use std::fs;
use std::io::{BufRead, BufReader, Write};
use std::os::unix::net::UnixStream;
use std::path::{Path, PathBuf};
use std::thread;
use std::time::{Duration, Instant, SystemTime, UNIX_EPOCH};

use portable_pty::{native_pty_system, Child, CommandBuilder, MasterPty, PtySize};

fn unique_test_dir() -> PathBuf {
    let nanos = SystemTime::now()
        .duration_since(UNIX_EPOCH)
        .map(|d| d.as_nanos())
        .unwrap_or(0);
    std::env::temp_dir().join(format!("herdr-api-test-{}-{nanos}", std::process::id()))
}

struct SpawnedHerdr {
    _master: Box<dyn MasterPty + Send>,
    child: Box<dyn Child + Send + Sync>,
}

fn wait_for_socket(path: &Path, timeout: Duration) {
    let deadline = Instant::now() + timeout;
    while Instant::now() < deadline {
        if path.exists() && UnixStream::connect(path).is_ok() {
            return;
        }
        thread::sleep(Duration::from_millis(25));
    }
    panic!("socket did not appear at {}", path.display());
}

fn spawn_herdr(config_home: &Path, runtime_dir: &Path, socket_path: &Path) -> SpawnedHerdr {
    fs::create_dir_all(config_home.join("herdr")).unwrap();
    fs::create_dir_all(runtime_dir).unwrap();
    fs::write(
        config_home.join("herdr/config.toml"),
        "onboarding = false\n",
    )
    .unwrap();

    let pair = native_pty_system()
        .openpty(PtySize {
            rows: 24,
            cols: 80,
            pixel_width: 0,
            pixel_height: 0,
        })
        .unwrap();

    let mut cmd = CommandBuilder::new(env!("CARGO_BIN_EXE_herdr"));
    cmd.arg("--no-session");
    cmd.env("XDG_CONFIG_HOME", config_home);
    cmd.env("XDG_RUNTIME_DIR", runtime_dir);
    cmd.env("HERDR_SOCKET_PATH", socket_path);

    let child = pair.slave.spawn_command(cmd).unwrap();

    SpawnedHerdr {
        _master: pair.master,
        child,
    }
}

fn send_request(socket_path: &Path, json: &str) -> serde_json::Value {
    let mut stream = UnixStream::connect(socket_path).unwrap();
    stream.write_all(json.as_bytes()).unwrap();
    stream.write_all(b"\n").unwrap();
    stream.flush().unwrap();

    let mut line = String::new();
    let mut reader = BufReader::new(stream);
    reader.read_line(&mut line).unwrap();
    serde_json::from_str(&line).unwrap()
}

#[test]
fn ping_over_socket_returns_version() {
    let base = unique_test_dir();
    let config_home = base.join("config");
    let runtime_dir = base.join("runtime");
    let socket_path = runtime_dir.join("herdr.sock");

    let mut child = spawn_herdr(&config_home, &runtime_dir, &socket_path);
    wait_for_socket(&socket_path, Duration::from_secs(5));

    let value = send_request(
        &socket_path,
        r#"{"id":"req_1","method":"ping","params":{}}"#,
    );
    assert_eq!(value["id"], "req_1");
    assert_eq!(value["result"]["type"], "pong");
    assert_eq!(value["result"]["version"], env!("CARGO_PKG_VERSION"));

    let _ = child.child.kill();
    let _ = child.child.wait();
    let _ = fs::remove_dir_all(base);
}

#[test]
fn workspace_list_and_create_round_trip() {
    let base = unique_test_dir();
    let config_home = base.join("config");
    let runtime_dir = base.join("runtime");
    let socket_path = runtime_dir.join("herdr.sock");

    let mut child = spawn_herdr(&config_home, &runtime_dir, &socket_path);
    wait_for_socket(&socket_path, Duration::from_secs(5));

    let empty = send_request(
        &socket_path,
        r#"{"id":"req_2","method":"workspace.list","params":{}}"#,
    );
    assert_eq!(empty["id"], "req_2");
    assert_eq!(empty["result"]["type"], "workspace_list");
    assert_eq!(empty["result"]["workspaces"].as_array().unwrap().len(), 0);

    let created = send_request(
        &socket_path,
        &format!(
            r#"{{"id":"req_3","method":"workspace.create","params":{{"cwd":"{}","focus":true}}}}"#,
            base.display()
        ),
    );
    assert_eq!(created["id"], "req_3");
    assert_eq!(created["result"]["type"], "workspace_info");
    assert_eq!(created["result"]["workspace"]["workspace_id"], "w_1");
    assert_eq!(created["result"]["workspace"]["number"], 1);
    assert_eq!(created["result"]["workspace"]["focused"], true);

