// 班级 API 处理器 — 创建班级、加入班级、查询班级

use axum::extract::{Extension, FromRef, Path, State};
use axum::http::StatusCode;
use axum::response::Json;
use uuid::Uuid;
use validator::Validate;

use erp_core::error::AppError;
use erp_core::rbac::require_permission;
use erp_core::types::{ApiResponse, TenantContext};

use crate::dto::{ClassMemberResp, ClassResp, CreateClassReq, JoinClassReq, ResetClassCodeResp, UpdateClassReq};
use crate::service::class_service::ClassService;
use crate::state::DiaryState;

#[utoipa::path(
    post,
    path = "/api/v1/diary/classes",
    request_body = CreateClassReq,
    responses(
        (status = 201, description = "创建成功", body = ApiResponse<ClassResp>),
        (status = 400, description = "验证失败"),
        (status = 401, description = "未授权"),
        (status = 403, description = "权限不足"),
    ),
    security(("bearer_auth" = [])),
    tag = "班级管理"
)]
/// POST /api/v1/diary/classes
///
/// 创建班级。需要 `diary.class.manage` 权限（老师角色）。
pub async fn create_class<S>(
    State(state): State<DiaryState>,
    Extension(ctx): Extension<TenantContext>,
    Json(req): Json<CreateClassReq>,
) -> Result<(StatusCode, Json<ApiResponse<ClassResp>>), AppError>
where
    DiaryState: FromRef<S>,
    S: Clone + Send + Sync + 'static,
{
    req.validate().map_err(|e| AppError::Validation(e.to_string()))?;
    require_permission(&ctx, "diary.class.manage")?;

    if req.name.trim().is_empty() {
        return Err(AppError::Validation("班级名称不能为空".to_string()));
    }

    let resp = ClassService::create_class(
        ctx.tenant_id,
        ctx.user_id,
        req.name,
        req.school_name,
        &state.db,
        &state.event_bus,
    )
    .await?;

    Ok((StatusCode::CREATED, Json(ApiResponse::ok(resp))))
}

#[utoipa::path(
    post,
    path = "/api/v1/diary/classes/join",
    request_body = JoinClassReq,
    responses(
        (status = 201, description = "加入成功", body = ApiResponse<ClassResp>),
        (status = 400, description = "班级码无效或已过期"),
        (status = 401, description = "未授权"),
        (status = 403, description = "权限不足"),
    ),
    security(("bearer_auth" = [])),
    tag = "班级管理"
)]
/// POST /api/v1/diary/classes/join
///
/// 通过班级码加入班级。需要 `diary.journal.create` 权限（学生使用此权限加入）。
pub async fn join_class<S>(
    State(state): State<DiaryState>,
    Extension(ctx): Extension<TenantContext>,
    Json(req): Json<JoinClassReq>,
) -> Result<(StatusCode, Json<ApiResponse<ClassResp>>), AppError>
where
    DiaryState: FromRef<S>,
    S: Clone + Send + Sync + 'static,
{
    req.validate().map_err(|e| AppError::Validation(e.to_string()))?;
    req.validate_code().map_err(AppError::Validation)?;
    require_permission(&ctx, "diary.journal.create")?;

    if req.class_code.trim().is_empty() {
        return Err(AppError::Validation("班级码不能为空".to_string()));
    }

    let resp = ClassService::join_class(
        ctx.tenant_id,
        ctx.user_id,
        req.class_code,
        None, // 昵称暂不通过此接口传递
        &state.db,
        state.redis.as_ref(),
        &state.event_bus,
    )
    .await?;

