use crate::common::*;

use pretty_assertions::assert_eq;

macro_rules! test {
  (
    name:       $name:ident,
    $(justfile: $justfile:expr,)?
    $(args:     ($($arg:tt),*),)?
    $(env:      { $($env_key:literal : $env_value:literal,)* },)?
    $(stdin:    $stdin:expr,)?
    $(stdout:   $stdout:expr,)?
    $(stderr:   $stderr:expr,)?
    $(status:   $status:expr,)?
    $(shell:    $shell:expr,)?
  ) => {
    #[test]
    fn $name() {
      let test = crate::test::Test::new();

      $($(let test = test.arg($arg);)*)?
      $($(let test = test.env($env_key, $env_value);)*)?
      $(let test = test.justfile($justfile);)?
      $(let test = test.shell($shell);)?
      $(let test = test.status($status);)?
      $(let test = test.stderr($stderr);)?
      $(let test = test.stdin($stdin);)?
      $(let test = test.stdout($stdout);)?

      test.run();
    }
  }
}

pub(crate) struct Test {
  pub(crate) args: Vec<String>,
  pub(crate) current_dir: PathBuf,
  pub(crate) env: BTreeMap<String, String>,
  pub(crate) justfile: Option<String>,
  pub(crate) shell: bool,
  pub(crate) status: i32,
  pub(crate) stderr: String,
  pub(crate) stderr_regex: Option<Regex>,
  pub(crate) stdin: String,
  pub(crate) stdout: String,
  pub(crate) suppress_dotenv_load_warning: bool,
  pub(crate) tempdir: TempDir,
}

impl Test {
  pub(crate) fn new() -> Self {
    Self::with_tempdir(tempdir())
  }

  pub(crate) fn with_tempdir(tempdir: TempDir) -> Self {
    Self {
      args: Vec::new(),
      current_dir: PathBuf::new(),
      env: BTreeMap::new(),
      justfile: Some(String::new()),
      shell: true,
      status: EXIT_SUCCESS,
      stderr: String::new(),
      stderr_regex: None,
      stdin: String::new(),
      stdout: String::new(),
      suppress_dotenv_load_warning: true,
      tempdir,
    }
  }

  pub(crate) fn arg(mut self, val: &str) -> Self {
    self.args.push(val.to_owned());
    self
  }

  pub(crate) fn args(mut self, args: &[&str]) -> Self {
    for arg in args {
      self = self.arg(arg);
    }
    self
  }

  pub(crate) fn current_dir(mut self, path: impl AsRef<Path>) -> Self {
    self.current_dir = path.as_ref().to_owned();
    self
  }

  pub(crate) fn env(mut self, key: &str, val: &str) -> Self {
    self.env.insert(key.to_string(), val.to_string());
    self
  }

  pub(crate) fn justfile(mut self, justfile: impl Into<String>) -> Self {
    self.justfile = Some(justfile.into());
    self
  }

  pub(crate) fn justfile_path(&self) -> PathBuf {
    self.tempdir.path().join("justfile")
  }

  pub(crate) fn no_justfile(mut self) -> Self {
    self.justfile = None;
    self
  }

  pub(crate) fn shell(mut self, shell: bool) -> Self {
    self.shell = shell;
    self
  }

  pub(crate) fn status(mut self, exit_status: i32) -> Self {
    self.status = exit_status;
    self
  }

  pub(crate) fn stderr(mut self, stderr: impl Into<String>) -> Self {
    self.stderr = stderr.into();
    self
  }

  pub(crate) fn stderr_regex(mut self, stderr_regex: impl AsRef<str>) -> Self {
    self.stderr_regex = Some(Regex::new(&format!("^{}$", stderr_regex.as_ref())).unwrap());
    self
  }

  pub(crate) fn stdin(mut self, stdin: impl Into<String>) -> Self {
    self.stdin = stdin.into();
    self
  }

  pub(crate) fn stdout(mut self, stdout: impl Into<String>) -> Self {
    self.stdout = stdout.into();
    self
  }

