#!/usr/bin/env bash
# =============================================================================
# pimp-my-termux — AI Coding Agents Installer
# Installs: Claude Code, Gemini CLI, GitHub Copilot CLI, Aider
#
# Usage (in Termux):
#   bash install-ai-agents.sh
#   bash install-ai-agents.sh --skip-update   # skip pkg update (faster re-runs)
# =============================================================================

# --- Colors ------------------------------------------------------------------
R='\033[0;31m'  G='\033[0;32m'  Y='\033[1;33m'
B='\033[0;34m'  C='\033[0;36m'  M='\033[0;35m'
BOLD='\033[1m'  DIM='\033[2m'   NC='\033[0m'

# --- Helpers -----------------------------------------------------------------
info()    { echo -e "${C}[·]${NC} $*"; }
success() { echo -e "${G}[✓]${NC} $*"; }
warn()    { echo -e "${Y}[!]${NC} $*"; }
error()   { echo -e "${R}[✗]${NC} $*"; }
header()  { echo -e "\n${BOLD}${B}━━━ $* ${NC}"; }
step()    { echo -e "    ${DIM}→${NC} $*"; }

FAILED_TOOLS=()
SKIP_UPDATE=false
[[ "${1:-}" == "--skip-update" ]] && SKIP_UPDATE=true

# --- Banner ------------------------------------------------------------------
print_banner() {
  echo -e "${M}${BOLD}"
  echo "  ╔═══════════════════════════════════════════╗"
  echo "  ║       pimp-my-termux · AI Agents          ║"
  echo "  ║   Claude · Gemini · Copilot · Aider       ║"
  echo "  ╚═══════════════════════════════════════════╝"
  echo -e "${NC}"
}

# --- Termux guard ------------------------------------------------------------
check_termux() {
  if [[ -z "${PREFIX:-}" || ! -d "/data/data/com.termux" ]]; then
    error "This script must run inside Termux on Android."
    exit 1
  fi
  success "Termux detected  (PREFIX=$PREFIX)"
}

# --- Storage permission ------------------------------------------------------
setup_storage() {
  if [[ ! -d "$HOME/storage" ]]; then
    info "Requesting storage permission (termux-setup-storage)…"
    termux-setup-storage
    sleep 2
  else
    success "Storage already set up"
  fi
}

# --- Package update ----------------------------------------------------------
update_packages() {
  if $SKIP_UPDATE; then
    warn "Skipping package update (--skip-update flag)"
    return
  fi
  info "Updating package lists…"
  pkg update -y && pkg upgrade -y
  success "Packages up to date"
}

# --- Core dependencies -------------------------------------------------------
install_dependencies() {
  header "Core Dependencies"

  local deps=(nodejs-lts git python make clang binutils)

  for dep in "${deps[@]}"; do
    if pkg list-installed 2>/dev/null | grep -q "^${dep}/"; then
      success "$dep already installed"
    else
      info "Installing $dep…"
      if pkg install -y "$dep"; then
        success "$dep installed"
      else
        error "Failed to install $dep — subsequent tools may fail"
      fi
    fi
  done

  # pip upgrade
  info "Upgrading pip…"
  python -m pip install --upgrade pip --quiet
  success "pip upgraded"
}

# --- npm global prefix -------------------------------------------------------
configure_npm() {
  header "npm Configuration"

  # In Termux the default npm global prefix is already $PREFIX, which is
  # writable. Only reconfigure if it looks misconfigured.
  local npm_prefix
  npm_prefix=$(npm config get prefix 2>/dev/null || echo "")

  if [[ "$npm_prefix" == "$PREFIX" ]]; then
    success "npm prefix already correct ($PREFIX)"
  else
    info "Setting npm prefix to \$PREFIX ($PREFIX)…"
    npm config set prefix "$PREFIX"
    success "npm prefix set"
  fi

  # Confirm node/npm versions
  step "node  $(node --version)"
  step "npm   $(npm --version)"
}

# --- Install: Claude Code ----------------------------------------------------
install_claude_code() {
  header "Claude Code CLI"
  info "Installing @anthropic-ai/claude-code…"

  if npm install -g @anthropic-ai/claude-code; then
    success "Claude Code installed  →  $(claude --version 2>/dev/null || echo 'run: claude --version')"
    echo -e "    ${DIM}API key setup:  export ANTHROPIC_API_KEY='sk-ant-…'${NC}"
    echo -e "    ${DIM}Get a key:      https://console.anthropic.com/settings/api-keys${NC}"
  else
    error "Claude Code installation failed"
    FAILED_TOOLS+=("claude-code")
  fi
}

# --- Install: Gemini CLI ------------------------------------------------------
install_gemini_cli() {
  header "Gemini CLI"
  info "Installing @google/gemini-cli…"

  if npm install -g @google/gemini-cli; then
    success "Gemini CLI installed  →  $(gemini --version 2>/dev/null || echo 'run: gemini --version')"
    echo -e "    ${DIM}API key setup:  export GEMINI_API_KEY='AIza…'${NC}"
    echo -e "    ${DIM}Get a key:      https://aistudio.google.com/app/apikey${NC}"
  else
    error "Gemini CLI installation failed"
    FAILED_TOOLS+=("gemini-cli")
  fi
}

