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::service::pr::core::PrListFilters;
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, IntoParams)]
pub struct QueryParams {
    /// Filter by PR state ("open", "closed", "merged")
    pub state: Option<String>,
    /// Filter by author user ID
    pub author_id: Option<uuid::Uuid>,
    /// Filter by draft status
    pub draft: Option<bool>,
    /// Maximum number of PRs to return (default: 50, max: 100)
    pub limit: Option<i64>,
    /// Number of PRs to skip for pagination (default: 0)
    pub offset: Option<i64>,
}

/// List pull requests in a repository
///
/// Returns a paginated list of pull requests, sorted by number (newest first).
/// Supports filtering by state, author, and draft status.
/// Requires read access to the repository.
#[utoipa::path(
    get,
    path = "/api/v1/workspaces/{workspace_name}/repos/{repo_name}/prs",
    tag = "Pull Requests",
    operation_id = "prList",
    params(PathParams, QueryParams),
    responses(
        (status = 200, description = "PRs listed successfully. Returns filtered array of PR objects.", body = ApiResponse<Vec<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 or workspace not found", body = ApiErrorResponse),
        (status = 500, description = "Internal server error", body = ApiErrorResponse),
    ),
    security(
        ("session_cookie" = [])
    )
)]
pub async fn list(
    service: web::Data<AppService>,
    session: Session,
    path: web::Path<PathParams>,
    query: web::Query<QueryParams>,
) -> Result<HttpResponse, AppError> {
    let filters = PrListFilters {
        state: query.state.clone(),
        author_id: query.author_id,
        draft: query.draft,
    };
    let prs = service
        .pr
        .pr_list(
            &session,
            &path.workspace_name,
            &path.repo_name,
            filters,
            query.limit.unwrap_or(50),
            query.offset.unwrap_or(0),
        )
        .await?;
    let user_ids: Vec<_> = prs.iter().map(|p| p.author_id).collect();
    let users = base_info::resolve_users(&service.ctx.db, &user_ids).await?;
    let details: Vec<PullRequestDetail> = prs
        .into_iter()
        .map(|p| {
            let author = users
                .get(&p.author_id)
                .cloned()
                .unwrap_or_else(|| UserBaseInfo::placeholder(p.author_id));
            p.into_detail(author)
        })
        .collect();
    Ok(HttpResponse::Ok().json(ApiResponse::new(details)))
}