  pub(crate) fn suppress_dotenv_load_warning(mut self, suppress_dotenv_load_warning: bool) -> Self {
    self.suppress_dotenv_load_warning = suppress_dotenv_load_warning;
    self
  }

  pub(crate) fn tree(self, mut tree: Tree) -> Self {
    tree.map(|_name, content| unindent(content));
    tree.instantiate(&self.tempdir.path()).unwrap();
    self
  }
}

impl Test {
  pub(crate) fn run(self) -> TempDir {
    if let Some(justfile) = &self.justfile {
      let justfile = unindent(justfile);
      fs::write(self.justfile_path(), justfile).unwrap();
    }

    let stdout = unindent(&self.stdout);
    let stderr = unindent(&self.stderr);

    let mut dotenv_path = self.tempdir.path().to_path_buf();
    dotenv_path.push(".env");
    fs::write(dotenv_path, "DOTENV_KEY=dotenv-value").unwrap();

    let mut command = Command::new(&executable_path("just"));

    if self.shell {
      command.args(&["--shell", "bash"]);
    }

    let mut child = command
      .args(self.args)
      .envs(&self.env)
      .env(
        "JUST_SUPPRESS_DOTENV_LOAD_WARNING",
        if self.suppress_dotenv_load_warning {
          "1"
        } else {
          "0"
        },
      )
      .current_dir(self.tempdir.path().join(self.current_dir))
      .stdin(Stdio::piped())
      .stdout(Stdio::piped())
      .stderr(Stdio::piped())
      .spawn()
      .expect("just invocation failed");

    {
      let mut stdin_handle = child.stdin.take().expect("failed to unwrap stdin handle");

      stdin_handle
        .write_all(self.stdin.as_bytes())
        .expect("failed to write stdin to just process");
    }

    let output = child
      .wait_with_output()
      .expect("failed to wait for just process");

    fn compare<T: PartialEq + Debug>(name: &str, have: T, want: T) -> bool {
      let equal = have == want;
      if !equal {
        eprintln!("Bad {}: {}", name, Comparison::new(&have, &want));
      }
      equal
    }

    let output_stderr = str::from_utf8(&output.stderr).unwrap();

    if let Some(ref stderr_regex) = self.stderr_regex {
      if !stderr_regex.is_match(output_stderr) {
        panic!(
          "Stderr regex mismatch: {} !~= /{}/",
          output_stderr, stderr_regex
        );
      }
    }

    if !compare("status", output.status.code().unwrap(), self.status)
      | !compare("stdout", str::from_utf8(&output.stdout).unwrap(), &stdout)
      | (self.stderr_regex.is_none() && !compare("stderr", output_stderr, &stderr))
    {
      panic!("Output mismatch.");
    }

    if self.status == EXIT_SUCCESS {
      test_round_trip(self.tempdir.path());
    }

    self.tempdir
  }
}

#[derive(PartialEq, Debug)]
struct Output<'a> {
  stdout: &'a str,
  stderr: &'a str,
  status: i32,
}

fn test_round_trip(tmpdir: &Path) {
  println!("Reparsing...");

  let output = Command::new(&executable_path("just"))
    .current_dir(tmpdir)
    .arg("--dump")
    .output()
    .expect("just invocation failed");

  if !output.status.success() {
    panic!("dump failed: {}", output.status);
  }

  let dumped = String::from_utf8(output.stdout).unwrap();

  let reparsed_path = tmpdir.join("reparsed.just");

  fs::write(&reparsed_path, &dumped).unwrap();

  let output = Command::new(&executable_path("just"))
    .current_dir(tmpdir)
    .arg("--justfile")
    .arg(&reparsed_path)
    .arg("--dump")
    .output()
    .expect("just invocation failed");

  if !output.status.success() {
    panic!("reparse failed: {}", output.status);
  }

  let reparsed = String::from_utf8(output.stdout).unwrap();

  assert_eq!(reparsed, dumped, "reparse mismatch");
}