use assert_cmd::Command;
use assert_cmd::cargo::cargo_bin_cmd;
use predicates::prelude::*;
use std::fs;
use std::path::{Path, PathBuf};
use tempfile::TempDir;

/// A ginit run isolated from the machine it happens on: `init.defaultBranch`,
/// `user.name`/`user.email` and QuiCommit's own config all come from throwaway
/// locations, so expectations hold both on a developer box and in CI.
struct Scenario {
    work: TempDir,
    home: TempDir,
    config: PathBuf,
}

impl Scenario {
    fn new() -> Scenario {
        let work = TempDir::new().unwrap();
        let home = TempDir::new().unwrap();
        let config = home.path().join("config.toml");

        Scenario { work, home, config }
    }

    fn dir(&self) -> &Path {
        self.work.path()
    }

    fn command_in(&self, dir: &Path, args: &[&str]) -> Command {
        let mut cmd = cargo_bin_cmd!("quicommit");

        cmd.current_dir(dir)
            .env("HOME", self.home.path())
            .env("USERPROFILE", self.home.path())
            .env("XDG_CONFIG_HOME", self.home.path())
            .arg("--config")
            .arg(&self.config)
            .args(args);

        cmd
    }

    fn command(&self, args: &[&str]) -> Command {
        self.command_in(self.dir(), args)
    }

    /// `--yes` is the non-interactive side of ADR-0004; every case uses it
    /// because dialoguer refuses to answer without a terminal.
    fn ginit(&self, args: &[&str]) -> Command {
        let mut args: Vec<&str> = args.to_vec();
        args.push("--yes");

        self.command(&args)
    }

    fn git(&self, args: &[&str]) -> String {
        self.git_in(self.dir(), args)
    }

    fn git_in(&self, dir: &Path, args: &[&str]) -> String {
        let output = std::process::Command::new("git")
            .args(args)
            .current_dir(dir)
            .env("HOME", self.home.path())
            .env("USERPROFILE", self.home.path())
            .env("XDG_CONFIG_HOME", self.home.path())
            .output()
            .expect("git should be available");

        assert!(
            output.status.success(),
            "git {args:?} failed: {}",
            String::from_utf8_lossy(&output.stderr)
        );

        String::from_utf8_lossy(&output.stdout).trim().to_string()
    }

    fn read(&self, name: &str) -> String {
        fs::read_to_string(self.dir().join(name)).unwrap_or_else(|e| panic!("{name}: {e}"))
    }

    /// QuiCommit's config is written by hand rather than produced by
    /// `init --yes`, because on Windows libgit2 resolves the global git
    /// config from the user profile folder and ignores `HOME`, so a profile
    /// created by `init` would inherit this machine's real identity.
    fn write_config(&self, contents: &str) {
        fs::write(&self.config, contents).unwrap();
    }
}

#[test]
fn test_ginit_creates_repository_readme_and_gitignore() {
    let scenario = Scenario::new();

    scenario
        .ginit(&["ginit"])
        .assert()
        .success()
        .stdout(predicate::str::contains("Repository initialized"));

    assert!(scenario.dir().join(".git").exists());
    assert_eq!(
        scenario.git(&["symbolic-ref", "--short", "HEAD"]),
        "main",
        "with no init.defaultBranch configured, ginit starts on main"
    );

    let workdir = scenario.dir();
    let name = workdir.file_name().unwrap().to_string_lossy().to_string();
    assert_eq!(scenario.read("README.md"), format!("# {name}\n"));

    let gitignore = scenario.read(".gitignore");
    assert!(
        gitignore.contains(".env\n"),
        "the baseline must ignore .env, got: {gitignore}"
    );
    assert!(gitignore.contains("# Build output"));
}

#[test]
fn test_ginit_on_an_existing_repository_skips_creation_and_fills_gaps() {
    let scenario = Scenario::new();
    scenario.git(&["init"]);
    fs::write(scenario.dir().join("README.md"), "# mine\n").unwrap();

