use std::ffi::OsStr;
use std::fs;
use std::os::unix::fs::MetadataExt;
use std::path::Component;
use std::path::PathBuf;
use std::process::Command;
use std::{env::var, path::Path};

use crate::command::CommandExt;
use crate::{Step, HOME_DIR};
use color_eyre::eyre::eyre;
use color_eyre::eyre::Context;
use color_eyre::eyre::Result;
use home;
use ini::Ini;
use tracing::debug;

#[cfg(target_os = "linux")]
use super::linux::Distribution;
use crate::error::SkipStep;
use crate::execution_context::ExecutionContext;
#[cfg(any(target_os = "linux", target_os = "macos"))]
use crate::executor::Executor;
#[cfg(any(target_os = "linux", target_os = "macos"))]
use crate::executor::RunType;
use crate::terminal::print_separator;
use crate::utils::{require, require_option, PathExt, REQUIRE_SUDO};

#[cfg(any(target_os = "linux", target_os = "macos"))]
const INTEL_BREW: &str = "/usr/local/bin/brew";

#[cfg(any(target_os = "linux", target_os = "macos"))]
const ARM_BREW: &str = "/opt/homebrew/bin/brew";

#[derive(Copy, Clone, Debug)]
#[allow(dead_code)]
#[cfg(any(target_os = "linux", target_os = "macos"))]
pub enum BrewVariant {
    Path,
    MacIntel,
    MacArm,
}

#[cfg(any(target_os = "linux", target_os = "macos"))]
impl BrewVariant {
    fn binary_name(self) -> &'static str {
        match self {
            BrewVariant::Path => "brew",
            BrewVariant::MacIntel => INTEL_BREW,
            BrewVariant::MacArm => ARM_BREW,
        }
    }

    #[cfg(target_os = "macos")]
    fn is_path(&self) -> bool {
        matches!(self, BrewVariant::Path)
    }

    fn both_both_exist() -> bool {
        Path::new(INTEL_BREW).exists() && Path::new(ARM_BREW).exists()
    }

    pub fn step_title(self) -> &'static str {
        let both_exists = Self::both_both_exist();
        match self {
            BrewVariant::MacArm if both_exists => "Brew (ARM)",
            BrewVariant::MacIntel if both_exists => "Brew (Intel)",
            _ => "Brew",
        }
    }

    fn execute(self, run_type: RunType) -> Executor {
        match self {
            BrewVariant::MacIntel if cfg!(target_arch = "aarch64") => {
                let mut command = run_type.execute("arch");
                command.arg("-x86_64").arg(self.binary_name());
                command
            }
            BrewVariant::MacArm if cfg!(target_arch = "x86_64") => {
                let mut command = run_type.execute("arch");
                command.arg("-arm64e").arg(self.binary_name());
                command
            }
            _ => run_type.execute(self.binary_name()),
        }
    }

    #[cfg(target_os = "macos")]
    fn is_macos_custom(binary_name: PathBuf) -> bool {
        !(binary_name.as_os_str() == INTEL_BREW || binary_name.as_os_str() == ARM_BREW)
    }
}

pub fn run_fisher(ctx: &ExecutionContext) -> Result<()> {
    let fish = require("fish")?;

    Command::new(&fish)
        .args(["-c", "type -t fisher"])
        .output_checked_utf8()
        .map(|_| ())
        .map_err(|_| SkipStep("`fisher` is not defined in `fish`".to_owned()))?;

    Command::new(&fish)
        .args(["-c", "echo \"$__fish_config_dir/fish_plugins\""])
        .output_checked_utf8()
        .and_then(|output| Path::new(&output.stdout.trim()).require().map(|_| ()))
        .map_err(|err| SkipStep(format!("`fish_plugins` path doesn't exist: {err}")))?;

