//! 系统提示模板的单元测试。
//! Unit tests for system prompt templates.

use focus_core::model::Usage;
use focus_harness::prompt::{
    days_to_ymd, default_context, ContextUsage, PromptContext, SystemPromptTemplate,
};
use std::path::PathBuf;

#[test]
fn days_to_ymd_known_dates() {
    // 1970-01-01 → 0。
    assert_eq!(days_to_ymd(0), (1970, 1, 1));
    // 2000-01-01。
    // 30 年 * 365.25 ≈ 10957 天。
    assert_eq!(days_to_ymd(10_957), (2000, 1, 1));
    // 2024-02-29（闰年）。
    // 2024-02-29 (leap year).
    let days = (2024 - 1970) * 365 + (2024 - 1969) / 4 + 59;
    assert_eq!(days_to_ymd(days), (2024, 2, 29));
}

#[test]
fn renders_default_template() {
    let tpl = SystemPromptTemplate::default();
    let mut ctx = default_context();
    ctx.context_usage = Some(ContextUsage {
        estimated_tokens: 12_345,
        context_window: 128_000,
        window_known: true,
    });
    ctx.last_usage = Some(Usage {
        input_tokens: 100,
        output_tokens: 50,
        cache_read_tokens: 5,
        cache_write_tokens: 0,
    });
    ctx.extra.push("remember: rust edition 2021".to_string());
    let out = tpl.render(&ctx);
    assert!(out.contains(&ctx.cwd.display().to_string()));
    assert!(
        out.contains("Context usage: 12,345 / 128,000 tokens (9.6%)."),
        "got: {}",
        out
    );
    assert!(out.contains("Last turn usage: input 100, output 50, cache-read 5, cache-write 0."));
    assert!(out.contains("remember: rust edition 2021"));
    assert!(out.contains(ctx.os));
}

#[test]
fn renders_unknown_window_note() {
    let tpl = SystemPromptTemplate::default();
    let mut ctx = default_context();
    ctx.context_usage = Some(ContextUsage {
        estimated_tokens: 50_000,
        context_window: 128_000,
        window_known: false,
    });
    let out = tpl.render(&ctx);
    assert!(
        out.contains("window unknown; assuming 128,000"),
        "got: {}",
        out
    );
}

#[test]
fn missing_fields_render_empty() {
    let tpl = SystemPromptTemplate::default();
    let ctx = PromptContext {
        cwd: PathBuf::from("/tmp"),
        os: "linux",
        date: "2025-01-01".into(),
        shell: "bash".into(),
        context_usage: None,
        last_usage: None,
        extra: Vec::new(),
    };
    let out = tpl.render(&ctx);
    assert!(!out.contains("{context_usage}"));
    assert!(!out.contains("{last_usage}"));
}