//! 后台任务的测试：运行、自动压缩、仅压缩（注入假 provider，零网络）。
//! Background-job tests: running, auto-compaction, compact-only (injected fake
//! provider, zero network).

mod fake;

use focus_core::model::*;
use focus_tui::config::TuiConfig;
use focus_tui::job::{JobEvent, RunJob};
use std::path::PathBuf;
use std::sync::mpsc::{channel, Receiver};

fn ready_config(window: Option<u64>) -> TuiConfig {
    TuiConfig {
        api_key: "sk-test".into(),
        model: "gpt-4o".into(),
        context_window: window,
        ..TuiConfig::default()
    }
}

/// 运行任务并收集事件，直到 Done。
/// Run the job and collect events until Done.
fn collect(job: RunJob) -> Vec<JobEvent> {
    let (tx, rx): (_, Receiver<JobEvent>) = channel();
    let handle = focus_tui::job::spawn(job, tx);
    let mut events = Vec::new();
    while let Ok(ev) = rx.recv() {
        let done = matches!(ev, JobEvent::Done { .. });
        events.push(ev);
        if done {
            break;
        }
    }
    let _ = handle.join();
    events
}

fn done_of(events: &[JobEvent]) -> (&Vec<Message>, &Vec<Message>, usize, Option<&str>) {
    match events.iter().rev().find_map(|e| match e {
        JobEvent::Done {
            messages,
            to_persist,
            appended_count,
            error,
        } => Some((messages, to_persist, *appended_count, error.as_deref())),
        _ => None,
    }) {
        Some(x) => x,
        None => panic!("no Done event"),
    }
}

fn long_transcript(n: usize) -> Vec<Message> {
    (0..n)
        .map(|i| Message::user_text(format!("msg {} {}", i, "x".repeat(200))))
        .collect()
}

#[test]
fn run_appends_user_and_assistant() {
    let job = RunJob {
        transcript: Vec::new(),
        user_text: Some("hi".into()),
        config: ready_config(None),
        cwd: PathBuf::from("."),
        system_prompt: "sys".into(),
        provider: Some(Box::new(fake::FakeProvider::new("agent reply", "SUMMARY"))),
    };
    let events = collect(job);
    let (messages, to_persist, appended, error) = done_of(&events);
    assert_eq!(error, None);
    assert_eq!(messages.len(), 2);
    assert!(matches!(&messages[0], Message::User(_)));
    let last = messages.last().unwrap();
    let text = match last {
        Message::Assistant(a) => a.content[0].as_text().map(|t| t.text.clone()),
        _ => None,
    };
    assert_eq!(text.as_deref(), Some("agent reply"));
    // 用户消息由任务统一追加并计入 to_persist。
    // The user message is appended by the job and counted in to_persist.
    assert_eq!(to_persist.len(), 2);
    assert_eq!(appended, 2);
    // 转发了 agent 事件。
    // Agent events were forwarded.
    assert!(events.iter().any(|e| matches!(e, JobEvent::Agent(_))));
}

#[test]
fn auto_compaction_then_run() {
    // 超过阈值（窗口 100，transcript 约 1000+ token）。
    // Over the threshold (window 100, transcript ~1000+ tokens).
    let transcript = long_transcript(10);
    let job = RunJob {
        transcript,
        user_text: Some("next".into()),
        config: ready_config(Some(100)),
        cwd: PathBuf::from("."),
        system_prompt: "sys".into(),
        provider: Some(Box::new(fake::FakeProvider::new(
            "agent reply",
            "SUMMARY TEXT",
        ))),
    };
    let events = collect(job);
    let (messages, to_persist, appended, error) = done_of(&events);
    assert_eq!(error, None);

    // 最终 transcript 以摘要 user 消息开头。
    // The final transcript starts with a summary user message.
    let first = &messages[0];
    let summary_text = match first {
        Message::User(u) => u.content[0].as_text().map(|t| t.text.clone()),
        _ => None,
    };
    assert!(
        summary_text
            .as_deref()
            .unwrap_or("")
            .contains("SUMMARY TEXT"),
        "expected summary in transcript head, got {:?}",
        summary_text
    );
    // 末尾是 user("next") + assistant("agent reply")。
    // The tail is user("next") + assistant("agent reply").
    let n = messages.len();
    assert!(matches!(&messages[n - 2], Message::User(_)));
    let last_text = match &messages[n - 1] {
        Message::Assistant(a) => a.content[0].as_text().map(|t| t.text.clone()),
        _ => None,
    };
    assert_eq!(last_text.as_deref(), Some("agent reply"));
    // to_persist = 摘要 + 本轮追加（user + assistant）。
    // to_persist = summary + this run's appended (user + assistant).
    assert_eq!(to_persist.len(), 3);
    assert_eq!(appended, 2);
    // 有压缩说明。
    // A compaction note was emitted.
    assert!(events
        .iter()
        .any(|e| matches!(e, JobEvent::Note(n) if n.contains("compacting"))));
}

#[test]
fn compact_only_produces_summary() {
    let transcript = long_transcript(10);
    let job = RunJob {
        transcript,
        user_text: None,
        config: ready_config(Some(100)),
        cwd: PathBuf::from("."),
        system_prompt: "sys".into(),
        provider: Some(Box::new(fake::FakeProvider::new(
            "agent reply",
            "SUMMARY TEXT",
        ))),
    };
    let events = collect(job);
    let (messages, to_persist, appended, error) = done_of(&events);
    assert_eq!(error, None);
    // 摘要消息出现在头部且要被持久化。
    // The summary message heads the transcript and is persisted.
    assert!(messages[0]
        .as_user_text()
        .map(|t| t.contains("SUMMARY TEXT"))
        .unwrap_or(false));
    assert_eq!(to_persist.len(), 1);
    assert_eq!(appended, 0);
}

#[test]
fn below_threshold_no_compaction() {
    // 窗口极大 → 不触发压缩。
    // Huge window → no compaction.
    let transcript = long_transcript(3);
    let job = RunJob {
        transcript,
        user_text: Some("hi".into()),
        config: ready_config(Some(1_000_000)),
        cwd: PathBuf::from("."),
        system_prompt: "sys".into(),
        provider: Some(Box::new(fake::FakeProvider::new("agent reply", "SUMMARY"))),
    };
    let events = collect(job);
    assert!(!events
        .iter()
        .any(|e| matches!(e, JobEvent::Note(n) if n.contains("compacting"))));
    let (messages, to_persist, appended, _) = done_of(&events);
    assert_eq!(messages.len(), 5); // 3 user + user("hi") + assistant
    assert_eq!(to_persist.len(), 2);
    assert_eq!(appended, 2);
}

/// 为 `Message` 提供便捷的文本访问（测试辅助）。
/// Convenience text accessor on `Message` (test helper).
trait AsUserText {
    fn as_user_text(&self) -> Option<String>;
}

impl AsUserText for Message {
    fn as_user_text(&self) -> Option<String> {
        match self {
            Message::User(u) => u.content[0].as_text().map(|t| t.text.clone()),
            _ => None,
        }
    }
}