use crate::{
    errors::ApiError,
    extractors::{AuthUser, OptionalAuthUser},
    handlers::auth::to_user_response,
    state::AppState,
};
use api_types::{
    requests::{PaginationQuery, UpdateProfileRequest},
    responses::{ErrorResponse, UserResponse},
};
use application::use_cases::feed::list_users;
use application::use_cases::profile::{get_user_by_username, update_profile};
use application::use_cases::search::search_users;
use axum::{
    extract::{Path, Query, State},
    Json,
};

#[utoipa::path(
    get, path = "/users/{username}",
    params(("username" = String, Path, description = "Username")),
    responses(
        (status = 200, body = UserResponse),
        (status = 404, description = "User not found", body = ErrorResponse),
    )
)]
pub async fn get_user(
    State(s): State<AppState>,
    Path(username): Path<String>,
    OptionalAuthUser(viewer): OptionalAuthUser,
) -> Result<Json<UserResponse>, ApiError> {
    let user = get_user_by_username(&*s.users, &username).await?;
    let is_followed = if let Some(viewer_id) = viewer {
        s.follows.find(&viewer_id, &user.id).await?.is_some()
    } else {
        false
    };
    let mut resp = to_user_response(&user);
    resp.is_followed_by_viewer = is_followed;
    Ok(Json(resp))
}

#[utoipa::path(
    patch, path = "/users/me",
    request_body = UpdateProfileRequest,
    responses(
        (status = 200, body = UserResponse),
        (status = 401, description = "Unauthorized", body = ErrorResponse),
    ),
    security(("bearer_auth" = []))
)]
pub async fn patch_profile(
    State(s): State<AppState>,
    AuthUser(uid): AuthUser,
    Json(body): Json<UpdateProfileRequest>,
) -> Result<Json<UserResponse>, ApiError> {
    update_profile(
        &*s.users,
        &uid,
        body.display_name,
        body.bio,
        body.avatar_url,
        body.header_url,
        body.custom_css,
    )
    .await?;
    let user = s
        .users
        .find_by_id(&uid)
        .await?
        .ok_or(domain::errors::DomainError::NotFound)?;
    Ok(Json(to_user_response(&user)))
}

#[utoipa::path(
    get, path = "/users/me",
    responses(
        (status = 200, body = UserResponse),
        (status = 401, description = "Unauthorized", body = ErrorResponse),
    ),
    security(("bearer_auth" = []))
)]
pub async fn get_me(
    State(s): State<AppState>,
    AuthUser(uid): AuthUser,
) -> Result<Json<UserResponse>, ApiError> {
    let user = s
        .users
        .find_by_id(&uid)
        .await?
        .ok_or(domain::errors::DomainError::NotFound)?;
    Ok(Json(to_user_response(&user)))
}

pub async fn get_me_following_list(
    State(s): State<AppState>,
    AuthUser(uid): AuthUser,
    Query(q): Query<PaginationQuery>,
) -> Result<Json<serde_json::Value>, ApiError> {
    use application::use_cases::feed::get_following;
    use domain::models::feed::PageParams;
    let page = PageParams {
        page: q.page(),
        per_page: q.per_page(),
    };
    let result = get_following(&*s.follows, &uid, page).await?;
    Ok(Json(serde_json::json!({
        "total": result.total,
        "items": result.items.iter().map(to_user_response).collect::<Vec<_>>(),
    })))
}

pub async fn get_users(
    State(s): State<AppState>,
    Query(params): Query<std::collections::HashMap<String, String>>,
) -> Result<Json<serde_json::Value>, ApiError> {
    use domain::models::feed::PageParams;
    let page = params
        .get("page")
        .and_then(|v| v.parse::<u64>().ok())
        .unwrap_or(1);
    let per_page = params
        .get("per_page")
        .and_then(|v| v.parse::<u64>().ok())
        .unwrap_or(20);
    let page_params = PageParams { page, per_page };

    if let Some(q) = params.get("q").filter(|q| !q.trim().is_empty()) {
        let result = search_users(&*s.search, q, page_params).await?;
        let users: Vec<_> = result
            .items
            .iter()
            .map(crate::handlers::auth::to_user_response)
            .collect();
        return Ok(Json(serde_json::json!({
            "items": users, "total": result.total, "page": result.page, "per_page": result.per_page
        })));
    }

    let all = list_users(&*s.users).await?;
    let total = all.len() as i64;
    let start = ((page - 1) * per_page) as usize;
    let items: Vec<_> = all
        .into_iter()
        .skip(start)
        .take(per_page as usize)
        .map(|u| {
            serde_json::json!({
                "id": u.id.as_uuid(),
                "username": u.username,
                "displayName": u.display_name,
                "avatarUrl": u.avatar_url,
                "bio": u.bio,
                "headerUrl": null,
                "customCss": null,
                "local": true,
                "isFollowedByViewer": false,
                "joinedAt": null,
            })
        })
        .collect();
    Ok(Json(serde_json::json!({
        "items": items, "total": total, "page": page, "per_page": per_page
    })))
}

pub async fn get_user_count(
    State(s): State<AppState>,
) -> Result<Json<serde_json::Value>, ApiError> {
    let count = s.users.count().await?;
    Ok(Json(serde_json::json!({ "count": count })))
}