    Ok((StatusCode::CREATED, Json(ApiResponse::ok(resp))))
}

#[utoipa::path(
    get,
    path = "/api/v1/diary/classes/{id}",
    params(("id" = Uuid, Path, description = "班级ID")),
    responses(
        (status = 200, description = "成功", body = ApiResponse<ClassResp>),
        (status = 401, description = "未授权"),
        (status = 403, description = "权限不足"),
        (status = 404, description = "班级不存在"),
    ),
    security(("bearer_auth" = [])),
    tag = "班级管理"
)]
/// GET /api/v1/diary/classes/:id
///
/// 获取班级详情。需要 `diary.journal.read` 权限。
pub async fn get_class<S>(
    State(state): State<DiaryState>,
    Extension(ctx): Extension<TenantContext>,
    Path(id): Path<Uuid>,
) -> Result<Json<ApiResponse<ClassResp>>, AppError>
where
    DiaryState: FromRef<S>,
    S: Clone + Send + Sync + 'static,
{
    require_permission(&ctx, "diary.journal.read")?;

    let resp = ClassService::get_class(ctx.tenant_id, id, &state.db).await?;
    Ok(Json(ApiResponse::ok(resp)))
}

#[utoipa::path(
    get,
    path = "/api/v1/diary/classes/{id}/members",
    params(("id" = Uuid, Path, description = "班级ID")),
    responses(
        (status = 200, description = "成功", body = ApiResponse<Vec<ClassMemberResp>>),
        (status = 401, description = "未授权"),
        (status = 403, description = "权限不足"),
        (status = 404, description = "班级不存在"),
    ),
    security(("bearer_auth" = [])),
    tag = "班级管理"
)]
/// GET /api/v1/diary/classes/:id/members
///
/// 获取班级成员列表。需要 `diary.journal.read` 权限。
pub async fn list_members<S>(
    State(state): State<DiaryState>,
    Extension(ctx): Extension<TenantContext>,
    Path(id): Path<Uuid>,
) -> Result<Json<ApiResponse<Vec<ClassMemberResp>>>, AppError>
where
    DiaryState: FromRef<S>,
    S: Clone + Send + Sync + 'static,
{
    require_permission(&ctx, "diary.journal.read")?;

    let resp = ClassService::list_members(ctx.tenant_id, id, &state.db).await?;
    Ok(Json(ApiResponse::ok(resp)))
}

#[utoipa::path(
    get,
    path = "/api/v1/diary/classes/my",
    responses(
        (status = 200, description = "成功", body = ApiResponse<Vec<ClassResp>>),
        (status = 401, description = "未授权"),
        (status = 403, description = "权限不足"),
    ),
    security(("bearer_auth" = [])),
    tag = "班级管理"
)]
/// GET /api/v1/diary/classes/my
///
/// 获取当前用户加入的所有班级。需要 `diary.journal.read` 权限。
pub async fn my_classes<S>(
    State(state): State<DiaryState>,
    Extension(ctx): Extension<TenantContext>,
) -> Result<Json<ApiResponse<Vec<ClassResp>>>, AppError>
where
    DiaryState: FromRef<S>,
    S: Clone + Send + Sync + 'static,
{
    require_permission(&ctx, "diary.journal.read")?;

    let resp = ClassService::my_classes(ctx.tenant_id, ctx.user_id, &state.db).await?;
    Ok(Json(ApiResponse::ok(resp)))
}

#[utoipa::path(
    get,
    path = "/api/v1/diary/classes/all",
    responses(
        (status = 200, description = "成功", body = ApiResponse<Vec<ClassResp>>),
        (status = 401, description = "未授权"),
        (status = 403, description = "权限不足"),
    ),
    security(("bearer_auth" = [])),
    tag = "班级管理"
)]
/// GET /api/v1/diary/classes/all
///
/// 获取租户下所有班级（管理端用）。需要 `diary.class.manage` 权限。
pub async fn list_all_classes<S>(
    State(state): State<DiaryState>,
    Extension(ctx): Extension<TenantContext>,
) -> Result<Json<ApiResponse<Vec<ClassResp>>>, AppError>
where
    DiaryState: FromRef<S>,
    S: Clone + Send + Sync + 'static,
{
    require_permission(&ctx, "diary.class.manage")?;

    let resp = ClassService::list_all_classes(ctx.tenant_id, &state.db).await?;
    Ok(Json(ApiResponse::ok(resp)))
}

