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

# ---------------------------------------------------------------------------
# Server CLI Tools — interactive installer
# Clone this repo to any Ubuntu/Debian server and run: ./install.sh
# ---------------------------------------------------------------------------

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
CONFIGS="$SCRIPT_DIR/configs"
BACKUP_DIR="$HOME/.server_cli_tools_bkp/$(date +%Y%m%d-%H%M%S)"

# SSH from Ghostty and other clients forwards TERM values (e.g. xterm-ghostty)
# that remote servers often lack in terminfo — breaks clear/tput and colors.
if ! infocmp "${TERM:-}" &>/dev/null; then
    for _term_fallback in xterm-256color xterm screen dumb; do
        if infocmp "$_term_fallback" &>/dev/null; then
            export TERM="$_term_fallback"
            break
        fi
    done
    unset _term_fallback
fi

# Colors (matching the dotfiles convention)
e_err()  { echo -e "\e[1;31m$1\e[0m"; }
e_info() { echo -e "\e[1;34m$1\e[0m"; }
e_succ() { echo -e "\e[1;32m$1\e[0m"; }
e_warn() { echo -e "\e[1;38;5;208m$1\e[0m"; }

INSTALLED=()
SKIPPED=()

# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------

backup_file() {
    local src="$1"
    if [ -e "$src" ]; then
        local rel="${src#$HOME/}"
        local dest="$BACKUP_DIR/$rel"
        mkdir -p "$(dirname "$dest")"
        cp -a "$src" "$dest"
        e_info "  Backed up $src"
    fi
}

copy_config() {
    local src="$1" dest="$2"
    backup_file "$dest"
    mkdir -p "$(dirname "$dest")"
    cp -a "$src" "$dest"
}

copy_dir() {
    local src="$1" dest="$2"
    if [ -d "$dest" ]; then
        backup_file "$dest"
    fi
    mkdir -p "$dest"
    cp -a "$src"/. "$dest"/
}

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

safe_clear() {
    clear 2>/dev/null || printf '\033[H\033[2J'
}

check_os() {
    if [ ! -f /etc/os-release ]; then
        e_err "Cannot detect OS. This script supports Ubuntu/Debian only."
        exit 1
    fi
    . /etc/os-release
    case "$ID" in
        ubuntu|debian) ;;
        *)
            e_warn "Detected $ID — this script is designed for Ubuntu/Debian."
            e_warn "Package installation may not work. Configs will still be copied."
            ;;
    esac
}

apt_install() {
    local packages=("$@")
    local to_install=()
    for pkg in "${packages[@]}"; do
        if dpkg -s "$pkg" &>/dev/null; then
            e_info "  $pkg is already installed"
        else
            to_install+=("$pkg")
        fi
    done
    if [ ${#to_install[@]} -gt 0 ]; then
        e_info "  Installing: ${to_install[*]}"
        sudo apt-get install -y "${to_install[@]}"
    fi
}

# ---------------------------------------------------------------------------
# Component installers
# ---------------------------------------------------------------------------

install_core_packages() {
    e_info "\n[1/6] Core packages"
    sudo apt-get update -qq

    apt_install curl vim bat fzf htop tmux zsh ripgrep fd-find zoxide

    # bat is installed as 'batcat' on Debian/Ubuntu
    if command_exists batcat && ! command_exists bat; then
        sudo ln -sf /usr/bin/batcat /usr/local/bin/bat
        e_info "  Symlinked batcat -> bat"
    fi

    # eza — not in all distro repos, try apt first, fall back to cargo/binary
    if ! command_exists eza; then
        if apt-cache show eza &>/dev/null; then
            apt_install eza
        else
            e_warn "  eza not in apt repos. Install manually: https://github.com/eza-community/eza"
        fi
    else
        e_info "  eza is already installed"
    fi

    # git-delta
    if ! command_exists delta; then
        if apt-cache show git-delta &>/dev/null; then
            apt_install git-delta
        else
            e_warn "  git-delta not in apt repos. Install from: https://github.com/dandavison/delta/releases"
        fi
    else
        e_info "  delta is already installed"
    fi

    INSTALLED+=("core-packages")
}

install_zsh() {
    e_info "\n[2/6] Zsh + Oh-My-Zsh"

    if ! command_exists zsh; then
        apt_install zsh
    fi

    # Oh-My-Zsh
    if [ ! -d "$HOME/.oh-my-zsh" ]; then
        e_info "  Installing Oh-My-Zsh..."
        RUNZSH=no CHSH=no sh -c "$(curl -fsSL https://raw.githubusercontent.com/ohmyzsh/ohmyzsh/master/tools/install.sh)" "" --unattended
    else
        e_info "  Oh-My-Zsh already installed"
    fi

