use std::fs;
use std::path::PathBuf;
use serde_json::Value;

fn read_json_lines(path: &str) -> Vec<Value> {
    let p = PathBuf::from(path);
    if !p.exists() {
        return vec![];
    }
    let content = fs::read_to_string(p).unwrap_or_default();
    content
        .lines()
        .filter_map(|l| serde_json::from_str::<Value>(l).ok())
        .collect()
}

fn summarize(items: Vec<Value>) -> (usize, usize, f64, Vec<(String, f64)>) {
    let mut total = 0usize;
    let mut failed = 0usize;
    let mut duration = 0f64;
    let mut tests = Vec::new();
    for v in items {
        let t = v.get("type").and_then(|x| x.as_str()).unwrap_or("");
        if t == "test" {
            let name = v.get("name").and_then(|x| x.as_str()).unwrap_or("").to_string();
            let event = v.get("event").and_then(|x| x.as_str()).unwrap_or("");
            let time = v.get("exec_time").and_then(|x| x.as_f64()).unwrap_or(0.0);
            total += 1;
            if event == "failed" {
                failed += 1;
            }
            duration += time;
            tests.push((name, time));
        }
    }
    tests.sort_by(|a, b| b.1.partial_cmp(&a.1).unwrap());
    (total, failed, duration, tests)
}

fn main() {
    let out_dir = PathBuf::from("target/test-reports");
    let _ = fs::create_dir_all(&out_dir);
    let default = read_json_lines("target/test-report-default.json");
    let js = read_json_lines("target/test-report-js.json");
    let (t1, f1, d1, s1) = summarize(default);
    let (t2, f2, d2, s2) = summarize(js);
    let mut md = String::new();
    md.push_str("# dsl-flow Test Report\n");
    md.push_str("\n");
    md.push_str("## Default features\n");
    md.push_str(&format!("- total: {}\n- failed: {}\n- duration: {:.3}s\n", t1, f1, d1));
    md.push_str("- top slow tests:\n");
    for (name, time) in s1.iter().take(5) {
        md.push_str(&format!("  - {}: {:.3}s\n", name, time));
    }
    md.push_str("\n");
    md.push_str("## JS feature\n");
    md.push_str(&format!("- total: {}\n- failed: {}\n- duration: {:.3}s\n", t2, f2, d2));
    md.push_str("- top slow tests:\n");
    for (name, time) in s2.iter().take(5) {
        md.push_str(&format!("  - {}: {:.3}s\n", name, time));
    }
    let out_path = out_dir.join("summary.md");
    let _ = fs::write(out_path, md);
    println!("report generated in target/test-reports/summary.md");
}