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::issues::IssueCommentDetail;
use crate::service::AppService;
use crate::session::Session;

#[derive(Debug, Deserialize, IntoParams)]
pub struct PathParams {
    pub workspace_name: String,
    pub number: i64,
}

#[derive(Debug, Deserialize, IntoParams)]
pub struct QueryParams {
    pub limit: Option<i64>,
    pub offset: Option<i64>,
}

/// List issue comments
///
/// Returns a paginated list of comments on an issue, sorted by creation date (oldest first).
/// Requires read access to the issue.
#[utoipa::path(
    get,
    path = "/api/v1/workspaces/{workspace_name}/issues/{number}/comments",
    tag = "Issues",
    operation_id = "issueListComments",
    params(PathParams, QueryParams),
    responses(
        (status = 200, description = "Comments listed successfully.", body = ApiResponse<Vec<IssueCommentDetail>>),
        (status = 401, description = "Authentication required or session expired", body = ApiErrorResponse),
        (status = 403, description = "Insufficient permissions to view this issue", body = ApiErrorResponse),
        (status = 404, description = "Workspace or issue not found", body = ApiErrorResponse),
        (status = 500, description = "Internal server error", body = ApiErrorResponse),
    ),
    security(("session_cookie" = []))
)]
pub async fn list_comments(
    service: web::Data<AppService>,
    session: Session,
    path: web::Path<PathParams>,
    query: web::Query<QueryParams>,
) -> Result<HttpResponse, AppError> {
    let comments = service
        .issue
        .issue_comments(
            &session,
            &path.workspace_name,
            path.number,
            query.limit.unwrap_or(50),
            query.offset.unwrap_or(0),
        )
        .await?;
    let user_ids: Vec<_> = comments.iter().map(|c| c.author_id).collect();
    let users = base_info::resolve_users(&service.ctx.db, &user_ids).await?;
    let details: Vec<IssueCommentDetail> = comments
        .into_iter()
        .map(|c| {
            let author = users
                .get(&c.author_id)
                .cloned()
                .unwrap_or_else(|| UserBaseInfo::placeholder(c.author_id));
            c.into_detail(author)
        })
        .collect();
    Ok(HttpResponse::Ok().json(ApiResponse::new(details)))
}