    # Plugins
    local zsh_custom="${ZSH_CUSTOM:-$HOME/.oh-my-zsh/custom}"

    if [ ! -d "$zsh_custom/plugins/zsh-autosuggestions" ]; then
        e_info "  Cloning zsh-autosuggestions..."
        git clone --quiet https://github.com/zsh-users/zsh-autosuggestions "$zsh_custom/plugins/zsh-autosuggestions"
    else
        e_info "  zsh-autosuggestions already installed"
    fi

    if [ ! -d "$zsh_custom/plugins/zsh-syntax-highlighting" ]; then
        e_info "  Cloning zsh-syntax-highlighting..."
        git clone --quiet https://github.com/zsh-users/zsh-syntax-highlighting.git "$zsh_custom/plugins/zsh-syntax-highlighting"
    else
        e_info "  zsh-syntax-highlighting already installed"
    fi

    # Theme
    mkdir -p "$HOME/.config/zsh"
    copy_config "$CONFIGS/zsh/zhann-elvis.zsh-theme" "$HOME/.config/zsh/zhann-elvis.zsh-theme"
    e_info "  Installed zhann-elvis.zsh-theme"

    # .zshrc
    copy_config "$CONFIGS/zshrc" "$HOME/.zshrc"
    e_info "  Installed .zshrc"

    # Change default shell to zsh (if not already)
    if [ "$(basename "$SHELL")" != "zsh" ]; then
        e_info "  Changing default shell to zsh..."
        if command_exists chsh; then
            chsh -s "$(which zsh)" || e_warn "  chsh failed — change shell manually: chsh -s \$(which zsh)"
        fi
    fi

    INSTALLED+=("zsh")
}

install_aliases() {
    e_info "\n[3/6] Aliases + custom tools"

    copy_dir "$CONFIGS/aliases" "$HOME/.config/aliases"
    chmod +x "$HOME/.config/aliases"/.aliases "$HOME/.config/aliases"/.functions.sh 2>/dev/null || true
    e_info "  Installed aliases to ~/.config/aliases/"

    copy_dir "$CONFIGS/custom_tools" "$HOME/.config/custom_tools"
    chmod +x "$HOME/.config/custom_tools"/*.sh 2>/dev/null || true
    e_info "  Installed custom tools to ~/.config/custom_tools/"

    INSTALLED+=("aliases" "custom-tools")
}

install_terminal_configs() {
    e_info "\n[4/6] Terminal configs (bat)"

    mkdir -p "$HOME/.config/bat"
    copy_config "$CONFIGS/bat/config" "$HOME/.config/bat/config"
    e_info "  Installed bat config (theme: base16)"

    INSTALLED+=("terminal-configs")
}

install_docker() {
    e_info "\n[5/6] Docker"

    sudo apt-get update -qq
    apt_install docker.io

    if command_exists systemctl; then
        sudo systemctl enable --now docker 2>/dev/null \
            || e_warn "  Could not enable docker service — start manually: sudo systemctl start docker"
    fi

    if id -nG "$USER" 2>/dev/null | grep -qw docker; then
        e_info "  $USER is already in the docker group"
    else
        e_info "  Adding $USER to the docker group..."
        sudo usermod -aG docker "$USER"
        e_warn "  Log out and back in (or run: newgrp docker) for group membership to apply"
    fi

    mkdir -p "$HOME/.config/aliases"
    copy_config "$CONFIGS/aliases/.docker_aliases" "$HOME/.config/aliases/.docker_aliases"
    e_info "  Installed Docker aliases"

    INSTALLED+=("docker")
}

install_git_config() {
    e_info "\n[6/6] Git config (delta pager)"

    if ! command_exists delta; then
        e_warn "  git-delta not installed — config will be ready when delta is available"
    fi

    local gitconfig="$HOME/.gitconfig"

    # Only inject delta config if not already present
    if [ -f "$gitconfig" ] && grep -q '\[delta\]' "$gitconfig" 2>/dev/null; then
        e_info "  Delta config already present in ~/.gitconfig"
    else
        e_info "  Adding delta pager config to ~/.gitconfig"
        cat >> "$gitconfig" << 'DELTA'

[core]
  pager = delta
[interactive]
  diffFilter = delta --color-only
[delta]
  side-by-side = true
  navigate = true
  dark = true
[merge]
  conflictStyle = zdiff3
DELTA
    fi