    Command::new(&fish)
        .args(["-c", "fish_update_completions"])
        .output_checked_utf8()
        .map(|_| ())
        .map_err(|_| SkipStep("`fish_update_completions` is not available".to_owned()))?;

    print_separator("Fisher");

    let version_str = ctx
        .run_type()
        .execute(&fish)
        .args(["-c", "fisher --version"])
        .output_checked_utf8()?
        .stdout;
    debug!("Fisher version: {}", version_str);

    if version_str.starts_with("fisher version 3.") {
        // v3 - see https://github.com/topgrade-rs/topgrade/pull/37#issuecomment-1283844506
        ctx.run_type().execute(&fish).args(["-c", "fisher"]).status_checked()
    } else {
        // v4
        ctx.run_type()
            .execute(&fish)
            .args(["-c", "fisher update"])
            .status_checked()
    }
}

pub fn run_bashit(ctx: &ExecutionContext) -> Result<()> {
    HOME_DIR.join(".bash_it").require()?;

    print_separator("Bash-it");

    ctx.run_type()
        .execute("bash")
        .args(["-lic", &format!("bash-it update {}", ctx.config().bashit_branch())])
        .status_checked()
}

pub fn run_oh_my_bash(ctx: &ExecutionContext) -> Result<()> {
    require("bash")?;
    let oh_my_bash = var("OSH")
        // default to `~/.oh-my-bash`
        .unwrap_or(
            HOME_DIR
                .join(".oh-my-bash")
                .to_str()
                .expect("should be UTF-8 encoded")
                .to_string(),
        )
        .require()?;

    print_separator("oh-my-bash");

    let mut update_script = oh_my_bash;
    update_script.push_str("/tools/upgrade.sh");

    ctx.run_type().execute("bash").arg(update_script).status_checked()
}

pub fn run_oh_my_fish(ctx: &ExecutionContext) -> Result<()> {
    let fish = require("fish")?;
    HOME_DIR.join(".local/share/omf/pkg/omf/functions/omf.fish").require()?;

    print_separator("oh-my-fish");

    ctx.run_type().execute(fish).args(["-c", "omf update"]).status_checked()
}

pub fn run_pkgin(ctx: &ExecutionContext) -> Result<()> {
    let pkgin = require("pkgin")?;
    let sudo = require_option(ctx.sudo().as_ref(), REQUIRE_SUDO.to_string())?;

    print_separator("Pkgin");

    let mut command = ctx.run_type().execute(sudo);
    command.arg(&pkgin).arg("update");
    if ctx.config().yes(Step::Pkgin) {
        command.arg("-y");
    }
    command.status_checked()?;

    let mut command = ctx.run_type().execute(sudo);
    command.arg(&pkgin).arg("upgrade");
    if ctx.config().yes(Step::Pkgin) {
        command.arg("-y");
    }
    command.status_checked()
}

pub fn run_fish_plug(ctx: &ExecutionContext) -> Result<()> {
    let fish = require("fish")?;
    HOME_DIR
        .join(".local/share/fish/plug/kidonng/fish-plug/functions/plug.fish")
        .require()?;

    print_separator("fish-plug");

    ctx.run_type()
        .execute(fish)
        .args(["-c", "plug update"])
        .status_checked()
}

/// Upgrades `fundle` and `fundle` plugins.
///
/// `fundle` is a package manager for the Fish shell.
///
/// See: <https://github.com/danhper/fundle>
pub fn run_fundle(ctx: &ExecutionContext) -> Result<()> {
    let fish = require("fish")?;
    HOME_DIR.join(".config/fish/fundle").require()?;

    print_separator("fundle");

    ctx.run_type()
        .execute(fish)
        .args(["-c", "fundle self-update && fundle update"])
        .status_checked()
}

#[cfg(not(any(target_os = "android", target_os = "macos")))]
pub fn upgrade_gnome_extensions(ctx: &ExecutionContext) -> Result<()> {
    let gdbus = require("gdbus")?;
    require_option(
        var("XDG_CURRENT_DESKTOP").ok().filter(|p| p.contains("GNOME")),
        "Desktop doest not appear to be gnome".to_string(),
    )?;
    let output = Command::new("gdbus")
        .args([
            "call",
            "--session",
            "--dest",
            "org.freedesktop.DBus",
            "--object-path",
            "/org/freedesktop/DBus",
            "--method",
            "org.freedesktop.DBus.ListActivatableNames",
        ])
        .output_checked_utf8()?;

    debug!("Checking for gnome extensions: {}", output);
    if !output.stdout.contains("org.gnome.Shell.Extensions") {
        return Err(SkipStep(String::from("Gnome shell extensions are unregistered in DBus")).into());
    }

    print_separator("Gnome Shell extensions");

    ctx.run_type()
        .execute(gdbus)
        .args([
            "call",
            "--session",
            "--dest",
            "org.gnome.Shell.Extensions",
            "--object-path",
            "/org/gnome/Shell/Extensions",
            "--method",
            "org.gnome.Shell.Extensions.CheckForUpdates",
        ])
        .status_checked()
}

