use anyhow::Result;
use assert_cmd::{cargo::cargo_bin, Command};
use rexpect::session::{spawn_command, PtySession};
use shackle_shell::user_info::{get_user_groups, get_username};
use std::path::{Path, PathBuf};
use tempfile::TempDir;

struct TestContext {
    p: PtySession,
    workdir: TempDir,
}

impl TestContext {
    fn personal_repo_dir(&self, repo_name: &str) -> PathBuf {
        let username = get_username().unwrap();
        self.workdir
            .as_ref()
            .join("git")
            .join(username)
            .join(&format!("{}.git", repo_name))
    }

    fn group_repo_dir(&self, group: &str, repo_name: &str) -> PathBuf {
        self.workdir
            .as_ref()
            .join("git")
            .join(group)
            .join(&format!("{}.git", repo_name))
    }
}

fn personal_repo_path(repo_name: &str) -> String {
    let username = get_username().unwrap();
    format!("git/{username}/{repo_name}.git")
}

fn arbitrary_user_group() -> String {
    get_user_groups().into_iter().next().unwrap()
}

fn group_repo_path(group: &str, repo_name: &str) -> String {
    format!("git/{group}/{repo_name}.git")
}

fn spawn_interactive_process() -> Result<TestContext> {
    let workdir = tempfile::tempdir()?;

    let path = cargo_bin(env!("CARGO_PKG_NAME"));
    let mut command = std::process::Command::new(&path);
    command.current_dir(&workdir);
    let mut p = spawn_command(command, Some(3000))?;
    expect_prompt(&mut p)?;
    Ok(TestContext { p, workdir })
}

fn run_batch_command(batch_command: &str) -> Result<TestContext> {
    let workdir = tempfile::tempdir()?;

    let path = cargo_bin(env!("CARGO_PKG_NAME"));
    let mut command = std::process::Command::new(&path);
    command.current_dir(&workdir);
    command.args(["-c", batch_command]);
    let p = spawn_command(command, Some(3000))?;

    Ok(TestContext { p, workdir })
}

fn expect_prompt(p: &mut PtySession) -> Result<()> {
    p.exp_string("> ")?;
    Ok(())
}

#[test]
fn shows_a_prompt() -> Result<()> {
    spawn_interactive_process()?;
    Ok(())
}

#[test]
fn does_nothing_after_receiving_whitespace_input() -> Result<()> {
    let mut c = spawn_interactive_process()?;
    c.p.send_line("")?;
    expect_prompt(&mut c.p)?;
    c.p.send_line("  ")?;
    expect_prompt(&mut c.p)?;
    Ok(())
}

#[test]
fn quits_when_eof_is_sent() -> Result<()> {
    let mut c = spawn_interactive_process()?;
    c.p.send_control('d')?;
    c.p.exp_eof()?;
    Ok(())
}

#[test]
fn quits_when_exit_command_is_sent() -> Result<()> {
    let mut c = spawn_interactive_process()?;
    c.p.send_line("exit")?;
    c.p.exp_eof()?;
    Ok(())
}

#[test]
fn reports_error_with_unsupported_shell_commands() -> Result<()> {
    let mut c = spawn_interactive_process()?;
    c.p.send_line("ls")?;
    c.p.exp_string("error: unrecognized subcommand 'ls'")?;
    expect_prompt(&mut c.p)?;
    Ok(())
}

#[test]
fn reports_error_with_nonsense_input() -> Result<()> {
    let mut c = spawn_interactive_process()?;
    c.p.send_line(" asd fg  ")?;
    c.p.exp_string("error: unrecognized subcommand 'asd'")?;
    expect_prompt(&mut c.p)?;
    Ok(())
}

fn verify_repo_exists(repo_dir: &Path) {
    Command::new("git")
        .arg("rev-list")
        .arg("--all")
        .current_dir(repo_dir)
        .assert()
        .success()
        .stdout("");
}

fn verify_repo_does_not_exist(repo_dir: &Path) {
    assert!(!repo_dir.exists());
}

fn verify_current_branch(repo_dir: &Path, expected_ref: &str) {
    Command::new("git")
        .arg("symbolic-ref")
        .arg("HEAD")
        .current_dir(repo_dir)
        .assert()
        .success()
        .stdout(format!("{expected_ref}\n"));
}

fn verify_repo_config_value(repo_dir: &Path, config_key: &str, config_value: Option<&str>) {
    let assert = Command::new("git")
        .args(["config", "--local", config_key])
        .current_dir(repo_dir)
        .assert();
    match config_value {
        Some(value) => {
            assert.success().stdout(format!("{value}\n"));
        }
        None => {
            assert.failure().code(1);
        }
    }
}