# --- Install: GitHub Copilot CLI ---------------------------------------------
install_copilot_cli() {
  header "GitHub Copilot CLI"
  info "Installing @githubnext/github-copilot-cli…"

  if npm install -g @githubnext/github-copilot-cli; then
    success "GitHub Copilot CLI installed"
    echo -e "    ${DIM}Authenticate:   github-copilot-cli auth${NC}"
    echo -e "    ${DIM}Requires:       GitHub account with Copilot subscription${NC}"
    echo -e "    ${DIM}Aliases added after auth:  ?? (shell)  git? (git)  gh? (gh)${NC}"
  else
    error "GitHub Copilot CLI installation failed"
    FAILED_TOOLS+=("copilot-cli")
  fi
}

# --- Install: Aider (replaces Cursor CLI) ------------------------------------
install_aider() {
  header "Aider (AI Pair Programmer)"
  echo -e "  ${Y}Note about Cursor:${NC} Cursor is a desktop IDE (Electron app) with no"
  echo -e "  terminal CLI and cannot run on Android/Termux."
  echo -e "  ${G}Aider${NC} fills that role: it's an open-source AI coding agent that"
  echo -e "  works in your terminal, supports Claude/Gemini/GPT-4 and edits real"
  echo -e "  files with git integration — more powerful for headless use.\n"

  info "Installing aider-chat via pip…"

  # Use pipx if available for cleaner isolation, else pip directly
  if command -v pipx &>/dev/null; then
    if pipx install aider-chat; then
      success "Aider installed via pipx"
    else
      warn "pipx install failed, retrying with pip…"
      pip install --upgrade aider-chat
    fi
  else
    if pip install --upgrade aider-chat; then
      success "Aider installed via pip"
    else
      error "Aider installation failed"
      FAILED_TOOLS+=("aider")
      return
    fi
  fi

  local aider_ver
  aider_ver=$(aider --version 2>/dev/null || echo "unknown")
  success "Aider $aider_ver  →  run: aider --help"
  echo -e "    ${DIM}With Claude:    aider --model claude-sonnet-4-6${NC}"
  echo -e "    ${DIM}With Gemini:    aider --model gemini/gemini-2.5-pro${NC}"
  echo -e "    ${DIM}With GPT-4:     aider --model gpt-4o${NC}"
  echo -e "    ${DIM}Docs:           https://aider.chat${NC}"
}

# --- Shell environment hints -------------------------------------------------
print_env_hints() {
  header "Environment Setup"
  echo -e "  Add these exports to ${BOLD}~/.bashrc${NC} (or ~/.zshrc):\n"

  cat << 'ENVBLOCK'
  # ── AI Coding Agents ──────────────────────────────────────────────
  export ANTHROPIC_API_KEY="sk-ant-YOUR_KEY_HERE"
  export GEMINI_API_KEY="AIzaYOUR_KEY_HERE"
  export OPENAI_API_KEY="sk-YOUR_KEY_HERE"      # optional, for aider/GPT

  # Copilot CLI shell aliases (run once: github-copilot-cli auth)
  eval "$(github-copilot-cli alias -- "$0")"    # adds ?? git? gh? shortcuts
ENVBLOCK

  echo ""
  info "Apply immediately with:  source ~/.bashrc"
}

# --- Summary -----------------------------------------------------------------
print_summary() {
  header "Installation Summary"

  local all_tools=("claude (claude-code)" "gemini (gemini-cli)" "github-copilot-cli" "aider")

  for tool in "${all_tools[@]}"; do
    local bin
    bin=$(echo "$tool" | awk '{print $1}')
    if command -v "$bin" &>/dev/null; then
      success "$tool"
    else
      # check if it was in our failed list
      local label
      label=$(echo "$tool" | sed 's/[()]//g')
      warn "$tool — not found in PATH (may need to reopen Termux)"
    fi
  done

  if [[ ${#FAILED_TOOLS[@]} -gt 0 ]]; then
    echo ""
    error "The following installations encountered errors:"
    for t in "${FAILED_TOOLS[@]}"; do
      echo -e "    ${R}•${NC} $t"
    done
    echo ""
    warn "Try re-running:  bash install-ai-agents.sh --skip-update"
  else
    echo ""
    echo -e "  ${G}${BOLD}All tools installed successfully!${NC}"
  fi

  echo ""
  echo -e "  ${DIM}Reopen Termux or run 'source ~/.bashrc' to refresh PATH.${NC}"
  echo ""
}

# --- Main --------------------------------------------------------------------
main() {
  print_banner
  check_termux
  setup_storage
  update_packages
  install_dependencies
  configure_npm
  install_claude_code
  install_gemini_cli
  install_copilot_cli
  install_aider
  print_env_hints
  print_summary
}

main "$@"