    // A repository whose HEAD has no commit yet still has a branch, and that
    // branch is what ginit must report as untouched.
    scenario.git(&["symbolic-ref", "HEAD", "refs/heads/trunk"]);

    scenario
        .ginit(&["ginit"])
        .assert()
        .success()
        // The branch line must name the branch that exists, not the default it
        // would have used for a fresh repository.
        .stdout(predicate::str::contains(
            "trunk (existing repository, branch untouched)",
        ));

    assert_eq!(scenario.read("README.md"), "# mine\n");
    assert!(
        scenario.dir().join(".gitignore").exists(),
        "the missing .gitignore should have been added"
    );
}

#[test]
fn test_ginit_never_touches_existing_start_files() {
    let scenario = Scenario::new();
    fs::write(scenario.dir().join("README.md"), "# mine\n").unwrap();
    fs::write(scenario.dir().join(".gitignore"), "keep-me/\n").unwrap();

    scenario
        .ginit(&["ginit"])
        .assert()
        .success()
        .stdout(predicate::str::contains(".gitignore sections").not());

    assert_eq!(scenario.read("README.md"), "# mine\n");
    assert_eq!(
        scenario.read(".gitignore"),
        "keep-me/\n",
        "ginit must not append to a maintained .gitignore"
    );
}

#[test]
fn test_ginit_branch_flag_sets_the_initial_branch() {
    let scenario = Scenario::new();

    scenario.ginit(&["ginit", "-b", "dev"]).assert().success();

    assert_eq!(scenario.git(&["symbolic-ref", "--short", "HEAD"]), "dev");
}

#[test]
fn test_ginit_refuses_to_rename_a_branch_that_has_commits() {
    let scenario = Scenario::new();
    scenario.git(&["init"]);
    scenario.git(&["config", "user.name", "Test User"]);
    scenario.git(&["config", "user.email", "test@example.com"]);
    scenario.git(&["config", "commit.gpgsign", "false"]);
    scenario.git(&["commit", "--allow-empty", "-m", "first"]);

    let branch = scenario.git(&["symbolic-ref", "--short", "HEAD"]);

    scenario
        .ginit(&["ginit", "-b", "experiment"])
        .assert()
        .success()
        .stdout(predicate::str::contains(
            "already has commits, branch unchanged",
        ));

    assert_eq!(scenario.git(&["symbolic-ref", "--short", "HEAD"]), branch);
}

#[test]
fn test_ginit_rejects_a_directory_inside_another_repository() {
    let scenario = Scenario::new();
    scenario.git(&["init"]);
    let nested = scenario.dir().join("inner");
    fs::create_dir(&nested).unwrap();

    scenario
        .command_in(&nested, &["ginit", "--yes"])
        .assert()
        .failure()
        .stderr(predicate::str::contains("inside the repository"));

    assert!(
        !nested.join(".git").exists(),
        "the nested directory must not become a repository"
    );
    assert!(
        !nested.join("README.md").exists(),
        "a refused run must write nothing at all"
    );
}

#[test]
fn test_ginit_add_names_the_new_remote_origin() {
    let scenario = Scenario::new();

    scenario
        .ginit(&["ginit", "--add", "https://example.com/origin.git"])
        .assert()
        .success();

    let remotes = scenario.git(&["remote", "-v"]);
    assert!(
        remotes.starts_with("origin"),
        "a bare URL should become origin, got: {remotes}"
    );
    assert!(remotes.contains("https://example.com/origin.git"));
}

#[test]
fn test_ginit_add_accepts_named_remotes_and_repeats() {
    let scenario = Scenario::new();

    scenario
        .ginit(&[
            "ginit",
            "--add",
            "upstream=https://example.com/upstream.git",
            "--add",
            "origin=https://example.com/origin.git",
        ])
        .assert()
        .success();

    let remotes = scenario.git(&["remote", "-v"]);
    assert!(remotes.contains("upstream"), "got: {remotes}");
    assert!(remotes.contains("origin"), "got: {remotes}");
}