#[test]
fn can_init_a_new_git_repo() -> Result<()> {
    let mut c = spawn_interactive_process()?;
    let repo_name = "my-new-repo";
    c.p.send_line(&format!("init {}", repo_name))?;
    c.p.exp_string(&format!(
        "Successfully created \"{}\"",
        personal_repo_path(repo_name)
    ))?;
    expect_prompt(&mut c.p)?;

    let repo_dir = c.personal_repo_dir(repo_name);
    verify_repo_exists(&repo_dir);
    verify_current_branch(&repo_dir, "refs/heads/main");
    verify_repo_config_value(&repo_dir, "core.sharedrepository", None);

    Ok(())
}

#[test]
fn can_init_a_new_shared_git_repo() -> Result<()> {
    let mut c = spawn_interactive_process()?;
    let group = arbitrary_user_group();
    let repo_name = "my-new-shared-repo";
    c.p.send_line(&format!("init --group {} {}", group, repo_name))?;
    c.p.exp_string(&format!(
        "Successfully created \"{}\"",
        group_repo_path(&group, repo_name)
    ))?;
    expect_prompt(&mut c.p)?;

    let repo_dir = c.group_repo_dir(&group, repo_name);
    verify_repo_exists(&repo_dir);
    verify_repo_config_value(&repo_dir, "core.sharedrepository", Some("1"));

    Ok(())
}

#[test]
fn does_not_init_shared_repo_if_the_user_isnt_in_the_group() -> Result<()> {
    let mut c = spawn_interactive_process()?;
    let group = "not-a-real-group";
    let repo_name = "my-new-shared-repo";
    c.p.send_line(&format!("init --group {} {}", group, repo_name))?;
    c.p.exp_string("Unknown group")?;

    Ok(())
}

#[test]
fn runs_a_single_command_and_exit_with_cli_flag() -> Result<()> {
    let repo_name = "another-new-repo";
    let mut c = run_batch_command(&format!("init {}", repo_name))?;
    c.p.exp_string(&format!(
        "Successfully created \"{}\"",
        personal_repo_path(repo_name)
    ))?;
    c.p.exp_eof()?;
    Ok(())
}

#[test]
fn allows_quotes_arguments() -> Result<()> {
    let repo_name = "another-new-repo";
    let mut c = spawn_interactive_process()?;
    c.p.send_line(&format!("\"init\" '{repo_name}'"))?;
    c.p.exp_string(&format!(
        "Successfully created \"{}\"",
        personal_repo_path(repo_name)
    ))?;
    Ok(())
}

#[test]
fn errors_with_an_open_double_quote() -> Result<()> {
    let mut c = spawn_interactive_process()?;
    c.p.send_line("\"init 'another-new-repo'")?;
    c.p.exp_string("Incomplete input")?;
    Ok(())
}

#[test]
fn errors_with_an_open_single_quote() -> Result<()> {
    let mut c = spawn_interactive_process()?;
    c.p.send_line("'init 'another-new-repo'")?;
    c.p.exp_string("Incomplete input")?;
    Ok(())
}

#[test]
fn allows_single_quotes_and_spaces_inside_double_quotes() -> Result<()> {
    let repo_name = "shukkie's new repo";
    let mut c = spawn_interactive_process()?;
    c.p.send_line(&format!("init \"{repo_name}\""))?;
    c.p.exp_string(&format!(
        "Successfully created \"{}\"",
        personal_repo_path(repo_name)
    ))?;
    Ok(())
}

const DEFAULT_DESCRIPTION: &str =
    "Unnamed repository; edit this file 'description' to name the repository.";

fn expect_list_table(c: &mut TestContext, repos: &[(String, String)]) -> Result<()> {
    c.p.send_line("list")?;
    c.p.exp_regex(r"\+-+\+-+\+")?;
    c.p.exp_regex(r"\| path +\| description +\|")?;
    c.p.exp_regex(r"\+=+\+")?;
    for (path, description) in repos {
        c.p.exp_string("| ")?;
        c.p.exp_string(path)?;
        c.p.exp_regex(r" +\| ")?;
        c.p.exp_string(&description)?;
        c.p.exp_regex(r" +\|")?;
    }
    c.p.exp_regex(r"\+-+\+-+\+")?;
    expect_prompt(&mut c.p)?;
    Ok(())
}

#[test]
fn list_can_print_an_empty_list() -> Result<()> {
    let mut c = spawn_interactive_process()?;
    expect_list_table(&mut c, &[])?;

    Ok(())
}

#[test]
fn list_can_print_a_list_of_personal_repos_with_descriptions() -> Result<()> {
    let mut c = spawn_interactive_process()?;
    let repo_name = "my-personal-repo";
    c.p.send_line(&format!("init {}", repo_name))?;
    c.p.exp_string(&format!(
        "Successfully created \"{}\"",
        personal_repo_path(repo_name)
    ))?;
    expect_prompt(&mut c.p)?;

    expect_list_table(
        &mut c,
        &[(
            personal_repo_path(repo_name),
            DEFAULT_DESCRIPTION.to_owned(),
        )],
    )?;

