use serde::{Deserialize, Serialize};
use uuid::Uuid;

use crate::error::AppError;
use crate::models::common::{RequestType, Role, Status};
use crate::models::workspaces::WorkspacePendingApproval;
use crate::service::WorkspaceService;
use crate::session::Session;

use super::util::{clamp_limit_offset, ensure_affected, parse_enum};

#[derive(Deserialize, Serialize, Clone, Debug, utoipa::ToSchema)]
pub struct RequestApprovalParams {
    pub request_type: String,
    pub reason: Option<String>,
}

impl WorkspaceService {
    pub async fn workspace_pending_approvals(
        &self,
        ctx: &Session,
        workspace_id: Uuid,
        limit: i64,
        offset: i64,
    ) -> Result<Vec<WorkspacePendingApproval>, 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 (limit, offset) = clamp_limit_offset(limit, offset);
        sqlx::query_as::<_, WorkspacePendingApproval>(
            "SELECT id, workspace_id, requester_id, request_type, status, reason, \
             reviewed_by, reviewed_at, expires_at, created_at, updated_at \
             FROM workspace_pending_approval WHERE workspace_id = $1 ORDER BY created_at DESC LIMIT $2 OFFSET $3",
        )
        .bind(workspace_id)
        .bind(limit)
        .bind(offset)
        .fetch_all(self.ctx.db.reader())
        .await
        .map_err(AppError::Database)
    }

    pub async fn workspace_request_approval(
        &self,
        ctx: &Session,
        workspace_id: Uuid,
        params: RequestApprovalParams,
    ) -> Result<WorkspacePendingApproval, 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?;

        let request_type = parse_enum(
            Some(params.request_type),
            RequestType::Unknown,
            RequestType::Unknown,
            "request_type",
        )?;
        let now = chrono::Utc::now();

        let mut txn = self
            .ctx
            .db
            .writer()
            .begin()
            .await
            .map_err(|_| AppError::TxnError)?;
        sqlx::query("SET LOCAL app.current_user_id = $1")
            .bind(user_uid)
            .execute(&mut *txn)
            .await
            .map_err(AppError::Database)?;

        let result = sqlx::query_as::<_, WorkspacePendingApproval>(
            "INSERT INTO workspace_pending_approval (id, workspace_id, requester_id, request_type, status, \
             reason, expires_at, created_at, updated_at) VALUES ($1, $2, $3, $4, 'pending', $5, $6, $7, $7) \
             RETURNING id, workspace_id, requester_id, request_type, status, reason, \
             reviewed_by, reviewed_at, expires_at, created_at, updated_at",
        )
        .bind(Uuid::now_v7())
        .bind(workspace_id)
        .bind(user_uid)
        .bind(request_type)
        .bind(params.reason)
        .bind(now + chrono::Duration::days(30))
        .bind(now)
        .fetch_one(&mut *txn)
        .await
        .map_err(AppError::Database)?;

        txn.commit().await.map_err(|_| AppError::TxnError)?;
        Ok(result)
    }

    pub async fn workspace_review_approval(
        &self,
        ctx: &Session,
        workspace_id: Uuid,
        approval_id: Uuid,
        approved: bool,
    ) -> Result<(), 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::Owner)
            .await?;

        let status = if approved {
            Status::Accepted
        } else {
            Status::Rejected
        };
        let now = chrono::Utc::now();

        let mut txn = self
            .ctx
            .db
            .writer()
            .begin()
            .await
            .map_err(|_| AppError::TxnError)?;
        sqlx::query("SET LOCAL app.current_user_id = $1")
            .bind(user_uid)
            .execute(&mut *txn)
            .await
            .map_err(AppError::Database)?;

        let result = sqlx::query(
            "UPDATE workspace_pending_approval SET status = $1, reviewed_by = $2, reviewed_at = $3, updated_at = $3 \
             WHERE id = $4 AND workspace_id = $5 AND status = 'pending'",
        )
        .bind(status.to_string())
        .bind(user_uid)
        .bind(now)
        .bind(approval_id)
        .bind(workspace_id)
        .execute(&mut *txn)
        .await
        .map_err(AppError::Database)?;
        ensure_affected(
            result.rows_affected(),
            "approval not found or already reviewed",
        )?;

        txn.commit().await.map_err(|_| AppError::TxnError)?;
        Ok(())
    }
}