#!/usr/bin/env bash

# Mike's Dotfiles Install Script
# Safe to run multiple times (idempotent).
# Targets both macOS and Linux (Coder devboxes).

set -euo pipefail

# --- Configuration ---
export HOMEBREW_TEMP="/tmp"

# Optional components (default to true)
INSTALL_NODE=${INSTALL_NODE:-true}
INSTALL_PYTHON=${INSTALL_PYTHON:-true}
INSTALL_GO=${INSTALL_GO:-true}
INSTALL_JAVA=${INSTALL_JAVA:-true}

BREW_PACKAGES=(
  git diff-so-fancy btop gh zsh starship stow bat fd jq wget eza
  git-lfs difftastic fzf direnv git-delta zsh-completions
  gemini-cli claude-code zsh-autosuggestions zsh-syntax-highlighting
  zsh-history-substring-search zoxide ripgrep
)

# Only install tmux if not on macOS
[[ "$(uname)" != "Darwin" ]] && BREW_PACKAGES+=(tmux)

# Add optional packages to Homebrew list
[[ "$INSTALL_GO" == "true" ]] && BREW_PACKAGES+=(go)
[[ "$INSTALL_JAVA" == "true" ]] && BREW_PACKAGES+=(openjdk)
[[ "$INSTALL_PYTHON" == "true" ]] && BREW_PACKAGES+=(pyenv)

MAC_CASK_PACKAGES=(iterm2 font-hack-nerd-font)

STOW_PACKAGES=(editorconfig gh git claude cursor starship zsh)

# --- Utilities ---
info() { echo -e "\033[0;34m[INFO]\033[0m $*"; }
warn() { echo -e "\033[0;33m[WARN]\033[0m $*"; }
error() { echo -e "\033[0;31m[ERROR]\033[0m $*"; exit 1; }

OS_TYPE=$(uname)
DOTFILES_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

# --- macOS System Setup ---
if [[ "$OS_TYPE" == "Darwin" ]]; then
  info "Configuring macOS system defaults..."
  defaults write com.apple.finder AppleShowAllFiles YES
  defaults write com.apple.finder ShowPathbar -bool true
  defaults write com.apple.finder ShowStatusBar -bool true
  # Refresh Finder
  killall Finder 2>/dev/null || true
fi

# --- Homebrew Setup ---
if ! command -v brew &> /dev/null; then
  info "Installing Homebrew..."
  NONINTERACTIVE=1 /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
fi

# Initialize Homebrew environment for the current script
if [[ "$OS_TYPE" == "Darwin" ]]; then
  eval "$(/opt/homebrew/bin/brew shellenv)" 2>/dev/null || eval "$(/usr/local/bin/brew shellenv)" 2>/dev/null
  ZSH_PATH="$(brew --prefix)/bin/zsh"
else
  # Linux / Coder
  if [ -d "/home/linuxbrew/.linuxbrew" ]; then
    eval "$(/home/linuxbrew/.linuxbrew/bin/brew shellenv)"
  fi
  ZSH_PATH="/home/linuxbrew/.linuxbrew/bin/zsh"
fi

BREW_BIN=$(command -v brew)

# --- Package Installation ---
info "Installing Homebrew packages..."
$BREW_BIN install "${BREW_PACKAGES[@]}" || warn "Some packages might have failed to install or are already present."

if [[ "$OS_TYPE" == "Darwin" ]]; then
  info "Installing macOS casks..."
  $BREW_BIN install --cask "${MAC_CASK_PACKAGES[@]}" || warn "Some casks might have failed to install."
  
  # Permissions fix for completions
  chmod go-w "$(brew --prefix)/share" 2>/dev/null || true
  chmod -R go-w "$(brew --prefix)/share/zsh" 2>/dev/null || true
fi

# --- Shell Setup ---
info "Setting up Zsh..."

# Add to /etc/shells if missing
if ! grep -q "$ZSH_PATH" /etc/shells; then
  info "Adding $ZSH_PATH to /etc/shells"
  if command -v sudo &> /dev/null; then
    echo "$ZSH_PATH" | sudo tee -a /etc/shells
  else
    warn "Sudo not found, skipping /etc/shells update"
  fi
fi

# Change default shell
CURRENT_LOGIN_SHELL=""
if [[ "$OS_TYPE" == "Darwin" ]]; then
  CURRENT_LOGIN_SHELL=$(dscl . -read "/Users/$USER" UserShell | awk '{print $2}')
else
  CURRENT_LOGIN_SHELL=$(getent passwd "$USER" | cut -d: -f7)
fi

if [[ "$CURRENT_LOGIN_SHELL" != "$ZSH_PATH" ]]; then
  info "Changing default shell to $ZSH_PATH"
  if command -v sudo &> /dev/null; then
    sudo chsh -s "$ZSH_PATH" "$USER" || warn "Failed to change shell with sudo"
  else
    warn "Sudo not found, skipping shell change"
  fi
fi

