//! LLMクライアント + Timeline統合サンプル
//!
//! Anthropic Claude APIにリクエストを送信し、Timelineでイベントを処理するサンプル
//!
//! ## 使用方法
//!
//! ```bash
//! # .envファイルにAPIキーを設定
//! echo "ANTHROPIC_API_KEY=your-api-key" > .env
//!
//! # 実行
//! cargo run --example llm_client_anthropic
//! ```

use std::sync::{Arc, Mutex};

use futures::StreamExt;
use worker::{
    Handler, TextBlockEvent, TextBlockKind, Timeline, ToolUseBlockEvent, ToolUseBlockKind,
    UsageEvent, UsageKind,
    llm_client::{LlmClient, Request, providers::anthropic::AnthropicClient},
};

/// テキスト出力をリアルタイムで表示するハンドラー
struct PrintHandler;

impl Handler<TextBlockKind> for PrintHandler {
    type Scope = ();

    fn on_event(&mut self, _scope: &mut (), event: &TextBlockEvent) {
        match event {
            TextBlockEvent::Start(_) => {
                print!("\n🤖 Assistant: ");
            }
            TextBlockEvent::Delta(text) => {
                print!("{}", text);
                // 即時出力をフラッシュ
                use std::io::Write;
                std::io::stdout().flush().ok();
            }
            TextBlockEvent::Stop(_) => {
                println!("\n");
            }
        }
    }
}

/// テキストを蓄積するハンドラー
struct TextCollector {
    texts: Arc<Mutex<Vec<String>>>,
}

impl Handler<TextBlockKind> for TextCollector {
    type Scope = String;

    fn on_event(&mut self, buffer: &mut String, event: &TextBlockEvent) {
        match event {
            TextBlockEvent::Start(_) => {}
            TextBlockEvent::Delta(text) => {
                buffer.push_str(text);
            }
            TextBlockEvent::Stop(_) => {
                let text = std::mem::take(buffer);
                self.texts.lock().unwrap().push(text);
            }
        }
    }
}

/// ツール使用を検出するハンドラー
struct ToolUseDetector;

impl Handler<ToolUseBlockKind> for ToolUseDetector {
    type Scope = String; // JSON accumulator

    fn on_event(&mut self, json_buffer: &mut String, event: &ToolUseBlockEvent) {
        match event {
            ToolUseBlockEvent::Start(start) => {
                println!("\n🔧 Tool Call: {} (id: {})", start.name, start.id);
            }
            ToolUseBlockEvent::InputJsonDelta(json) => {
                json_buffer.push_str(json);
            }
            ToolUseBlockEvent::Stop(stop) => {
                println!("   Arguments: {}", json_buffer);
                println!("   Tool {} completed\n", stop.name);
            }
        }
    }
}

/// 使用量を追跡するハンドラー
struct UsageTracker {
    total_input: Arc<Mutex<u64>>,
    total_output: Arc<Mutex<u64>>,
}

impl Handler<UsageKind> for UsageTracker {
    type Scope = ();

    fn on_event(&mut self, _scope: &mut (), event: &UsageEvent) {
        if let Some(input) = event.input_tokens {
            *self.total_input.lock().unwrap() += input;
        }
        if let Some(output) = event.output_tokens {
            *self.total_output.lock().unwrap() += output;
        }
    }
}

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // APIキーを環境変数から取得
    let api_key = std::env::var("ANTHROPIC_API_KEY")
        .expect("ANTHROPIC_API_KEY environment variable must be set");

    println!("=== LLM Client + Timeline Integration Example ===\n");

    // クライアントを作成
    let client = AnthropicClient::new(api_key, "claude-sonnet-4-20250514");

    // 共有状態
    let collected_texts = Arc::new(Mutex::new(Vec::new()));
    let total_input = Arc::new(Mutex::new(0u64));
    let total_output = Arc::new(Mutex::new(0u64));

    // タイムラインを構築
    let mut timeline = Timeline::new();
    timeline
        .on_text_block(PrintHandler)
        .on_text_block(TextCollector {
            texts: collected_texts.clone(),
        })
        .on_tool_use_block(ToolUseDetector)
        .on_usage(UsageTracker {
            total_input: total_input.clone(),
            total_output: total_output.clone(),
        });

    // リクエストを作成
    let request = Request::new()
        .system("You are a helpful assistant. Be concise.")
        .user("What is the capital of Japan? Answer in one sentence.")
        .max_tokens(100);

    println!("📤 Sending request...\n");

    // ストリーミングリクエストを送信
    let mut stream = client.stream(request).await?;

    // イベントを処理
    while let Some(result) = stream.next().await {
        match result {
            Ok(event) => {
                timeline.dispatch(&event);
            }
            Err(e) => {
                eprintln!("Error: {}", e);
                break;
            }
        }
    }

    // 結果を表示
    println!("=== Summary ===");
    println!(
        "📊 Token Usage: {} input, {} output",
        total_input.lock().unwrap(),
        total_output.lock().unwrap()
    );

    let texts = collected_texts.lock().unwrap();
    println!("📝 Collected {} text block(s)", texts.len());

    Ok(())
}