//! Integration tests for the `envdiff` command.

use std::fs;
use std::path::PathBuf;
use std::sync::atomic::{AtomicU64, Ordering};

use assert_cmd::Command;
use predicates::prelude::*;

fn cargo_command() -> Command {
    Command::cargo_bin("envdiff").expect("binary")
}

struct TempTestDir {
    path: PathBuf,
}

impl TempTestDir {
    fn path(&self) -> &std::path::Path {
        &self.path
    }
}

impl Drop for TempTestDir {
    fn drop(&mut self) {
        let _ = fs::remove_dir_all(&self.path);
    }
}

#[test]
fn runs_cmd_and_reports_environment_diff_as_json() {
    let temp = unique_temp_dir();
    let script = temp.path().join("mutate.cmd");
    fs::write(
        &script,
        "@echo off\r\nset TEST_FLAG=enabled\r\nset PATH=%PATH%;C:\\Mercury\\Bin\r\n",
    )
    .expect("script");

    let mut command = cargo_command();
    command
        .arg("run")
        .arg("--json")
        .arg("--shell")
        .arg("cmd")
        .arg("--")
        .arg(&script)
        .assert()
        .success()
        .stdout(predicate::str::contains("\"added\""))
        .stdout(predicate::str::contains("\"name\":\"TEST_FLAG\""))
        .stdout(predicate::str::contains("\"path_like_changes\""));
}

#[test]
fn help_includes_envdiff_examples() {
    let mut command = cargo_command();
    command
        .arg("--help")
        .assert()
        .success()
        .stdout(predicate::str::contains("snapshot"))
        .stdout(predicate::str::contains("run --shell cmd"))
        .stdout(predicate::str::contains("ConvertFrom-Json"));
}

fn unique_temp_dir() -> TempTestDir {
    static NEXT_ID: AtomicU64 = AtomicU64::new(0);

    loop {
        let unique = NEXT_ID.fetch_add(1, Ordering::Relaxed);
        let path =
            std::env::temp_dir().join(format!("envdiff-test-{}-{unique}", std::process::id()));
        match fs::create_dir(&path) {
            Ok(()) => return TempTestDir { path },
            Err(error) if error.kind() == std::io::ErrorKind::AlreadyExists => {}
            Err(error) => panic!("tempdir: {error}"),
        }
    }
}