# Oh My Zsh
if [ ! -d "$HOME/.oh-my-zsh" ]; then
  info "Installing Oh My Zsh..."
  sh -c "$(curl -fsSL https://raw.githubusercontent.com/ohmyzsh/ohmyzsh/master/tools/install.sh)" "" --unattended
fi

# --- Runtime Environments ---
# NVM / Node
if [[ "$INSTALL_NODE" == "true" ]]; then
  info "Configuring NVM..."
  export NVM_DIR="$HOME/.nvm"
  if [ ! -d "$NVM_DIR" ]; then
    info "Installing NVM via official script..."
    curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.40.1/install.sh | bash
  fi

  # Remove incompatible prefix/globalconfig from .npmrc for nvm compatibility
  if [ -f "$HOME/.npmrc" ]; then
    info "Cleaning .npmrc of incompatible settings..."
    if [[ "$OS_TYPE" == "Darwin" ]]; then
      sed -i '' '/^prefix=/d; /^globalconfig=/d' "$HOME/.npmrc"
    else
      sed -i '/^prefix=/d; /^globalconfig=/d' "$HOME/.npmrc"
    fi
  fi

  # shellcheck source=/dev/null
  if [ -s "$NVM_DIR/nvm.sh" ]; then
    source "$NVM_DIR/nvm.sh"
    nvm install --lts
    npm install -g npm@latest
  fi
fi

# Pyenv / Python
if [[ "$INSTALL_PYTHON" == "true" ]] && command -v pyenv &> /dev/null; then
  info "Configuring Pyenv..."
  eval "$(pyenv init -)"
  pyenv install 3.10 -s
  pyenv global 3.10
fi

# FZF Setup
if command -v fzf &> /dev/null; then
  info "Configuring FZF..."
  "$(brew --prefix)/opt/fzf/install" --key-bindings --completion --no-update-rc --no-bash --no-zsh || true
fi

# --- AI Rules Generation ---
generate_rules() {
  local target_dir="$DOTFILES_DIR/$1"
  info "Generating rules in $target_dir"
  mkdir -p "$target_dir"
  # Remove stale symlinks
  find "$target_dir" -type l -delete
  # Create new symlinks
  for rule in "$DOTFILES_DIR/ai-instructions"/*.md; do
    [ -e "$rule" ] || continue
    ln -sf "$rule" "$target_dir/$(basename "$rule")"
  done
}

generate_rules "claude/.claude/rules"
generate_rules "cursor/.cursor/rules"

# --- Stow ---
info "Applying dotfile configurations via Stow..."
for pkg in "${STOW_PACKAGES[@]}"; do
  info "Stowing $pkg..."
  # Detect conflicts and remove non-stow files
  stow --simulate "$pkg" -t "$HOME" -d "$DOTFILES_DIR" 2>&1 | \
    grep -E "(existing target is (not owned by stow|neither a link nor a directory):|over existing target .+ since neither a link)" | \
    awk '/over existing target/ { for(i=1;i<=NF;i++) if($i=="target") { print $(i+1); break } next } /:/ { sub(/.*: /, ""); print }' | \
    while read -r conflict; do
      if [ -n "$conflict" ]; then
        warn "Removing conflict: $HOME/$conflict"
        rm -rf "$HOME/$conflict"
      fi
    done || true
  stow "$pkg" -t "$HOME" -d "$DOTFILES_DIR"
done

# --- Git Local Config ---
info "Configuring machine-specific Git settings..."
GIT_LOCAL_CONFIG="$HOME/.gitconfig_local"
WORK_DIR="$HOME/work"

if [[ "$OS_TYPE" == "Darwin" ]]; then
  GH_PATH="/opt/homebrew/bin/gh"
else
  GH_PATH="/home/linuxbrew/.linuxbrew/bin/gh"
fi

# Set credential helper
git config --file "$GIT_LOCAL_CONFIG" credential."https://github.com".helper "!$GH_PATH auth git-credential"
git config --file "$GIT_LOCAL_CONFIG" credential."https://gist.github.com".helper "!$GH_PATH auth git-credential"

# --- Final Tools & Linux Extras ---
if [[ "$OS_TYPE" == "Linux" ]]; then
  if command -v apt-get &> /dev/null; then
    info "Installing nano via apt..."
    sudo apt-get update -qq && sudo apt-get install -y -qq nano || warn "Failed to install nano"
  fi
  
  # Bash auto-switch to zsh
  if ! grep -q "exec \"$ZSH_PATH\"" "$HOME/.bashrc" 2>/dev/null; then
    info "Adding Zsh auto-switch to .bashrc"
    cat >> "$HOME/.bashrc" <<EOF

# Auto-switch to zsh if available and interactive
if [ -t 1 ] && [ -n "\$PS1" ] && [ "\$BASH" ] && [ -x "$ZSH_PATH" ]; then
    export SHELL="$ZSH_PATH"
    exec "$ZSH_PATH"
fi
EOF
  fi
fi

info "Installation complete! Please restart your terminal or run 'source $HOME/.zshrc'"