    INSTALLED+=("git-config")
}

# ---------------------------------------------------------------------------
# Uninstall
# ---------------------------------------------------------------------------

uninstall() {
    e_warn "This will remove configs installed by Server CLI Tools."
    e_warn "Installed packages (apt) will NOT be removed."
    echo ""
    printf "Continue? [y/N] "
    read -r confirm
    case "$confirm" in
        y|Y) ;;
        *) echo "Aborted."; exit 0 ;;
    esac

    local removed=()

    # Aliases + custom tools
    if [ -d "$HOME/.config/aliases" ]; then
        rm -rf "$HOME/.config/aliases"
        removed+=("aliases")
    fi
    if [ -d "$HOME/.config/custom_tools" ]; then
        rm -rf "$HOME/.config/custom_tools"
        removed+=("custom-tools")
    fi

    # Terminal configs
    if [ -f "$HOME/.config/bat/config" ]; then
        rm -f "$HOME/.config/bat/config"
        removed+=("bat-config")
    fi
    # Zsh theme + zshrc
    if [ -f "$HOME/.config/zsh/zhann-elvis.zsh-theme" ]; then
        rm -f "$HOME/.config/zsh/zhann-elvis.zsh-theme"
        removed+=("zsh-theme")
    fi
    if [ -f "$HOME/.zshrc" ]; then
        rm -f "$HOME/.zshrc"
        removed+=("zshrc")
    fi

    # Oh-My-Zsh plugins (only the ones we installed)
    local zsh_custom="${ZSH_CUSTOM:-$HOME/.oh-my-zsh/custom}"
    if [ -d "$zsh_custom/plugins/zsh-autosuggestions" ]; then
        rm -rf "$zsh_custom/plugins/zsh-autosuggestions"
        removed+=("zsh-autosuggestions")
    fi
    if [ -d "$zsh_custom/plugins/zsh-syntax-highlighting" ]; then
        rm -rf "$zsh_custom/plugins/zsh-syntax-highlighting"
        removed+=("zsh-syntax-highlighting")
    fi

    # Git config — strip delta block
    local gitconfig="$HOME/.gitconfig"
    if [ -f "$gitconfig" ] && grep -q '\[delta\]' "$gitconfig" 2>/dev/null; then
        local tmp
        tmp=$(mktemp)
        awk '
            /^\[core\]/ { if (skip==0) { peek=1; hold=$0; next } }
            peek==1 {
                if ($0 ~ /pager *= *delta/) { skip=1; next }
                else { print hold; peek=0 }
            }
            /^\[interactive\]/ && skip { next }
            /^\[delta\]/ { skip=1; next }
            /^\[merge\]/ && skip { skip_merge=1; next }
            skip_merge==1 { skip_merge=0; skip=0; next }
            /^\[/ { skip=0 }
            skip { next }
            { print }
        ' "$gitconfig" > "$tmp"
        mv "$tmp" "$gitconfig"
        removed+=("git-delta-config")
    fi

    echo ""
    if [ ${#removed[@]} -gt 0 ]; then
        e_succ "Removed:"
        for item in "${removed[@]}"; do
            echo "  - $item"
        done
    else
        e_info "Nothing to remove."
    fi

    # Offer to restore backups
    local bkp_base="$HOME/.server_cli_tools_bkp"
    if [ -d "$bkp_base" ]; then
        echo ""
        local latest
        latest=$(ls -1t "$bkp_base" 2>/dev/null | head -n1)
        if [ -n "$latest" ]; then
            e_info "Backup found: $bkp_base/$latest"
            printf "Restore from this backup? [y/N] "
            read -r restore
            case "$restore" in
                y|Y)
                    cp -a "$bkp_base/$latest"/. "$HOME"/
                    e_succ "Restored from $bkp_base/$latest"
                    ;;
                *) e_info "Skipping restore." ;;
            esac
        fi
    fi

    echo ""
}

# ---------------------------------------------------------------------------
# Menu
# ---------------------------------------------------------------------------

COMPONENTS=(
    "Core packages (vim, bat, eza, fzf, htop, tmux, rg, fd, zoxide, delta)"
    "Zsh + Oh-My-Zsh (shell, plugins, theme)"
    "Aliases + custom tools"
    "Terminal configs (bat)"
    "Docker (engine + aliases)"
    "Git config (delta pager)"
)