#[test]
fn test_ginit_refuses_to_rewrite_an_existing_remote_url() {
    let scenario = Scenario::new();
    scenario
        .ginit(&["ginit", "--add", "https://example.com/first.git"])
        .assert()
        .success();

    scenario
        .ginit(&["ginit", "--add", "https://example.com/second.git"])
        .assert()
        .failure()
        .stderr(predicate::str::contains("set-url"));

    let remotes = scenario.git(&["remote", "-v"]);
    assert!(
        remotes.contains("https://example.com/first.git"),
        "the existing URL must survive, got: {remotes}"
    );
    assert!(!remotes.contains("second.git"), "got: {remotes}");
}

#[test]
fn test_ginit_rejects_an_add_value_without_a_url() {
    let scenario = Scenario::new();

    scenario
        .ginit(&["ginit", "--add", "origin"])
        .assert()
        .failure()
        .stderr(predicate::str::contains("--add 'origin' has no URL"));

    assert!(
        !scenario.dir().join(".git").exists(),
        "a rejected flag must stop the whole run"
    );
}

#[test]
fn test_ginit_gitignore_sections_follow_the_markers_in_the_directory() {
    struct Expected {
        markers: &'static [&'static str],
        present: &'static [&'static str],
        absent: &'static [&'static str],
    }

    let cases = [
        Expected {
            markers: &[],
            present: &["# Build output", "tmp/", ".env"],
            absent: &["# Rust", "# Node"],
        },
        Expected {
            markers: &["Cargo.toml"],
            present: &["# Rust", "target/"],
            absent: &["Cargo.lock", "# Node"],
        },
        Expected {
            markers: &["Cargo.toml", "package.json"],
            present: &["# Rust", "# Node", "node_modules/"],
            absent: &[],
        },
        Expected {
            markers: &["pyproject.toml"],
            present: &["# Python", "__pycache__/"],
            absent: &["# Ruby"],
        },
        Expected {
            markers: &["go.mod", "composer.json"],
            present: &["# Go", "vendor/"],
            absent: &["# PHP"],
        },
        Expected {
            markers: &["Cargo.toml", "pom.xml"],
            present: &["# Rust"],
            absent: &["# Maven"],
        },
    ];

    for case in cases {
        let scenario = Scenario::new();

        for marker in case.markers {
            fs::write(scenario.dir().join(marker), "").unwrap();
        }

        let assertion = scenario.ginit(&["ginit"]).assert().success();
        let stdout = String::from_utf8_lossy(&assertion.get_output().stdout).to_string();

        let gitignore = scenario.read(".gitignore");

        for expected in case.present {
            assert!(
                gitignore.contains(expected),
                "{:?} should contain {expected}, got: {gitignore}",
                case.markers
            );
        }

        for unexpected in case.absent {
            assert!(
                !gitignore.contains(unexpected),
                "{:?} should not contain {unexpected}, got: {gitignore}",
                case.markers
            );
        }

        // The preview promises exactly what the file delivers: a section the
        // cross-section dedupe dropped (PHP behind Go, Maven behind Rust) may
        // not be listed as if it were going to be written.
        assert!(
            stdout.contains(".gitignore sections:"),
            "the preview should list the sections, got: {stdout}"
        );

        for title in case.present.iter().filter(|line| line.starts_with('#')) {
            assert!(
                stdout.contains(title),
                "the preview should promise {title}, got: {stdout}"
            );
        }

        for title in case.absent.iter().filter(|line| line.starts_with('#')) {
            assert!(
                !stdout.contains(title),
                "the preview must not promise the dropped {title}, got: {stdout}"
            );
        }

        assert_eq!(
            gitignore.matches("dist/").count(),
            1,
            "entries shared with the baseline appear once, got: {gitignore}"
        );
        assert!(
            !gitignore.contains("\n\n\n"),
            "empty sections must be omitted, got: {gitignore}"
        );
    }
}

#[test]
fn test_ginit_dry_run_writes_nothing() {
    let scenario = Scenario::new();

    scenario
        .ginit(&[
            "ginit",
            "--dry-run",
            "-b",
            "dev",
            "--add",
            "https://example.com/origin.git",
        ])
        .assert()
        .success()
        .stdout(predicate::str::contains("Dry run"))
        .stdout(predicate::str::contains("dev"));

    assert!(
        !scenario.dir().join(".git").exists(),
        "a dry run must not even create the repository"
    );
    assert!(!scenario.dir().join("README.md").exists());
    assert!(!scenario.dir().join(".gitignore").exists());
}

