#!/usr/bin/env bash
set -euo pipefail

# ====== CONFIG ======
DOTFILES_DIR="${DOTFILES_DIR:-$HOME/repos/dotfiles}"
DOTFILES_GIT_URL="${DOTFILES_GIT_URL:-}"  # ex: git@github.com:TON_USER/dotfiles.git
STOW_PACKAGES_DEFAULT=("zsh" "tmux" "nvim" "hypr" "hypridle" "waybar" "alacritty")

INSTALL_FONTS="${INSTALL_FONTS:-1}"      # 1 = install nerd font, 0 = skip
SET_DEFAULT_SHELL="${SET_DEFAULT_SHELL:-1}" # 1 = chsh to zsh, 0 = skip

# ====== HELPERS ======
log() { printf "\n\033[1m==>\033[0m %s\n" "$*"; }
warn() { printf "\033[33mWARN:\033[0m %s\n" "$*" >&2; }
die() { printf "\033[31mERR:\033[0m %s\n" "$*" >&2; exit 1; }

have() { command -v "$1" >/dev/null 2>&1; }

require_sudo() {
  if [ "${EUID:-$(id -u)}" -ne 0 ]; then
    if ! have sudo; then die "sudo is required"; fi
  fi
}

sudo_run() {
  if [ "${EUID:-$(id -u)}" -eq 0 ]; then
    "$@"
  else
    sudo "$@"
  fi
}

# ====== OS CHECK ======
if [ ! -f /etc/os-release ]; then
  die "Unsupported OS (no /etc/os-release). This script targets Debian/Ubuntu."
fi

. /etc/os-release
case "${ID:-}" in
  debian|ubuntu|linuxmint|pop)
    ;;
  *)
    warn "OS ID=${ID:-unknown}. Script is written for Debian/Ubuntu; proceeding anyway."
    ;;
esac

# ====== APT PACKAGES ======
log "Installing base packages (git, stow, zsh, tmux, neovim, etc.)"
require_sudo
sudo_run apt update
sudo_run apt install -y \
  git curl ca-certificates stow \
  zsh tmux neovim \
  ripgrep fd-find \
  unzip zip tar \
  fontconfig

# Optional: tools often needed by nvim plugins (treesitter, etc.)
sudo_run apt install -y build-essential || true

# Hypr ecosystem (availability depends on distro/repo)
# We try, but do not fail if packages aren't found.
log "Trying to install Hyprland ecosystem packages (best effort)"
sudo_run apt install -y hyprland hypridle waybar alacritty 2>/dev/null || true

# ====== DOTFILES CLONE (OPTIONAL) ======
if [ ! -d "$DOTFILES_DIR/.git" ]; then
  if [ -n "$DOTFILES_GIT_URL" ]; then
    log "Cloning dotfiles repo into: $DOTFILES_DIR"
    mkdir -p "$(dirname "$DOTFILES_DIR")"
    git clone "$DOTFILES_GIT_URL" "$DOTFILES_DIR"
  else
    warn "DOTFILES_DIR has no .git and DOTFILES_GIT_URL is empty."
    warn "Skipping clone. (Set DOTFILES_GIT_URL env var to auto-clone.)"
  fi
else
  log "Dotfiles repo already present: $DOTFILES_DIR"
fi

# ====== OH-MY-ZSH ======
if [ ! -d "$HOME/.oh-my-zsh" ]; then
  log "Installing Oh My Zsh"
  # Unattended install: does not launch zsh at end
  RUNZSH=no CHSH=no KEEP_ZSHRC=yes \
    sh -c "$(curl -fsSL https://raw.githubusercontent.com/ohmyzsh/ohmyzsh/master/tools/install.sh)"
else
  log "Oh My Zsh already installed"
fi

