#!/bin/bash
set -euo pipefail

# ====================== Flags ======================
WITH_TIDE=0
KEEP_PROMPT=0
REMOVE_TIDE=0
VERBOSE=0
NO_PLUGINS=0
UPDATE_MODE="prompt"   # prompt | yes | no

while [[ $# -gt 0 ]]; do
  case "$1" in
    --with-tide)       WITH_TIDE=1 ;;
    --keep-prompt)     KEEP_PROMPT=1 ;;
    --remove-tide)     REMOVE_TIDE=1 ;;
    --verbose)         VERBOSE=1 ;;
    --no-plugins)      NO_PLUGINS=1 ;;
    --update-check)    UPDATE_MODE="yes" ;;
    --no-update-check) UPDATE_MODE="no" ;;
    --) shift; break ;;
    *) echo "Unknown option: $1"; exit 1 ;;
  esac
  shift
done

# Default plugin set (safe; no prompt change)
PLUGINS=("jethrokuan/z" "jorgebucaran/nvm.fish")
[[ $WITH_TIDE -eq 1 ]] && PLUGINS+=("ilancosman/tide")

# ====================== UI Helpers ======================
log() { echo -e "• $*"; }
ok()  { echo -e "✓ $*"; }
warn(){ echo -e "! $*" >&2; }

padright() { printf "%-28s" "$1"; }
draw_bar() {
  local cur="$1" total="$2" label="$3" width=40
  (( total == 0 )) && total=1
  local percent=$(( cur * 100 / total ))
  (( percent > 100 )) && percent=100
  local filled=$(( width * cur / total ))
  (( filled > width )) && filled=$width
  local empty=$(( width - filled ))
  printf "\rInstalling: %s [%s%s] %3d%%" \
    "$(padright "$label")" \
    "$(printf '%0.s#' $(seq 1 $filled))" \
    "$(printf '%0.s.' $(seq 1 $empty))" \
    "$percent"
}

prompt_yn_tty() {
  local prompt="${1:-Proceed (y/N): }"
  local d="${2:-N}" ans=""
  if [ -r /dev/tty ] && [ -w /dev/tty ]; then
    read -r -p "$prompt" ans </dev/tty || true
    [[ ${ans:-$d} =~ ^[Yy]$ ]]
  else
    [[ "$d" =~ ^[Yy]$ ]]
  fi
}

# ====================== Platform Detect ======================
detect_platform() {
  if [[ "$OSTYPE" == "darwin"* ]]; then
    OS="macos"; PKG_MGR="brew"
    if ! command -v brew &>/dev/null; then
      log "Installing Homebrew…"
      /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
      echo 'eval "$(/opt/homebrew/bin/brew shellenv)"' >> ~/.zprofile
      eval "$(/opt/homebrew/bin/brew shellenv)"
      ok "Homebrew installed"
    fi
  elif command -v apt &>/dev/null; then OS="debian"; PKG_MGR="apt"
  elif command -v dnf &>/dev/null; then OS="rhel";   PKG_MGR="dnf"
  elif command -v yum &>/dev/null; then OS="rhel";   PKG_MGR="yum"
  elif command -v pacman &>/dev/null; then OS="arch"; PKG_MGR="pacman"
  else warn "Unsupported platform"; exit 1; fi
  ok "Detected ${OS} (${PKG_MGR})"
}

# ====================== Debian repo/key ======================
install_gpg_if_needed() {
  if [[ "${OS}" == "debian" ]] && ! command -v gpg &>/dev/null; then
    log "Installing gnupg…"
    sudo apt update && sudo apt install -y gnupg
    ok "gnupg installed"
  fi
}
add_fish_repo_debian() {
  log "Adding Fish repo (Debian)…"
  echo 'deb http://download.opensuse.org/repositories/shells:/fish:/release:/4/Debian_12/ /' \
    | sudo tee /etc/apt/sources.list.d/fish.list >/dev/null
  curl -fsSL https://download.opensuse.org/repositories/shells:fish:release:4/Debian_12/Release.key \
    | gpg --dearmor | sudo tee /etc/apt/trusted.gpg.d/fish.gpg >/dev/null
  sudo apt update
  ok "Repo added"
}

