//! context_slot_demo —— 多上下文槽位管理示例。
//! Required features: cargo run --example context_slot_demo --features "agent"
//!
//! 场景：法律咨询入口 → 派生两个独立探索方向 → 切换 → 隔离验证 → 删除。
//!
//! 展示：
//! - 默认 slot 自动创建
//! - 多 slot 间的消息隔离
//! - 派生 slot 从父 slot 复制消息
//! - 删除非 default slot 后自动回退到 default
//!
//! 运行：`cargo run --example context_slot_demo`（离线，零配置）

use std::sync::Arc;

use agcore::agent::{Agent, AgentBuilder, AgentSession};
use agcore::llm::LlmProvider;
use agcore::llm::hooks::HookExecutor;
use agcore::llm::mock::MockProvider;
use agcore::llm::types::Usage;
use agcore::llm::types::message::{ContentBlock, Message};
use agcore::llm::types::response_v2::{MessageResponse, StopReason};
use agcore::tools::ToolRegistry;

struct LegalAdvisor;

impl Agent for LegalAdvisor {
    fn name(&self) -> &str {
        "legal-advisor"
    }
    fn system_prompt(&self) -> Option<&str> {
        Some("你是法律顾问。请用一句话回答用户问题。")
    }
}

/// 构造一个简单的 Assistant 响应（用于 MockProvider）。
fn assistant_resp(text: &str) -> MessageResponse {
    MessageResponse {
        id: String::new(),
        model: "mock".into(),
        message: Message::Assistant {
            content: vec![ContentBlock::Text { text: text.into() }],
        },
        usage: Usage::from_input_output(5, 5),
        stop_reason: StopReason::Stop,
        extra: Default::default(),
    }
}

#[tokio::main]
async fn main() {
    // 1. 构造 session（自动包含 default slot）
    let provider: Arc<dyn LlmProvider> = Arc::new(MockProvider::new(vec![
        assistant_resp("您好，我可以帮您处理法律问题。"),
        assistant_resp("管辖权问题：建议选择合同签订地法院。"),
        assistant_resp("条款修改：建议将上限调整为 80 万。"),
        assistant_resp("已回到主对话。"),
    ]));
    let bundle = Arc::new(
        AgentBuilder::new()
            .provider(provider)
            .tool_registry(Arc::new(ToolRegistry::new()))
            .hook_executor(Arc::new(HookExecutor::new()))
            .build()
            .unwrap(),
    );
    let mut session = AgentSession::new(Arc::new(LegalAdvisor), "legal-001", bundle);

    println!("=== 1. 默认 slot 自动创建 ===");
    assert_eq!(session.current_slot_id(), "default");
    let slots: Vec<_> = session.list_slots().collect();
    println!("初始 slots: {slots:?}");
    assert_eq!(slots.len(), 1);
    assert!(slots.contains(&&"default".to_string()));

    println!("\n=== 2. 在 default slot 中提交一轮 ===");
    let r1 = session.submit_turn("我需要法律援助").await.unwrap();
    println!("default slot response: {}", r1.text());

    println!("\n=== 3. 派生两个独立探索方向的 slot ===");
    session
        .derive_slot(
            "option_jurisdiction",
            "default",
            agcore::agent::DeriveStrategy::Full,
        )
        .await
        .unwrap();
    session
        .derive_slot(
            "option_amendment",
            "default",
            agcore::agent::DeriveStrategy::Full,
        )
        .await
        .unwrap();
    let slots: Vec<_> = session.list_slots().cloned().collect();
    println!("派生后 slots: {slots:?}");
    assert_eq!(slots.len(), 3);

    println!("\n=== 4. 切到 option_jurisdiction 并提交 ===");
    session.switch_slot("option_jurisdiction").await.unwrap();
    assert_eq!(session.current_slot_id(), "option_jurisdiction");
    let r2 = session.submit_turn("如果用户质疑管辖权？").await.unwrap();
    println!("option_jurisdiction response: {}", r2.text());

    println!("\n=== 5. 切到 option_amendment 并提交 ===");
    session.switch_slot("option_amendment").await.unwrap();
    let r3 = session.submit_turn("用户要求提高赔偿上限？").await.unwrap();
    println!("option_amendment response: {}", r3.text());

    println!("\n=== 6. 切回 default，验证消息隔离 ===");
    session.switch_slot("default").await.unwrap();
    let r4 = session.submit_turn("汇总一下我们的讨论").await.unwrap();
    println!("default response: {}", r4.text());
    // 验证 default slot 不包含 option_jurisdiction 的"管辖权"问题
    let (_, default_slot) = session.slots().find(|(id, _)| *id == "default").unwrap();
    let default_has_jurisdiction = default_slot
        .messages
        .iter()
        .any(|m| message_contains(m, "管辖权"));
    assert!(
        !default_has_jurisdiction,
        "default slot 不应包含 option_jurisdiction 的消息"
    );

    println!("\n=== 7. 删除 option_amendment，验证回退到 default ===");
    session.delete_slot("option_amendment").await.unwrap();
    let slots: Vec<_> = session.list_slots().cloned().collect();
    println!("删除后 slots: {slots:?}");
    assert!(!slots.contains(&"option_amendment".to_string()));
    assert_eq!(slots.len(), 2);

    println!("\n=== 8. 切到 option_jurisdiction 并删除，验证 current 回退 ===");
    session.switch_slot("option_jurisdiction").await.unwrap();
    session.delete_slot("option_jurisdiction").await.unwrap();
    assert_eq!(session.current_slot_id(), "default");
    let slots: Vec<_> = session.list_slots().cloned().collect();
    println!("删除后 slots: {slots:?}");
    assert_eq!(slots.len(), 1);
    assert_eq!(slots[0], "default");

    println!("\n=== 9. 验证 delete_slot 保护逻辑 ===");
    let err = session.delete_slot("default").await.unwrap_err();
    println!("删除 default 返回错误: {err}");
    assert!(matches!(err, agcore::agent::AgentError::Config(_)));

    println!("\n✓ context_slot_demo 完成");
}

/// 检查 Message 是否包含指定文本（提取第一个 Text block）。
fn message_contains(msg: &Message, needle: &str) -> bool {
    use agcore::llm::types::message::ContentBlock;
    let blocks = match msg {
        Message::System { content }
        | Message::User { content }
        | Message::Assistant { content } => content,
        Message::UserImage { .. } => return false,
        Message::ToolResult { content, .. } => content,
        _ => return false,
    };
    for block in blocks {
        if let ContentBlock::Text { text } = block
            && text.contains(needle)
        {
            return true;
        }
    }
    false
}