    Ok(())
}

#[test]
fn list_can_print_a_list_of_all_repos_with_descriptions() -> Result<()> {
    let mut c = spawn_interactive_process()?;
    let personal_repo_name = "my-personal-repo";
    c.p.send_line(&format!("init {}", personal_repo_name))?;
    c.p.exp_string(&format!(
        "Successfully created \"{}\"",
        personal_repo_path(personal_repo_name)
    ))?;
    expect_prompt(&mut c.p)?;

    let group = arbitrary_user_group();
    let shared_repo_name = "my-shared-repo";
    c.p.send_line(&format!("init --group {} {}", group, shared_repo_name))?;
    c.p.exp_string(&format!(
        "Successfully created \"{}\"",
        group_repo_path(&group, shared_repo_name)
    ))?;
    expect_prompt(&mut c.p)?;

    expect_list_table(
        &mut c,
        &[
            (
                personal_repo_path(personal_repo_name),
                DEFAULT_DESCRIPTION.to_owned(),
            ),
            (
                group_repo_path(&group, shared_repo_name),
                DEFAULT_DESCRIPTION.to_owned(),
            ),
        ],
    )?;

    Ok(())
}

#[test]
fn can_set_the_description_on_a_repo_during_init() -> Result<()> {
    let mut c = spawn_interactive_process()?;
    let repo_name = "my-personal-repo";
    let description = "A cool repo that does cool things";
    c.p.send_line(&format!("init --description \"{description}\" {repo_name}"))?;
    c.p.exp_string(&format!(
        "Successfully created \"{}\"",
        personal_repo_path(repo_name)
    ))?;

    expect_list_table(
        &mut c,
        &[(personal_repo_path(repo_name), description.to_owned())],
    )?;

    Ok(())
}

#[test]
fn can_change_the_description_on_a_repo() -> Result<()> {
    let mut c = spawn_interactive_process()?;
    let repo_name = "my-personal-repo";
    let description = "A cool repo that does cool things";
    let repo_path = personal_repo_path(repo_name);
    c.p.send_line(&format!("init {repo_name}"))?;
    c.p.exp_string(&format!("Successfully created \"{repo_path}\"",))?;
    c.p.send_line(&format!(
        "set-description \"{repo_path}\" \"{description}\""
    ))?;
    c.p.exp_string("Successfully updated description")?;
    expect_prompt(&mut c.p)?;
    expect_list_table(&mut c, &[(repo_path, description.to_owned())])?;

    Ok(())
}

#[test]
fn can_set_the_main_branch_of_a_new_git_repo() -> Result<()> {
    let mut c = spawn_interactive_process()?;
    let repo_name = "my-new-repo";
    let main_branch = "foobar";
    c.p.send_line(&format!("init --branch {} {}", main_branch, repo_name))?;
    c.p.exp_string(&format!(
        "Successfully created \"{}\"",
        personal_repo_path(repo_name)
    ))?;

    let repo_dir = c.personal_repo_dir(repo_name);
    verify_current_branch(&repo_dir, &format!("refs/heads/{main_branch}"));

    Ok(())
}

#[test]
fn can_change_the_main_branch_on_a_repo() -> Result<()> {
    let mut c = spawn_interactive_process()?;
    let repo_name = "my-new-repo";
    let main_branch = "foobar";
    let repo_path = personal_repo_path(repo_name);

    c.p.send_line(&format!("init {}", repo_name))?;
    c.p.exp_string(&format!("Successfully created \"{repo_path}\""))?;

    c.p.send_line(&format!("set-branch \"{repo_path}\" \"{main_branch}\""))?;
    c.p.exp_string("Successfully updated branch")?;

    let repo_dir = c.personal_repo_dir(repo_name);
    verify_current_branch(&repo_dir, &format!("refs/heads/{main_branch}"));

    Ok(())
}

#[test]
fn can_delete_a_repo() -> Result<()> {
    let mut c = spawn_interactive_process()?;
    let repo_name = "an-old-repo";
    let repo_path = personal_repo_path(repo_name);
    let repo_dir = c.personal_repo_dir(repo_name);

    c.p.send_line(&format!("init {}", repo_name))?;
    c.p.exp_string(&format!("Successfully created \"{repo_path}\""))?;
    verify_repo_exists(&repo_dir);

    c.p.send_line(&format!("delete \"{repo_path}\""))?;
    c.p.exp_string(&format!("Successfully deleted \"{repo_path}\""))?;
    verify_repo_does_not_exist(&repo_dir);

    Ok(())
}