use actix_web::{HttpResponse, web};
use serde::Deserialize;
use utoipa::{IntoParams, ToSchema};

use crate::api::response::{ApiErrorResponse, ApiResponse};
use crate::error::AppError;
use crate::models::base_info::{resolve_users, resolve_workspaces};
use crate::models::repos::RepoDetail;
use crate::service::AppService;
use crate::session::Session;

#[derive(Debug, Deserialize, IntoParams)]
pub struct PathParams {
    /// Workspace name (unique identifier)
    pub workspace_name: String,
    /// Repository name (unique within the workspace)
    pub repo_name: String,
}

#[derive(Debug, Deserialize, ToSchema)]
pub struct TransferOwnerParams {
    /// User ID of the new owner (must be a repository member)
    pub new_owner_id: uuid::Uuid,
}

/// Transfer repository ownership
///
/// Transfers ownership of a repository to another user. The new owner must be an existing repository member.
/// Requires Owner role in the repository.
///
/// Effects:
/// - Current owner becomes an Admin
/// - New owner gains full Owner permissions
/// - Repository URL remains unchanged
/// - All forks and stars are preserved
///
/// Returns the updated repository with new owner information.
#[utoipa::path(
    post,
    path = "/api/v1/workspaces/{workspace_name}/repos/{repo_name}/transfer-owner",
    tag = "Repos",
    operation_id = "repoTransferOwner",
    params(PathParams),
    request_body(
        content = TransferOwnerParams,
        description = "Transfer ownership parameters",
        content_type = "application/json"
    ),
    responses(
        (status = 200, description = "Ownership transferred successfully. Returns the repository with updated owner information.", body = ApiResponse<RepoDetail>),
        (status = 400, description = "Invalid new owner ID or user is not a repository member", body = ApiErrorResponse),
        (status = 401, description = "Authentication required or session expired", body = ApiErrorResponse),
        (status = 403, description = "Insufficient permissions (requires Owner role)", body = ApiErrorResponse),
        (status = 404, description = "Repository, workspace, or new owner not found", body = ApiErrorResponse),
        (status = 500, description = "Internal server error", body = ApiErrorResponse),
    ),
    security(
        ("session_cookie" = [])
    )
)]
pub async fn transfer_owner(
    service: web::Data<AppService>,
    session: Session,
    path: web::Path<PathParams>,
    params: web::Json<TransferOwnerParams>,
) -> Result<HttpResponse, AppError> {
    let repo = service
        .repo
        .repo_transfer_owner(
            &session,
            &path.workspace_name,
            &path.repo_name,
            params.new_owner_id,
        )
        .await?;

    let db = &service.ctx.db;
    let users = resolve_users(db, &[repo.owner_id]).await?;
    let workspaces = resolve_workspaces(db, &[repo.workspace_id]).await?;
    let owner = users.get(&repo.owner_id).cloned().unwrap_or_default();
    let workspace = workspaces
        .get(&repo.workspace_id)
        .cloned()
        .unwrap_or_default();
    let detail = repo.into_detail(owner, workspace);

    Ok(HttpResponse::Ok().json(ApiResponse::new(detail)))
}