#!/bin/bash

set -e

# 🔍 Detect OS and Package Manager
detect_platform() {
    if [[ "$OSTYPE" == "darwin"* ]]; then
        OS="macos"
        if ! command -v brew &>/dev/null; then
            echo "🍺 Homebrew not found. Install it now? (y/N): "
            read -r confirm
            if [[ "$confirm" =~ ^[Yy]$ ]]; then
                /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)"
            else
                echo "❌ Homebrew is required to install Fish on macOS. Exiting."
                exit 1
            fi
        fi
        PKG_MGR="brew"
    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
        echo "❌ Unsupported platform."
        exit 1
    fi
}

# 🔐 Install gpg if not present (Debian only)
install_gpg_if_needed() {
    if [[ "$OS" == "debian" ]] && ! command -v gpg &>/dev/null; then
        echo "🔑 gpg not found. Installing..."
        sudo apt update && sudo apt install -y gnupg
    fi
}

# 📦 Add Fish shell repo for Debian/Ubuntu
add_fish_repo_debian() {
    echo "Adding Fish shell repo for Debian/Ubuntu..."
    echo 'deb http://download.opensuse.org/repositories/shells:/fish:/release:/4/Debian_12/ /' | \
        sudo tee /etc/apt/sources.list.d/fish.list
    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
}

# 🐟 Install Fish shell
install_fish() {
    echo "🐟 Installing Fish shell for $OS..."

    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
}

# ♻️ Update Fish shell if needed
update_fish() {
    echo "🔄 Checking for updates to Fish shell..."
    case "$PKG_MGR" in
        apt)
            sudo apt update
            if apt list --upgradable 2>/dev/null | grep -q "^fish/"; then
                read -rp "An update is available. Update Fish? (y/N): " confirm
                [[ "$confirm" =~ ^[Yy]$ ]] && sudo apt install -y fish
            else
                echo "Fish is already up to date."
            fi
            ;;
        dnf|yum)
            sudo $PKG_MGR check-update || true
            if $PKG_MGR list updates | grep -q "^fish"; then
                read -rp "An update is available. Update Fish? (y/N): " confirm
                [[ "$confirm" =~ ^[Yy]$ ]] && sudo $PKG_MGR update -y fish
            else
                echo "Fish is already up to date."
            fi
            ;;
        pacman)
            sudo pacman -Sy --noconfirm
            if pacman -Qu | grep -q "^fish"; then
                read -rp "An update is available. Update Fish? (y/N): " confirm
                [[ "$confirm" =~ ^[Yy]$ ]] && sudo pacman -S --noconfirm fish
            else
                echo "Fish is already up to date."
            fi
            ;;
        brew)
            brew update
            if brew outdated | grep -q "^fish"; then
                read -rp "An update is available. Update Fish? (y/N): " confirm
                [[ "$confirm" =~ ^[Yy]$ ]] && brew upgrade fish
            else
                echo "Fish is already up to date."
            fi
            ;;
    esac
}

# 🎣 Install Fisher plugin manager
install_fisher() {
    echo "Installing Fisher plugin manager..."

    curl -fsSL https://git.mycod.in/apt/fish_install/raw/branch/main/install_fisher.fish -o /tmp/install_fisher.fish
    chmod +x /tmp/install_fisher.fish
    fish /tmp/install_fisher.fish
}

# 🧩 Install plugins via external .fish script
install_fish_plugins() {
    echo "Installing recommended Fish plugins..."

    curl -fsSL https://git.mycod.in/apt/fish_install/raw/branch/main/fish_plugins.fish -o /tmp/fish_plugins.fish
    chmod +x /tmp/fish_plugins.fish
    fish /tmp/fish_plugins.fish
}

# 🏁 Main script
detect_platform
install_gpg_if_needed

if command -v fish &>/dev/null; then
    echo "Fish shell is already installed."
    update_fish
else
    install_fish
fi

# Ask if user wants to install Fisher and plugins
read -rp "Do you want to install Fisher plugin manager and some plugins? (y/N): " install_plugins
if [[ "$install_plugins" =~ ^[Yy]$ ]]; then
    install_fisher
    install_fish_plugins
    echo "Fisher and plugins installed!"
else
    echo "Skipping plugin installation."
fi

echo "✅ Fish shell setup complete on $OS!"