#[cfg(any(target_os = "linux", target_os = "macos"))]
pub fn run_brew_formula(ctx: &ExecutionContext, variant: BrewVariant) -> Result<()> {
    #[allow(unused_variables)]
    let binary_name = require(variant.binary_name())?;

    #[cfg(target_os = "macos")]
    {
        if variant.is_path() && !BrewVariant::is_macos_custom(binary_name) {
            return Err(SkipStep("Not a custom brew for macOS".to_string()).into());
        }
    }

    print_separator(variant.step_title());
    let run_type = ctx.run_type();

    variant.execute(run_type).arg("update").status_checked()?;
    variant
        .execute(run_type)
        .args(["upgrade", "--formula"])
        .status_checked()?;

    if ctx.config().cleanup() {
        variant.execute(run_type).arg("cleanup").status_checked()?;
    }

    if ctx.config().brew_autoremove() {
        variant.execute(run_type).arg("autoremove").status_checked()?;
    }

    Ok(())
}

#[cfg(target_os = "macos")]
pub fn run_brew_cask(ctx: &ExecutionContext, variant: BrewVariant) -> Result<()> {
    let binary_name = require(variant.binary_name())?;
    if variant.is_path() && !BrewVariant::is_macos_custom(binary_name) {
        return Err(SkipStep("Not a custom brew for macOS".to_string()).into());
    }
    print_separator(format!("{} - Cask", variant.step_title()));
    let run_type = ctx.run_type();

    let cask_upgrade_exists = variant
        .execute(RunType::Wet)
        .args(["--repository", "buo/cask-upgrade"])
        .output_checked_utf8()
        .map(|p| Path::new(p.stdout.trim()).exists())?;

    let mut brew_args = vec![];

    if cask_upgrade_exists {
        brew_args.extend(["cu", "-y"]);
        if ctx.config().brew_cask_greedy() {
            brew_args.push("-a");
        }
    } else {
        brew_args.extend(["upgrade", "--cask"]);
        if ctx.config().brew_cask_greedy() {
            brew_args.push("--greedy");
        }
    }

    variant.execute(run_type).args(&brew_args).status_checked()?;

    if ctx.config().cleanup() {
        variant.execute(run_type).arg("cleanup").status_checked()?;
    }

    Ok(())
}

pub fn run_guix(ctx: &ExecutionContext) -> Result<()> {
    let guix = require("guix")?;

    let run_type = ctx.run_type();

    let output = Command::new(&guix).arg("pull").output_checked_utf8();
    debug!("guix pull output: {:?}", output);
    let should_upgrade = output.is_ok();
    debug!("Can Upgrade Guix: {:?}", should_upgrade);

    print_separator("Guix");

    if should_upgrade {
        return run_type.execute(&guix).args(["package", "-u"]).status_checked();
    }
    Err(SkipStep(String::from("Guix Pull Failed, Skipping")).into())
}

pub fn run_nix(ctx: &ExecutionContext) -> Result<()> {
    let nix = require("nix")?;
    let nix_channel = require("nix-channel")?;
    let nix_env = require("nix-env")?;
    // TODO: Is None possible here?
    let profile_path = match home::home_dir() {
        Some(home) => Path::new(&home).join(".nix-profile"),
        None => Path::new("/nix/var/nix/profiles/per-user/default").into(),
    };
    debug!("nix profile: {:?}", profile_path);
    let manifest_json_path = profile_path.join("manifest.json");

    print_separator("Nix");

    #[cfg(target_os = "macos")]
    {
        if require("darwin-rebuild").is_ok() {
            return Err(SkipStep(String::from(
                "Nix-darwin on macOS must be upgraded via darwin-rebuild switch",
            ))
            .into());
        }
    }

    let run_type = ctx.run_type();
    run_type.execute(nix_channel).arg("--update").status_checked()?;

    if Path::new(&manifest_json_path).exists() {
        run_type
            .execute(nix)
            .args(nix_args())
            .arg("profile")
            .arg("upgrade")
            .arg(".*")
            .arg("--verbose")
            .status_checked()
    } else {
        let mut command = run_type.execute(nix_env);
        command.arg("--upgrade");
        if let Some(args) = ctx.config().nix_env_arguments() {
            command.args(args.split_whitespace());
        };
        command.status_checked()
    }
}

pub fn run_nix_self_upgrade(ctx: &ExecutionContext) -> Result<()> {
    let nix = require("nix")?;