# ====================== Fish install/update ======================
install_fish() {
  log "Installing Fish…"
  case "$OS" in
    debian) add_fish_repo_debian; sudo apt install -y fish ;;
    rhel)   sudo "$PKG_MGR" install -y fish ;;
    arch)   sudo pacman -Sy --noconfirm fish ;;
    macos)  brew install fish ;;
  esac
  ok "Fish installed"
}

should_check_updates() {
  case "$UPDATE_MODE" in
    yes) return 0 ;;
    no)  return 1 ;;
    prompt)
      prompt_yn_tty "Check for Fish updates (may run a repo refresh)? (y/N): " "N"
      return $? ;;
  esac
}

update_fish_if_available() {
  log "Checking Fish updates…"
  case "$PKG_MGR" in
    apt)
      if should_check_updates; then
        sudo apt update
        apt list --upgradable 2>/dev/null | grep -q "^fish/" && sudo apt install -y fish || true
      else
        ok "Skipped update check"
      fi
      ;;
    dnf|yum)
      if should_check_updates; then
        sudo "$PKG_MGR" check-update || true
        "$PKG_MGR" list updates | grep -q "^fish" && sudo "$PKG_MGR" update -y fish || true
      else
        ok "Skipped update check"
      fi
      ;;
    pacman)
      if should_check_updates; then
        sudo pacman -Sy --noconfirm
        pacman -Qu | grep -q "^fish" && sudo pacman -S --noconfirm fish || true
      else
        ok "Skipped update check"
      fi
      ;;
    brew)
      if should_check_updates; then
        brew update
        brew outdated | grep -q "^fish" && brew upgrade fish || true
      else
        ok "Skipped update check"
      fi
      ;;
  esac
  ok "Fish up to date"
}

# ====================== Fisher & Plugins ======================
ensure_fisher() {
  if fish -c 'functions -q fisher' </dev/null >/dev/null 2>&1; then
    ok "Fisher already present"
  else
    log "Installing Fisher…"
    fish -c 'curl -sL https://git.io/fisher | source && fisher install jorgebucaran/fisher' </dev/null >/dev/null 2>&1
    ok "Fisher installed"
  fi
}

install_plugins() {
  [[ $NO_PLUGINS -eq 1 ]] && { ok "Skipping plugins (per flag)"; return; }

  # Current installed plugins
  local installed
  installed="$(fish -c 'fisher list' </dev/null 2>/dev/null || true)"

  # Determine missing plugins
  local missing=()
  for p in "${PLUGINS[@]}"; do
    if ! grep -Fxq "$p" <<<"$installed"; then
      missing+=("$p")
    fi
  done

  # Nothing to do?
  if [[ ${#missing[@]} -eq 0 ]]; then
    ok "All requested plugins already installed"
  else
    if [[ $VERBOSE -eq 1 ]]; then
      for p in "${missing[@]}"; do
        echo "Installing (verbose): $p"
        fish -c "fisher install $p" </dev/null
      done
      ok "Plugins installed"
    else
      local total=${#missing[@]}
      local i=0
      for p in "${missing[@]}"; do
        i=$((i+1))
        draw_bar "$((i-1))" "$total" "$p"
        ( fish -c "fisher install $p" </dev/null >/dev/null 2>&1 ) &
        pid=$!
        while kill -0 "$pid" 2>/dev/null; do
          draw_bar "$((i-1))" "$total" "$p"
          sleep 0.08
        done
        draw_bar "$i" "$total" "$p"
      done
      echo
      ok "Plugins installed"
    fi
  fi

  # If Tide installed but user wants to keep default prompt
  if [[ $WITH_TIDE -eq 1 && $KEEP_PROMPT -eq 1 ]]; then
    log "Keeping default Fish prompt (disabling Tide init)…"
    rm -f ~/.config/fish/functions/fish_prompt.fish \
          ~/.config/fish/conf.d/_tide_init.fish 2>/dev/null || true
    ok "Default prompt preserved"
  fi
}

remove_tide_if_requested() {
  [[ $REMOVE_TIDE -eq 0 ]] && return

  ensure_fisher  # make sure fisher exists so removal works

  # Only remove if installed
  if fish -c 'fisher list' </dev/null 2>/dev/null | grep -Fxq "ilancosman/tide"; then
    log "Removing Tide…"
    if [[ $VERBOSE -eq 1 ]]; then
      fish -c "fisher remove ilancosman/tide" </dev/null
    else
      fish -c "fisher remove ilancosman/tide" </dev/null >/dev/null 2>&1
    fi
  fi

  # Clean any prompt overrides
  rm -f ~/.config/fish/functions/fish_prompt.fish \
        ~/.config/fish/conf.d/_tide_init.fish 2>/dev/null || true
  ok "Tide removed and default prompt restored"
}

# ====================== Main ======================
detect_platform

if command -v fish &>/dev/null; then
  ok "Fish already installed"
  update_fish_if_available
else
  install_gpg_if_needed
  install_fish
fi

ensure_fisher
install_plugins
remove_tide_if_requested

ok "Fish + Fisher + plugins ready on ${OS}"