use std::process::Command;
use tempfile::TempDir;

fn arc_cmd() -> Command {
    let mut cmd = Command::new(env!("CARGO_BIN_EXE_arc"));
    cmd.env("NO_COLOR", "1");
    cmd
}

fn init_repo() -> TempDir {
    let dir = TempDir::new().unwrap();
    arc_cmd()
        .arg("init")
        .current_dir(dir.path())
        .output()
        .expect("failed to init");
    dir
}

#[test]
fn diff_no_changes_after_init() {
    let dir = init_repo();

    let output = arc_cmd()
        .arg("diff")
        .current_dir(dir.path())
        .output()
        .expect("failed to run arc");

    assert!(output.status.success());
    let stdout = String::from_utf8_lossy(&output.stdout);
    assert!(stdout.contains("no changes"));
}

#[test]
fn diff_shows_added_file() {
    let dir = init_repo();
    std::fs::write(dir.path().join("new.txt"), "hello\n").unwrap();

    let output = arc_cmd()
        .arg("diff")
        .current_dir(dir.path())
        .output()
        .expect("failed");

    assert!(output.status.success());
    let stdout = String::from_utf8_lossy(&output.stdout);
    assert!(stdout.contains("--- /dev/null"));
    assert!(stdout.contains("+++ b/new.txt"));
    assert!(stdout.contains("+hello"));
}

#[test]
fn diff_shows_modified_file() {
    let dir = init_repo();
    std::fs::write(dir.path().join("file.txt"), "original\n").unwrap();

    arc_cmd()
        .args(["commit", "add"])
        .current_dir(dir.path())
        .output()
        .expect("failed");

    std::fs::write(dir.path().join("file.txt"), "modified\n").unwrap();

    let output = arc_cmd()
        .arg("diff")
        .current_dir(dir.path())
        .output()
        .expect("failed");

    assert!(output.status.success());
    let stdout = String::from_utf8_lossy(&output.stdout);
    assert!(stdout.contains("--- a/file.txt"));
    assert!(stdout.contains("+++ b/file.txt"));
    assert!(stdout.contains("-original"));
    assert!(stdout.contains("+modified"));
}

#[test]
fn diff_shows_deleted_file() {
    let dir = init_repo();
    std::fs::write(dir.path().join("gone.txt"), "bye\n").unwrap();

    arc_cmd()
        .args(["commit", "add"])
        .current_dir(dir.path())
        .output()
        .expect("failed");

    std::fs::remove_file(dir.path().join("gone.txt")).unwrap();

    let output = arc_cmd()
        .arg("diff")
        .current_dir(dir.path())
        .output()
        .expect("failed");

    assert!(output.status.success());
    let stdout = String::from_utf8_lossy(&output.stdout);
    assert!(stdout.contains("--- a/gone.txt"));
    assert!(stdout.contains("+++ /dev/null"));
    assert!(stdout.contains("-bye"));
}

#[test]
fn diff_no_changes_after_commit() {
    let dir = init_repo();
    std::fs::write(dir.path().join("file.txt"), "content\n").unwrap();

    arc_cmd()
        .args(["commit", "add"])
        .current_dir(dir.path())
        .output()
        .expect("failed");

    let output = arc_cmd()
        .arg("diff")
        .current_dir(dir.path())
        .output()
        .expect("failed");

    assert!(output.status.success());
    let stdout = String::from_utf8_lossy(&output.stdout);
    assert!(stdout.contains("no changes"));
}

#[test]
fn diff_outside_repo_fails() {
    let dir = TempDir::new().unwrap();

    let output = arc_cmd()
        .arg("diff")
        .current_dir(dir.path())
        .output()
        .expect("failed");

    assert!(!output.status.success());
}

#[test]
fn diff_shows_header_with_path() {
    let dir = init_repo();
    std::fs::write(dir.path().join("test.txt"), "line\n").unwrap();

    let output = arc_cmd()
        .arg("diff")
        .current_dir(dir.path())
        .output()
        .expect("failed");

    assert!(output.status.success());
    let stdout = String::from_utf8_lossy(&output.stdout);
    assert!(stdout.contains("diff --arc a/test.txt b/test.txt"));
}

#[test]
fn diff_ignores_arcignore_patterns() {
    let dir = init_repo();
    std::fs::write(dir.path().join(".arcignore"), "*.tmp\n").unwrap();
    std::fs::write(dir.path().join("ignored.tmp"), "temp\n").unwrap();

    let output = arc_cmd()
        .arg("diff")
        .current_dir(dir.path())
        .output()
        .expect("failed");

    assert!(output.status.success());
    let stdout = String::from_utf8_lossy(&output.stdout);
    assert!(!stdout.contains("ignored.tmp"));
}