    // Should we attempt to upgrade Nix with `nix upgrade-nix`?
    #[allow(unused_mut)]
    let mut should_self_upgrade = cfg!(target_os = "macos");

    #[cfg(target_os = "linux")]
    {
        // We can't use `nix upgrade-nix` on NixOS.
        if let Ok(Distribution::NixOS) = Distribution::detect() {
            should_self_upgrade = false;
        }
    }

    if !should_self_upgrade {
        return Err(SkipStep(String::from(
            "`nix upgrade-nix` can only be used on macOS or non-NixOS Linux",
        ))
        .into());
    }

    if nix_profile_dir(&nix)?.is_none() {
        return Err(SkipStep(String::from(
            "`nix upgrade-nix` cannot be run when Nix is installed in a profile",
        ))
        .into());
    }

    print_separator("Nix (self-upgrade)");

    let multi_user = fs::metadata(&nix)?.uid() == 0;
    debug!("Multi user nix: {}", multi_user);

    let nix_args = nix_args();
    if multi_user {
        ctx.execute_elevated(&nix, true)?
            .args(nix_args)
            .arg("upgrade-nix")
            .status_checked()
    } else {
        ctx.run_type()
            .execute(&nix)
            .args(nix_args)
            .arg("upgrade-nix")
            .status_checked()
    }
}

/// If we try to `nix upgrade-nix` but Nix is installed with `nix profile`, we'll get a `does not
/// appear to be part of a Nix profile` error.
///
/// We duplicate some of the `nix` logic here to avoid this.
/// See: <https://github.com/NixOS/nix/blob/f0180487a0e4c0091b46cb1469c44144f5400240/src/nix/upgrade-nix.cc#L102-L139>
///
/// See: <https://github.com/NixOS/nix/issues/5473>
fn nix_profile_dir(nix: &Path) -> Result<Option<PathBuf>> {
    // NOTE: `nix` uses the location of the `nix-env` binary for this but we're using the `nix`
    // binary; should be the same.
    let nix_bin_dir = nix.parent();
    if nix_bin_dir.and_then(|p| p.file_name()) != Some(OsStr::new("bin")) {
        debug!("Nix is not installed in a `bin` directory: {nix_bin_dir:?}");
        return Ok(None);
    }

    let nix_dir = nix_bin_dir
        .and_then(|bin_dir| bin_dir.parent())
        .ok_or_else(|| eyre!("Unable to find Nix install directory from Nix binary {nix:?}"))?;

    debug!("Found Nix in {nix_dir:?}");

    let mut profile_dir = nix_dir.to_path_buf();
    while profile_dir.is_symlink() {
        profile_dir = profile_dir
            .parent()
            .ok_or_else(|| eyre!("Path has no parent: {profile_dir:?}"))?
            .join(
                profile_dir
                    .read_link()
                    .wrap_err_with(|| format!("Failed to read symlink {profile_dir:?}"))?,
            );

        // NOTE: `nix` uses a hand-rolled canonicalize function, Rust just uses `realpath`.
        if profile_dir
            .canonicalize()
            .wrap_err_with(|| format!("Failed to canonicalize {profile_dir:?}"))?
            .components()
            .any(|component| component == Component::Normal(OsStr::new("profiles")))
        {
            break;
        }
    }

    debug!("Found Nix profile {profile_dir:?}");

    let user_env = profile_dir
        .canonicalize()
        .wrap_err_with(|| format!("Failed to canonicalize {profile_dir:?}"))?;

    Ok(
        if user_env
            .file_name()
            .and_then(|name| name.to_str())
            .map(|name| name.ends_with("user-environment"))
            .unwrap_or(false)
        {
            Some(profile_dir)
        } else {
            None
        },
    )
}

fn nix_args() -> [&'static str; 2] {
    ["--extra-experimental-features", "nix-command"]
}

pub fn run_yadm(ctx: &ExecutionContext) -> Result<()> {
    let yadm = require("yadm")?;

    print_separator("yadm");

    ctx.run_type().execute(yadm).arg("pull").status_checked()
}

pub fn run_asdf(ctx: &ExecutionContext) -> Result<()> {
    let asdf = require("asdf")?;

    print_separator("asdf");
    ctx.run_type()
        .execute(&asdf)
        .arg("update")
        .status_checked_with_codes(&[42])?;

