use axum::extract::State;
use export::rest::AppResponseData;
use serde::{Deserialize, Serialize};
use utoipa::ToSchema;

use crate::errors::ApiError;
use crate::service::GitService;

#[derive(Debug, Clone, Serialize, Deserialize, ToSchema)]
pub struct LanguageOptionDto {
    /// BCP-47 代码（小写、`-` 分隔），如 `zh-cn`、`en`、`ja`。
    pub code: String,
    /// 本语名称，如「简体中文」。
    pub native_name: String,
    /// 英文名称，如 "Simplified Chinese"。
    pub english_name: String,
    /// 是否为「沿用内容语言」模式。
    pub auto: bool,
    /// 是否为部署时的缺省语言。
    pub default: bool,
}

#[utoipa::path(
    get,
    path = "/ai/languages",
    tag = "ai",
    description = "AI 输出语言清单；前端据此渲染语言选择器。`auto` 表示沿用代码注释的语言。",
    responses(
        (status = 200, description = "supported languages", body = AppResponseData<Vec<LanguageOptionDto>>)
    )
)]
pub async fn list_ai_languages(
    State(service): State<GitService>,
) -> Result<AppResponseData<Vec<LanguageOptionDto>>, ApiError> {
    let configured = ci_protocol::ai_languages::normalize(&service.state.config.ai.output_language);
    let options = ci_protocol::ai_languages::supported_codes()
        .into_iter()
        .map(|code| {
            let auto = ci_protocol::ai_languages::is_auto(code);
            let (native, english) = if auto {
                ("沿用内容语言".to_string(), "Match content".to_string())
            } else {
                let display = ci_protocol::ai_languages::display_name(code);
                // display_name 形如「简体中文 (Simplified Chinese)」；拆回两段。
                match display.split_once(" (") {
                    Some((native, english)) => (
                        native.to_string(),
                        english.trim_end_matches(')').to_string(),
                    ),
                    None => (display.clone(), display),
                }
            };
            LanguageOptionDto {
                code: code.to_string(),
                native_name: native,
                english_name: english,
                auto,
                default: code == configured,
            }
        })
        .collect();
    Ok(AppResponseData::ok(options))
}