#[test]
fn test_ginit_yes_keeps_every_planned_line_of_the_output() {
    let scenario = Scenario::new();
    fs::write(scenario.dir().join("Cargo.toml"), "").unwrap();

    let output = scenario
        .ginit(&["ginit", "--add", "https://example.com/origin.git"])
        .output()
        .unwrap();

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

    let stdout = String::from_utf8_lossy(&output.stdout);

    // ADR-0004: --yes only removes the question, so the same artifacts the
    // preview promised are still reported and still on disk.
    for expected in ["README.md", ".gitignore", "origin", "Initial branch"] {
        assert!(stdout.contains(expected), "stdout was: {stdout}");
    }

    assert!(
        !stdout.contains("Create these now?"),
        "--yes must not prompt, stdout was: {stdout}"
    );
    assert!(scenario.read(".gitignore").contains("# Rust"));
    assert!(scenario.git(&["remote", "-v"]).contains("origin"));
}

#[test]
fn test_ginit_readme_title_survives_spaces_and_unicode() {
    for name in ["my project", "中文 项目", "Ünïcödé-ß"] {
        let scenario = Scenario::new();
        let titled = scenario.dir().join(name);
        fs::create_dir(&titled).unwrap();

        scenario
            .command_in(&titled, &["ginit", "--yes"])
            .assert()
            .success();

        let readme = fs::read_to_string(titled.join("README.md")).unwrap();
        assert_eq!(readme, format!("# {name}\n"));
    }
}

#[test]
fn test_ginit_profile_applies_identity_and_records_the_mapping() {
    let scenario = Scenario::new();
    scenario.write_config(
        r#"version = "1"

[profiles.work]
name = "work"
user_name = "Work User"
user_email = "work@example.com"
"#,
    );

    scenario
        .ginit(&["ginit", "--profile", "work"])
        .assert()
        .success();

    assert_eq!(
        scenario.git(&["config", "--local", "user.email"]),
        "work@example.com"
    );

    let config = fs::read_to_string(&scenario.config).unwrap();
    assert!(
        config.contains("[repo_profiles]"),
        "the directory should be mapped to the profile, got: {config}"
    );
}

#[test]
fn test_ginit_missing_profile_fails_without_writing_config() {
    let scenario = Scenario::new();
    scenario.write_config(
        r#"version = "1"

[profiles.work]
name = "work"
user_name = "Work User"
user_email = "work@example.com"
"#,
    );
    let config_before = fs::read_to_string(&scenario.config).unwrap();

    scenario
        .ginit(&["ginit", "--profile", "nope"])
        .assert()
        .failure()
        .stderr(predicate::str::contains("profile add"));

    assert_eq!(
        fs::read_to_string(&scenario.config).unwrap(),
        config_before,
        "a rejected profile must leave the config untouched"
    );
}

#[test]
fn test_ginit_hints_at_pushing_after_the_first_commit() {
    let scenario = Scenario::new();

    scenario
        .ginit(&["ginit", "--add", "https://example.com/origin.git"])
        .assert()
        .success()
        // The label already ends in a colon; matching the newline guards the
        // doubled colon that `println!("{}:", …)` would produce.
        .stdout(predicate::str::contains("Next steps:\n"))
        .stdout(predicate::str::contains("quicommit commit --push"));
}

#[test]
fn test_ginit_on_a_bare_repository_skips_files_and_still_adds_the_remote() {
    let scenario = Scenario::new();
    scenario.git(&["init", "--bare"]);

    scenario
        .ginit(&["ginit", "--add", "https://example.com/mirror.git"])
        .assert()
        .success();

    assert!(!scenario.dir().join("README.md").exists());
    assert!(!scenario.dir().join(".gitignore").exists());
    assert!(
        scenario
            .git(&["config", "--local", "remote.origin.url"])
            .contains("https://example.com/mirror.git")
    );
}