use crate::error::AppError;
use crate::models::notifications::Notification;
use crate::service::NotificationService;
use crate::session::Session;
use chrono::Utc;
use uuid::Uuid;

use super::util::clamp_limit_offset;

impl NotificationService {
    pub async fn list_notifications(
        &self,
        session: &Session,
        unread_only: bool,
        limit: i64,
        offset: i64,
    ) -> Result<Vec<Notification>, AppError> {
        let user_id = session.user().ok_or(AppError::Unauthorized)?;
        let (limit, offset) = clamp_limit_offset(limit, offset);

        Notification::list_for_user(self.ctx.db.reader(), user_id, unread_only, limit, offset).await
    }

    pub async fn count_unread(&self, session: &Session) -> Result<i64, AppError> {
        let user_id = session.user().ok_or(AppError::Unauthorized)?;
        Notification::count_unread(self.ctx.db.reader(), user_id).await
    }

    pub async fn mark_as_read(
        &self,
        session: &Session,
        notification_id: Uuid,
    ) -> Result<Notification, AppError> {
        let user_id = session.user().ok_or(AppError::Unauthorized)?;
        let now = Utc::now();

        sqlx::query_as::<_, Notification>(
            "UPDATE notification SET read_at = $1, updated_at = $2 \
             WHERE id = $3 AND user_id = $4 AND deleted_at IS NULL \
             RETURNING id, user_id, notification_type, target_type, target_id, title, body, \
             action_url, action_text, read_at, dismissed_at, created_at, updated_at, deleted_at",
        )
        .bind(now)
        .bind(now)
        .bind(notification_id)
        .bind(user_id)
        .fetch_optional(self.ctx.db.writer())
        .await
        .map_err(AppError::Database)?
        .ok_or(AppError::NotFound("notification not found".into()))
    }

    pub async fn mark_all_as_read(&self, session: &Session) -> Result<i64, AppError> {
        let user_id = session.user().ok_or(AppError::Unauthorized)?;
        let now = Utc::now();

        let result = sqlx::query(
            "UPDATE notification SET read_at = $1, updated_at = $2 \
             WHERE user_id = $3 AND deleted_at IS NULL AND read_at IS NULL",
        )
        .bind(now)
        .bind(now)
        .bind(user_id)
        .execute(self.ctx.db.writer())
        .await
        .map_err(AppError::Database)?;

        Ok(result.rows_affected() as i64)
    }

    pub async fn dismiss_notification(
        &self,
        session: &Session,
        notification_id: Uuid,
    ) -> Result<Notification, AppError> {
        let user_id = session.user().ok_or(AppError::Unauthorized)?;
        let now = Utc::now();

        sqlx::query_as::<_, Notification>(
            "UPDATE notification SET dismissed_at = $1, updated_at = $2 \
             WHERE id = $3 AND user_id = $4 AND deleted_at IS NULL \
             RETURNING id, user_id, notification_type, target_type, target_id, title, body, \
             action_url, action_text, read_at, dismissed_at, created_at, updated_at, deleted_at",
        )
        .bind(now)
        .bind(now)
        .bind(notification_id)
        .bind(user_id)
        .fetch_optional(self.ctx.db.writer())
        .await
        .map_err(AppError::Database)?
        .ok_or(AppError::NotFound("notification not found".into()))
    }

    pub async fn delete_notification(
        &self,
        session: &Session,
        notification_id: Uuid,
    ) -> Result<(), AppError> {
        let user_id = session.user().ok_or(AppError::Unauthorized)?;
        let now = Utc::now();

        let result = sqlx::query(
            "UPDATE notification SET deleted_at = $1, updated_at = $2 \
             WHERE id = $3 AND user_id = $4 AND deleted_at IS NULL",
        )
        .bind(now)
        .bind(now)
        .bind(notification_id)
        .bind(user_id)
        .execute(self.ctx.db.writer())
        .await
        .map_err(AppError::Database)?;

        if result.rows_affected() == 0 {
            return Err(AppError::NotFound("notification not found".into()));
        }

        Ok(())
    }

    pub async fn clear_all_notifications(&self, session: &Session) -> Result<i64, AppError> {
        let user_id = session.user().ok_or(AppError::Unauthorized)?;
        let now = Utc::now();

        let result = sqlx::query(
            "UPDATE notification SET dismissed_at = $1, updated_at = $2 \
             WHERE user_id = $3 AND deleted_at IS NULL AND dismissed_at IS NULL",
        )
        .bind(now)
        .bind(now)
        .bind(user_id)
        .execute(self.ctx.db.writer())
        .await
        .map_err(AppError::Database)?;

        Ok(result.rows_affected() as i64)
    }
}