    let listed = send_request(
        &socket_path,
        r#"{"id":"req_4","method":"workspace.list","params":{}}"#,
    );
    let workspaces = listed["result"]["workspaces"].as_array().unwrap();
    assert_eq!(workspaces.len(), 1);
    assert_eq!(workspaces[0]["workspace_id"], "w_1");

    let fetched = send_request(
        &socket_path,
        r#"{"id":"req_5","method":"workspace.get","params":{"workspace_id":"w_1"}}"#,
    );
    assert_eq!(fetched["result"]["workspace"]["workspace_id"], "w_1");

    let panes = send_request(
        &socket_path,
        r#"{"id":"req_6","method":"pane.list","params":{}}"#,
    );
    let panes = panes["result"]["panes"].as_array().unwrap();
    assert_eq!(panes.len(), 1);
    assert_eq!(panes[0]["workspace_id"], "w_1");
    let pane_id = panes[0]["pane_id"].as_str().unwrap().to_string();

    let pane = send_request(
        &socket_path,
        &format!(
            r#"{{"id":"req_7","method":"pane.get","params":{{"pane_id":"{}"}}}}"#,
            pane_id
        ),
    );
    assert_eq!(pane["result"]["pane"]["pane_id"], pane_id);

    let read = send_request(
        &socket_path,
        &format!(
            r#"{{"id":"req_8","method":"pane.read","params":{{"pane_id":"{}","source":"visible"}}}}"#,
            pane_id
        ),
    );
    assert_eq!(read["result"]["read"]["pane_id"], pane_id);
    assert!(read["result"]["read"]["text"].is_string());

    let send_text = send_request(
        &socket_path,
        &format!(
            r#"{{"id":"req_9","method":"pane.send_text","params":{{"pane_id":"{}","text":"echo alpha; echo beta; echo gamma"}}}}"#,
            pane_id
        ),
    );
    assert_eq!(send_text["result"]["type"], "ok");

    let send_enter = send_request(
        &socket_path,
        &format!(
            r#"{{"id":"req_10","method":"pane.send_keys","params":{{"pane_id":"{}","keys":["Enter"]}}}}"#,
            pane_id
        ),
    );
    assert_eq!(send_enter["result"]["type"], "ok");

    std::thread::sleep(Duration::from_millis(300));

    let recent = send_request(
        &socket_path,
        &format!(
            r#"{{"id":"req_11","method":"pane.read","params":{{"pane_id":"{}","source":"recent","lines":20}}}}"#,
            pane_id
        ),
    );
    let recent_text = recent["result"]["read"]["text"].as_str().unwrap();
    assert!(recent_text.contains("beta") || recent_text.contains("gamma"));

    let waited = send_request(
        &socket_path,
        &format!(
            r#"{{"id":"req_12","method":"pane.wait_for_output","params":{{"pane_id":"{}","source":"recent","lines":40,"match":{{"type":"substring","value":"gamma"}},"timeout_ms":2000}}}}"#,
            pane_id
        ),
    );
    assert_eq!(waited["result"]["type"], "output_matched");
    assert!(waited["result"]["matched_line"]
        .as_str()
        .unwrap()
        .contains("gamma"));
    assert!(waited["result"]["read"]["text"]
        .as_str()
        .unwrap()
        .contains("gamma"));

    let waited_regex = send_request(
        &socket_path,
        &format!(
            r#"{{"id":"req_13","method":"pane.wait_for_output","params":{{"pane_id":"{}","source":"recent","lines":40,"match":{{"type":"regex","value":"alp.*gamma"}},"timeout_ms":2000}}}}"#,
            pane_id
        ),
    );
    assert_eq!(waited_regex["result"]["type"], "output_matched");
    assert!(waited_regex["result"]["matched_line"]
        .as_str()
        .unwrap()
        .contains("alpha"));

    let timeout = send_request(
        &socket_path,
        &format!(
            r#"{{"id":"req_14","method":"pane.wait_for_output","params":{{"pane_id":"{}","source":"recent","lines":10,"match":{{"type":"substring","value":"definitely-not-there"}},"timeout_ms":200}}}}"#,
            pane_id
        ),
    );
    assert_eq!(timeout["error"]["code"], "timeout");

    let _ = child.child.kill();
    let _ = child.child.wait();
    let _ = fs::remove_dir_all(base);
}