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

use crate::api::response::{ApiErrorResponse, ApiResponse};
use crate::error::AppError;
use crate::models::base_info::{self, UserBaseInfo};
use crate::models::prs::PullRequestDetail;
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,
    /// PR number (unique within the repository)
    pub number: i64,
}

/// Get a pull request by number
///
/// Returns detailed information about a specific pull request.
/// Requires read access to the repository.
#[utoipa::path(
    get,
    path = "/api/v1/workspaces/{workspace_name}/repos/{repo_name}/prs/{number}",
    tag = "Pull Requests",
    operation_id = "prGet",
    params(PathParams),
    responses(
        (status = 200, description = "PR retrieved successfully. Returns complete PR with all metadata.", body = ApiResponse<PullRequestDetail>),
        (status = 401, description = "Authentication required or session expired", body = ApiErrorResponse),
        (status = 403, description = "Insufficient permissions to access this repository", body = ApiErrorResponse),
        (status = 404, description = "Repository, workspace, or PR not found", body = ApiErrorResponse),
        (status = 500, description = "Internal server error", body = ApiErrorResponse),
    ),
    security(
        ("session_cookie" = [])
    )
)]
pub async fn get(
    service: web::Data<AppService>,
    session: Session,
    path: web::Path<PathParams>,
) -> Result<HttpResponse, AppError> {
    let pr = service
        .pr
        .pr_get(&session, &path.workspace_name, &path.repo_name, path.number)
        .await?;
    let author_id = pr.author_id;
    let users = base_info::resolve_users(&service.ctx.db, &[author_id]).await?;
    let author = users
        .get(&author_id)
        .cloned()
        .unwrap_or_else(|| UserBaseInfo::placeholder(author_id));
    Ok(HttpResponse::Ok().json(ApiResponse::new(pr.into_detail(author))))
}