    ctx.run_type()
        .execute(&asdf)
        .args(["plugin", "update", "--all"])
        .status_checked()
}

pub fn run_home_manager(ctx: &ExecutionContext) -> Result<()> {
    let home_manager = require("home-manager")?;

    print_separator("home-manager");

    let mut cmd = ctx.run_type().execute(home_manager);
    cmd.arg("switch");

    if let Some(extra_args) = ctx.config().home_manager() {
        cmd.args(extra_args);
    }

    cmd.status_checked()
}

pub fn run_tldr(ctx: &ExecutionContext) -> Result<()> {
    let tldr = require("tldr")?;

    print_separator("TLDR");
    ctx.run_type().execute(tldr).arg("--update").status_checked()
}

pub fn run_pearl(ctx: &ExecutionContext) -> Result<()> {
    let pearl = require("pearl")?;
    print_separator("pearl");

    ctx.run_type().execute(pearl).arg("update").status_checked()
}

pub fn run_sdkman(ctx: &ExecutionContext) -> Result<()> {
    let bash = require("bash")?;

    let sdkman_init_path = var("SDKMAN_DIR")
        .map(PathBuf::from)
        .unwrap_or_else(|_| HOME_DIR.join(".sdkman"))
        .join("bin")
        .join("sdkman-init.sh")
        .require()
        .map(|p| format!("{}", &p.display()))?;

    print_separator("SDKMAN!");

    let sdkman_config_path = var("SDKMAN_DIR")
        .map(PathBuf::from)
        .unwrap_or_else(|_| HOME_DIR.join(".sdkman"))
        .join("etc")
        .join("config")
        .require()?;

    let sdkman_config = Ini::load_from_file(sdkman_config_path)?;
    let selfupdate_enabled = sdkman_config
        .general_section()
        .get("sdkman_selfupdate_feature")
        .unwrap_or("false");

    if selfupdate_enabled == "true" {
        let cmd_selfupdate = format!("source {} && sdk selfupdate", &sdkman_init_path);
        ctx.run_type()
            .execute(&bash)
            .args(["-c", cmd_selfupdate.as_str()])
            .status_checked()?;
    }

    let cmd_update = format!("source {} && sdk update", &sdkman_init_path);
    ctx.run_type()
        .execute(&bash)
        .args(["-c", cmd_update.as_str()])
        .status_checked()?;

    let cmd_upgrade = format!("source {} && sdk upgrade", &sdkman_init_path);
    ctx.run_type()
        .execute(&bash)
        .args(["-c", cmd_upgrade.as_str()])
        .status_checked()?;

    if ctx.config().cleanup() {
        let cmd_flush_archives = format!("source {} && sdk flush archives", &sdkman_init_path);
        ctx.run_type()
            .execute(&bash)
            .args(["-c", cmd_flush_archives.as_str()])
            .status_checked()?;

        let cmd_flush_temp = format!("source {} && sdk flush temp", &sdkman_init_path);
        ctx.run_type()
            .execute(&bash)
            .args(["-c", cmd_flush_temp.as_str()])
            .status_checked()?;
    }

    Ok(())
}

pub fn run_bun(ctx: &ExecutionContext) -> Result<()> {
    let bun = require("bun")?;

    print_separator("Bun");

    ctx.run_type().execute(bun).arg("upgrade").status_checked()
}

pub fn run_bun_packages(ctx: &ExecutionContext) -> Result<()> {
    let bun = require("bun")?;

    print_separator("Bun Packages");

    if !HOME_DIR.join(".bun/install/global/package.json").exists() {
        println!("No global packages installed");
        return Ok(());
    }

    ctx.run_type().execute(bun).args(["-g", "update"]).status_checked()
}

/// Update dotfiles with `rcm(7)`.
///
/// See: <https://github.com/thoughtbot/rcm>
pub fn run_rcm(ctx: &ExecutionContext) -> Result<()> {
    let rcup = require("rcup")?;

    print_separator("rcm");
    ctx.run_type().execute(rcup).arg("-v").status_checked()
}

pub fn run_maza(ctx: &ExecutionContext) -> Result<()> {
    let maza = require("maza")?;

    print_separator("maza");
    ctx.run_type().execute(maza).arg("update").status_checked()
}

pub fn reboot() -> Result<()> {
    print!("Rebooting...");
    Command::new("sudo").arg("reboot").status_checked()
}
