use uuid::Uuid;

use crate::error::AppError;
use crate::models::common::Role;
use crate::models::workspaces::WorkspaceStats;
use crate::service::WorkspaceService;
use crate::session::Session;

impl WorkspaceService {
    pub async fn workspace_stats(
        &self,
        ctx: &Session,
        workspace_id: Uuid,
    ) -> Result<WorkspaceStats, AppError> {
        let user_uid = ctx.user().ok_or(AppError::Unauthorized)?;
        let ws = self.find_workspace_by_id(workspace_id).await?;
        self.ensure_workspace_readable(user_uid, &ws).await?;
        self.ensure_workspace_stats(workspace_id).await
    }

    pub async fn workspace_refresh_stats(
        &self,
        ctx: &Session,
        workspace_id: Uuid,
    ) -> Result<WorkspaceStats, AppError> {
        let user_uid = ctx.user().ok_or(AppError::Unauthorized)?;
        let ws = self.find_workspace_by_id(workspace_id).await?;
        self.ensure_workspace_role_at_least(user_uid, &ws, Role::Admin)
            .await?;

        let members_count = sqlx::query_scalar::<_, i64>(
            "SELECT COUNT(*) FROM workspace_member WHERE workspace_id = $1 AND status = 'active'",
        )
        .bind(workspace_id)
        .fetch_one(self.ctx.db.reader())
        .await
        .map_err(AppError::Database)?;

        let repos_count = sqlx::query_scalar::<_, i64>(
            "SELECT COUNT(*) FROM repo WHERE workspace_id = $1 AND deleted_at IS NULL",
        )
        .bind(workspace_id)
        .fetch_one(self.ctx.db.reader())
        .await
        .map_err(AppError::Database)?;

        let issues_count = sqlx::query_scalar::<_, i64>(
            "SELECT COUNT(*) FROM issue WHERE repo_id IN (SELECT id FROM repo WHERE workspace_id = $1 AND deleted_at IS NULL) AND deleted_at IS NULL",
        )
        .bind(workspace_id)
        .fetch_one(self.ctx.db.reader())
        .await
        .map_err(AppError::Database)?;

        let prs_count = sqlx::query_scalar::<_, i64>(
            "SELECT COUNT(*) FROM pull_request WHERE repo_id IN (SELECT id FROM repo WHERE workspace_id = $1 AND deleted_at IS NULL) AND deleted_at IS NULL",
        )
        .bind(workspace_id)
        .fetch_one(self.ctx.db.reader())
        .await
        .map_err(AppError::Database)?;

        let now = chrono::Utc::now();
        let result = sqlx::query_as::<_, WorkspaceStats>(
            "UPDATE workspace_stats SET members_count = $1, repos_count = $2, issues_count = $3, \
             pull_requests_count = $4, updated_at = $5 WHERE workspace_id = $6 \
             RETURNING workspace_id, members_count, repos_count, issues_count, pull_requests_count, \
             storage_bytes, bandwidth_bytes, build_minutes_used, last_activity_at, updated_at",
        )
        .bind(members_count)
        .bind(repos_count)
        .bind(issues_count)
        .bind(prs_count)
        .bind(now)
        .bind(workspace_id)
        .fetch_one(self.ctx.db.writer())
        .await
        .map_err(AppError::Database)?;

        Ok(result)
    }

    async fn ensure_workspace_stats(&self, workspace_id: Uuid) -> Result<WorkspaceStats, AppError> {
        if let Some(stats) = sqlx::query_as::<_, WorkspaceStats>(
            "SELECT workspace_id, members_count, repos_count, issues_count, pull_requests_count, \
             storage_bytes, bandwidth_bytes, build_minutes_used, last_activity_at, updated_at \
             FROM workspace_stats WHERE workspace_id = $1",
        )
        .bind(workspace_id)
        .fetch_optional(self.ctx.db.reader())
        .await
        .map_err(AppError::Database)?
        {
            return Ok(stats);
        }

        sqlx::query(
            "INSERT INTO workspace_stats (workspace_id, members_count, repos_count, issues_count, \
             pull_requests_count, storage_bytes, bandwidth_bytes, build_minutes_used, updated_at) \
             VALUES ($1, 0, 0, 0, 0, 0, 0, 0, $2) ON CONFLICT (workspace_id) DO NOTHING",
        )
        .bind(workspace_id)
        .bind(chrono::Utc::now())
        .execute(self.ctx.db.writer())
        .await
        .map_err(AppError::Database)?;
        sqlx::query_as::<_, WorkspaceStats>(
            "SELECT workspace_id, members_count, repos_count, issues_count, pull_requests_count, \
             storage_bytes, bandwidth_bytes, build_minutes_used, last_activity_at, updated_at \
             FROM workspace_stats WHERE workspace_id = $1",
        )
        .bind(workspace_id)
        .fetch_one(self.ctx.db.reader())
        .await
        .map_err(AppError::Database)
    }
}