INSTALLERS=(
    install_core_packages
    install_zsh
    install_aliases
    install_terminal_configs
    install_docker
    install_git_config
)

show_menu() {
    local count=${#COMPONENTS[@]}
    local selected=()
    for ((i = 0; i < count; i++)); do
        selected+=(1)
    done

    while true; do
        safe_clear
        echo ""
        e_info "Server CLI Tools — Installer"
        echo "============================="
        echo ""
        echo "Select components (enter number to toggle, a=all, n=none):"
        echo ""

        for ((i = 0; i < count; i++)); do
            local mark="   "
            if [ "${selected[$i]}" -eq 1 ]; then
                mark=" x "
            fi
            printf "  [%s] %d) %s\n" "$mark" "$((i + 1))" "${COMPONENTS[$i]}"
        done

        echo ""
        echo "  [a] Select all    [n] Select none    [Enter] Install    [q] Quit"
        echo ""
        printf "  > "
        read -r choice

        case "$choice" in
            q|Q)
                echo "Aborted."
                exit 0
                ;;
            a|A)
                for ((i = 0; i < count; i++)); do
                    selected[$i]=1
                done
                ;;
            n|N)
                for ((i = 0; i < count; i++)); do
                    selected[$i]=0
                done
                ;;
            "")
                # Run selected installers
                local any=0
                for ((i = 0; i < count; i++)); do
                    if [ "${selected[$i]}" -eq 1 ]; then
                        any=1
                    fi
                done
                if [ "$any" -eq 0 ]; then
                    e_warn "Nothing selected!"
                    sleep 1
                    continue
                fi

                echo ""
                for ((i = 0; i < count; i++)); do
                    if [ "${selected[$i]}" -eq 1 ]; then
                        ${INSTALLERS[$i]}
                    else
                        SKIPPED+=("${COMPONENTS[$i]}")
                    fi
                done
                return
                ;;
            *)
                if [[ "$choice" =~ ^[0-9]+$ ]] && [ "$choice" -ge 1 ] && [ "$choice" -le "$count" ]; then
                    local idx=$((choice - 1))
                    if [ "${selected[$idx]}" -eq 1 ]; then
                        selected[$idx]=0
                    else
                        selected[$idx]=1
                    fi
                fi
                ;;
        esac
    done
}

# ---------------------------------------------------------------------------
# Summary
# ---------------------------------------------------------------------------

print_summary() {
    echo ""
    echo "==========================================="
    e_succ "  Installation complete!"
    echo "==========================================="

    if [ ${#INSTALLED[@]} -gt 0 ]; then
        echo ""
        e_succ "Installed:"
        for item in "${INSTALLED[@]}"; do
            echo "  + $item"
        done
    fi

    if [ ${#SKIPPED[@]} -gt 0 ]; then
        echo ""
        e_warn "Skipped:"
        for item in "${SKIPPED[@]}"; do
            echo "  - $item"
        done
    fi

    if [ -d "$BACKUP_DIR" ]; then
        echo ""
        e_info "Backups saved to: $BACKUP_DIR"
    fi

    echo ""
    e_info "To apply changes, start a new shell or run:"
    echo "  exec zsh"
    echo ""
    e_info "Type 'h' to see all available aliases."
    echo ""
}

# ---------------------------------------------------------------------------
# Main
# ---------------------------------------------------------------------------

usage() {
    echo "Usage: $0 [OPTIONS]"
    echo ""
    echo "Options:"
    echo "  --all           Install all components (non-interactive)"
    echo "  --update        Pull latest changes and re-run installer"
    echo "  --update --all  Pull latest and install all (non-interactive)"
    echo "  --uninstall     Remove installed configs (keeps packages)"
    echo "  --help          Show this help message"
    echo ""
    echo "Without options, an interactive menu is shown."
}

main() {
    case "${1:-}" in
        --help|-h)
            usage
            exit 0
            ;;
        --uninstall)
            uninstall
            exit 0
            ;;
        --update)
            e_info "Pulling latest changes..."
            git -C "$SCRIPT_DIR" pull || { e_err "git pull failed"; exit 1; }
            echo ""
            check_os
            if [ "${2:-}" = "--all" ] || [ "${2:-}" = "-a" ]; then
                e_info "Server CLI Tools — installing all components"
                for installer in "${INSTALLERS[@]}"; do
                    $installer
                done
            else
                show_menu
            fi
            print_summary
            ;;
        --all|-a)
            check_os
            e_info "Server CLI Tools — installing all components"
            for installer in "${INSTALLERS[@]}"; do
                $installer
            done
            print_summary
            ;;
        "")
            check_os
            show_menu
            print_summary
            ;;
        *)
            e_err "Unknown option: $1"
            usage
            exit 1
            ;;
    esac
}

main "$@"