use eyre::{eyre, Result};
use rand::{distributions::Alphanumeric, Rng};
use std::process::{Command, Stdio};
use std::{env, fs};

fn str_rnd(count: usize) -> String {
    rand::thread_rng()
        .sample_iter(&Alphanumeric)
        .take(count)
        .map(char::from)
        .collect()
}

fn exec(cmd: &str, args: Vec<&str>, inherit: bool) -> Result<Vec<String>> {
    let command = Command::new(cmd)
        .args(&args)
        .stdin(Stdio::null())
        .stdout(if inherit {
            Stdio::inherit()
        } else {
            Stdio::piped()
        })
        .stderr(if inherit {
            Stdio::inherit()
        } else {
            Stdio::piped()
        })
        .output()?;

    if command.status.success() {
        let output = String::from_utf8_lossy(&command.stdout).to_string();
        Ok(output
            .lines()
            .map(|s| s.to_string())
            .collect::<Vec<String>>())
    } else {
        Err(eyre!(
            "{} {:?} {} {}",
            cmd,
            args,
            String::from_utf8_lossy(&command.stdout).to_string(),
            String::from_utf8_lossy(&command.stderr).to_string()
        ))
    }
}

fn test_pr_result(pr: Vec<String>, key: &str) -> Result<()> {
    let pr_branch = format!("{key}-pr");
    let pr_msg = format!("pr: {key}");
    // let commit_msg = format!("commit: {key}");

    let mut created_pr_lines = pr.iter();
    assert!(created_pr_lines.next().unwrap().contains(&pr_msg));
    created_pr_lines.next();
    assert!(created_pr_lines.next().unwrap().contains(&pr_branch));
    // TODO: message is not getting into
    // assert!(created_pr_lines.any(|line| line.contains(&commit_msg)));

    Ok(())
}

fn test_pr() -> Result<()> {
    let key = str_rnd(12);

    let url = env::var("GR_GITHUB_REPOSITORY_URL")
        .unwrap_or("git@github.com:gr-bin-test/gr-bin-test.git".to_string());

    let base_dir = env::current_dir()?;
    let repositories_dir = base_dir.join("tests").join("repositories");
    let gr_path = base_dir.join("target/debug/gr");
    let gr = gr_path.to_str().unwrap();

    // Setup authentication and clone the repo
    env::set_current_dir(repositories_dir)?;
    exec("git", vec!["clone", &url, &key], true)?;
    env::set_current_dir(&key)?;

    // Checkout on new base branch, so we don't merge anything to any important
    let base_branch = format!("{key}-base");
    exec("git", vec!["checkout", "-b", &base_branch], true)?;
    exec("git", vec!["push", "-u", "origin", &base_branch], true)?;

    // Checkout to new child branch and create new commit
    let pr_branch = format!("{key}-pr");
    exec("git", vec!["checkout", "-b", &pr_branch], true)?;
    fs::File::create(&key)?;
    exec("git", vec!["add", "-A"], true)?;
    let commit_msg = format!("commit: {key}");
    exec("git", vec!["commit", "-m", &commit_msg], true)?;
    exec("git", vec!["push", "-u", "origin", &pr_branch], true)?;

    // Check that we don't have any PRs yet
    let no_pr = exec(gr, vec!["pr", "get"], false);
    assert!(no_pr.is_err());
    if let Err(err) = no_pr {
        assert!(err
            .to_string()
            .contains(&format!("Pull request on branch {pr_branch} not found.")));
    }

    // Create the PR
    let pr_msg = format!("pr: {key}");
    let created_pr = exec(gr, vec!["pr", "create", "-m", &pr_msg], false)?;
    test_pr_result(created_pr, &key)?;

    // Get the PR
    let got_pr = exec(gr, vec!["pr", "get"], false)?;
    test_pr_result(got_pr, &key)?;

    // List the PRs
    let listed_prs = exec(gr, vec!["pr", "list"], false)?;
    listed_prs.iter().any(|pr| pr.contains(&commit_msg));

    // TODO: Approve the PR - GitHub users cannot approve their own PRs
    // let approved_prs = exec(gr, vec!["pr", "approve"], false)?;
    // test_pr_result(approved_prs, &key)?;

    // Close the PR
    let closed_pr = exec(gr, vec!["pr", "close"], false)?;
    test_pr_result(closed_pr, &key)?;

    // Reopen and merge the PR, test that we change the branch to the base branch
    exec(
        gr,
        vec!["pr", "create", "-m", &pr_msg, "-t", &base_branch],
        true,
    )?;
    let got_pr = exec(gr, vec!["pr", "get"], false)?;
    test_pr_result(got_pr, &key)?;
    let merged_pr = exec(gr, vec!["pr", "merge"], false)?;
    test_pr_result(merged_pr, &key)?;
    let current_branch = exec("git", vec!["branch", "--show-current"], false)?;
    assert_eq!(current_branch.first().unwrap().trim(), &base_branch);

    // Delete created repositories
    env::set_current_dir("..")?;
    fs::remove_dir_all(&key)?;
    env::set_current_dir(&base_dir)?;

    Ok(())
}

#[test]
fn test_github_pr() {
    match test_pr() {
        Ok(()) => (),
        Err(err) => assert_eq!(err.to_string(), "^^^"),
    }
}