#[utoipa::path(
    put,
    path = "/api/v1/diary/classes/{id}",
    params(("id" = Uuid, Path, description = "班级ID")),
    request_body = UpdateClassReq,
    responses(
        (status = 200, description = "更新成功", body = ApiResponse<ClassResp>),
        (status = 400, description = "验证失败"),
        (status = 401, description = "未授权"),
        (status = 403, description = "权限不足"),
        (status = 404, description = "班级不存在"),
        (status = 409, description = "版本冲突"),
    ),
    security(("bearer_auth" = [])),
    tag = "班级管理"
)]
/// PUT /api/v1/diary/classes/:id
///
/// 更新班级信息。需要 `diary.class.manage` 权限（仅班级创建者可编辑）。
pub async fn update_class<S>(
    State(state): State<DiaryState>,
    Extension(ctx): Extension<TenantContext>,
    Path(id): Path<Uuid>,
    Json(req): Json<UpdateClassReq>,
) -> Result<Json<ApiResponse<ClassResp>>, AppError>
where
    DiaryState: FromRef<S>,
    S: Clone + Send + Sync + 'static,
{
    req.validate().map_err(|e| AppError::Validation(e.to_string()))?;
    require_permission(&ctx, "diary.class.manage")?;

    if let Some(ref name) = req.name {
        if name.trim().is_empty() {
            return Err(AppError::Validation("班级名称不能为空".to_string()));
        }
    }

    let resp = ClassService::update_class(
        ctx.tenant_id,
        ctx.user_id,
        id,
        req.name,
        req.school_name,
        req.version,
        &state.db,
    )
    .await?;

    Ok(Json(ApiResponse::ok(resp)))
}

#[utoipa::path(
    patch,
    path = "/api/v1/diary/classes/{id}/deactivate",
    params(("id" = Uuid, Path, description = "班级ID")),
    responses(
        (status = 200, description = "停用成功", body = ApiResponse<ClassResp>),
        (status = 401, description = "未授权"),
        (status = 403, description = "权限不足"),
        (status = 404, description = "班级不存在"),
    ),
    security(("bearer_auth" = [])),
    tag = "班级管理"
)]
/// PATCH /api/v1/diary/classes/:id/deactivate
///
/// 停用班级。需要 `diary.class.manage` 权限（仅班级创建者可停用）。
pub async fn deactivate_class<S>(
    State(state): State<DiaryState>,
    Extension(ctx): Extension<TenantContext>,
    Path(id): Path<Uuid>,
) -> Result<Json<ApiResponse<ClassResp>>, AppError>
where
    DiaryState: FromRef<S>,
    S: Clone + Send + Sync + 'static,
{
    require_permission(&ctx, "diary.class.manage")?;

    let resp = ClassService::deactivate_class(
        ctx.tenant_id,
        ctx.user_id,
        id,
        &state.db,
        &state.event_bus,
    )
    .await?;

    Ok(Json(ApiResponse::ok(resp)))
}

#[utoipa::path(
    post,
    path = "/api/v1/diary/classes/{id}/reset-code",
    params(("id" = Uuid, Path, description = "班级ID")),
    responses(
        (status = 200, description = "重置成功", body = ApiResponse<ResetClassCodeResp>),
        (status = 401, description = "未授权"),
        (status = 403, description = "权限不足"),
        (status = 404, description = "班级不存在"),
    ),
    security(("bearer_auth" = [])),
    tag = "班级管理"
)]
/// POST /api/v1/diary/classes/:id/reset-code
///
/// 重置班级码。需要 `diary.class.manage` 权限（仅班级创建者可重置）。
pub async fn reset_class_code<S>(
    State(state): State<DiaryState>,
    Extension(ctx): Extension<TenantContext>,
    Path(id): Path<Uuid>,
) -> Result<Json<ApiResponse<ResetClassCodeResp>>, AppError>
where
    DiaryState: FromRef<S>,
    S: Clone + Send + Sync + 'static,
{
    require_permission(&ctx, "diary.class.manage")?;

    let resp = ClassService::reset_class_code(ctx.tenant_id, ctx.user_id, id, &state.db).await?;
    Ok(Json(ApiResponse::ok(resp)))
}