# ====== POWERLEVEL10K + PLUGINS ======
ZSH_CUSTOM="${ZSH_CUSTOM:-$HOME/.oh-my-zsh/custom}"

log "Installing Powerlevel10k theme + useful plugins"
mkdir -p "$ZSH_CUSTOM/themes" "$ZSH_CUSTOM/plugins"

if [ ! -d "$ZSH_CUSTOM/themes/powerlevel10k" ]; then
  git clone --depth=1 https://github.com/romkatv/powerlevel10k.git \
    "$ZSH_CUSTOM/themes/powerlevel10k"
else
  log "powerlevel10k already present"
fi

if [ ! -d "$ZSH_CUSTOM/plugins/zsh-autosuggestions" ]; then
  git clone --depth=1 https://github.com/zsh-users/zsh-autosuggestions \
    "$ZSH_CUSTOM/plugins/zsh-autosuggestions"
else
  log "zsh-autosuggestions already present"
fi

if [ ! -d "$ZSH_CUSTOM/plugins/zsh-syntax-highlighting" ]; then
  git clone --depth=1 https://github.com/zsh-users/zsh-syntax-highlighting \
    "$ZSH_CUSTOM/plugins/zsh-syntax-highlighting"
else
  log "zsh-syntax-highlighting already present"
fi

# ====== NERD FONT (FOR P10K) ======
if [ "$INSTALL_FONTS" = "1" ]; then
  log "Installing Meslo Nerd Font (for Powerlevel10k) (best effort)"
  FONT_DIR="$HOME/.local/share/fonts"
  mkdir -p "$FONT_DIR"

  # Meslo Nerd Font (p10k recommended) - download 4 variants
  # If this fails (no internet), it won't abort the script.
  curl -fsSL -o "$FONT_DIR/MesloLGS NF Regular.ttf" \
    "https://github.com/ryanoasis/nerd-fonts/raw/master/patched-fonts/Meslo/L/Regular/MesloLGSNerdFont-Regular.ttf" || true
  curl -fsSL -o "$FONT_DIR/MesloLGS NF Bold.ttf" \
    "https://github.com/ryanoasis/nerd-fonts/raw/master/patched-fonts/Meslo/L/Bold/MesloLGSNerdFont-Bold.ttf" || true
  curl -fsSL -o "$FONT_DIR/MesloLGS NF Italic.ttf" \
    "https://github.com/ryanoasis/nerd-fonts/raw/master/patched-fonts/Meslo/L/Italic/MesloLGSNerdFont-Italic.ttf" || true
  curl -fsSL -o "$FONT_DIR/MesloLGS NF Bold Italic.ttf" \
    "https://github.com/ryanoasis/nerd-fonts/raw/master/patched-fonts/Meslo/L/Bold-Italic/MesloLGSNerdFont-BoldItalic.ttf" || true

  if have fc-cache; then
    fc-cache -f >/dev/null 2>&1 || true
  fi
else
  log "Skipping font installation (INSTALL_FONTS=0)"
fi

# ====== STOW APPLY ======
if [ -d "$DOTFILES_DIR" ]; then
  log "Applying stow packages into \$HOME (target=~)"
  cd "$DOTFILES_DIR"

  # Only stow packages that exist as directories
  stow_args=()
  for pkg in "${STOW_PACKAGES_DEFAULT[@]}"; do
    if [ -d "$pkg" ]; then
      stow_args+=("$pkg")
    else
      warn "Package dir missing, skipping: $pkg"
    fi
  done

  if [ "${#stow_args[@]}" -eq 0 ]; then
    warn "No stow package dirs found in $DOTFILES_DIR. Nothing to apply."
  else
    # Use verbose so you see what happened
    stow -v -t "$HOME" "${stow_args[@]}"
  fi
else
  warn "DOTFILES_DIR not found: $DOTFILES_DIR (skipping stow apply)"
fi

# ====== DEFAULT SHELL ======
if [ "$SET_DEFAULT_SHELL" = "1" ]; then
  if have zsh; then
    log "Setting default shell to zsh (may prompt for password)"
    # Ensure zsh is in /etc/shells
    if ! grep -q "$(command -v zsh)" /etc/shells 2>/dev/null; then
      warn "zsh not listed in /etc/shells; attempting to add (requires sudo)"
      require_sudo
      echo "$(command -v zsh)" | sudo_run tee -a /etc/shells >/dev/null
    fi
    chsh -s "$(command -v zsh)" "$USER" || true
  else
    warn "zsh not found; cannot set default shell"
  fi
else
  log "Skipping default shell change (SET_DEFAULT_SHELL=0)"
fi

log "Bootstrap complete."
log "Next steps:"
echo "  - Open a new terminal (or log out/in) to use zsh."
echo "  - If p10k prompts, run: p10k configure"
echo "  - If Hypr/Waybar are missing, you may need distro-specific repos (not always in apt)."