pub fn new(
        home_id: Uuid,
        name: String,
        description: Option<String>,
        device_type: String
    ) -> Result<Self, AppError> {
        Ok(Self {
            id: Uuid::now_v7(),
            home_id: home_id,
            name: name,
            description: description,
            device_type: match device_type.as_str() {
                "on_off_switch" => DeviceType::OnOffSwitch,
                _ => {return Err(AppError::invalid_input("Invalid device type"))}
            }
        })
    }

    pub async fn insert(
        &self,
        db: &PgPool,
        user_id: Uuid,
        home_id: Uuid
    ) -> Result<(), AppError> {
        let result: PgQueryResult = sqlx::query!(
            "INSERT INTO devices (id, home_id, name, description, device_type)
            SELECT $1, $2, $3, $4, $5
            WHERE EXISTS (
                SELECT 1
                FROM users_homes
                WHERE user_id = $6
                    AND home_id = $2
                    AND is_admin = true
            )",
            self.id,
            home_id,
            self.name,
            self.description,
            &self.device_type as &DeviceType,
            user_id
        )
            .execute(db)
            .await?;

        if result.rows_affected() == 0 {
            return Err(AppError::forbidden("Unauthorized access to home"));
        }

        Ok(())
    }

    pub async fn delete(
        db: &PgPool,
        user_id: Uuid,
        home_id: Uuid,
        device_id: Uuid
    ) -> Result<(), AppError> {
        let result = sqlx::query!(
            "DELETE FROM devices
            WHERE id = $1
                AND home_id = $2
                AND EXISTS (
                    SELECT 1
                    FROM users_homes
                    WHERE user_id = $3
                        AND home_id = $2
                        AND is_admin = true
                );",
            device_id,
            home_id,
            user_id
        )
            .execute(db)
            .await?;

        if result.rows_affected() == 0 {
            return Err(AppError::forbidden("Unauthorized access to device"));
        }

        Ok(())
    }

    pub async fn find_one(
        db: &PgPool,
        user_id: Uuid,
        home_id: Uuid,
        device_id: Uuid,
    ) -> Result<Device, AppError> {
        let device = sqlx::query_as::<_, Device>(
            "SELECT devices.*
            FROM devices
            JOIN users_homes ON users_homes.home_id = devices.home_id
            WHERE devices.id = $1
                AND devices.home_id = $2
                AND users_homes.user_id = $3"
        )
            .bind(device_id)
            .bind(home_id)
            .bind(user_id)
            .fetch_optional(db)
            .await?;

        match device {
            Some(d) => Ok(d),
            None => Err(AppError::forbidden("Unauthorized access to device"))
        }
    }
}