#!/bin/bash
set -euo pipefail

# InternalAI Platform Installer

# ============================================================================
# Configuration
# ============================================================================

PLATFORM_NAME="InternalAI Platform"
DEFAULT_INSTALL_DIR="$HOME/internalai"
REPO_URL="https://gitea.app.monadical.io/monadical/internalai.git"
REPO_SSH="git@gitea.app.monadical.io:monadical/internalai.git"
CLI_INSTALL_DIR="/usr/local/bin"
CLI_NAME="internalai"
VERSION="1.0.0"

# Colors
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
CYAN='\033[0;36m'
BOLD='\033[1m'
NC='\033[0m'

# ============================================================================
# Logging Functions
# ============================================================================

log_info() {
    echo -e "${BLUE}ℹ${NC} $1"
}

log_success() {
    echo -e "${GREEN}✓${NC} $1"
}

log_warning() {
    echo -e "${YELLOW}⚠${NC} $1"
}

log_error() {
    echo -e "${RED}✗${NC} $1"
}

log_header() {
    echo ""
    echo -e "${CYAN}═══════════════════════════════════════════════════════════${NC}"
    echo -e "${CYAN}  $1${NC}"
    echo -e "${CYAN}═══════════════════════════════════════════════════════════${NC}"
    echo ""
}

print_banner() {
    clear
    echo -e "${BOLD}${CYAN}"
    cat << 'EOF'
╔═════════════════════════════════════════════════════════════════════════════════════════╗
║                                                                                         ║
║   ██╗███╗   ██╗████████╗███████╗██████╗ ███╗   ██╗ █████╗ ██╗          █████╗ ██╗       ║
║   ██║████╗  ██║╚══██╔══╝██╔════╝██╔══██╗████╗  ██║██╔══██╗██║         ██╔══██╗██║       ║
║   ██║██╔██╗ ██║   ██║   █████╗  ██████╔╝██╔██╗ ██║███████║██║         ███████║██║       ║
║   ██║██║╚██╗██║   ██║   ██╔══╝  ██╔══██╗██║╚██╗██║██╔══██║██║         ██╔══██║██║       ║
║   ██║██║ ╚████║   ██║   ███████╗██║  ██║██║ ╚████║██║  ██║███████╗    ██║  ██║██║       ║
║   ╚═╝╚═╝  ╚═══╝   ╚═╝   ╚══════╝╚═╝  ╚═╝╚═╝  ╚═══╝╚═╝  ╚═╝╚══════╝    ╚═╝  ╚═╝╚═╝       ║
║                                                                                         ║
║                              Platform Installer v${VERSION}                             ║
╚═════════════════════════════════════════════════════════════════════════════════════════╝
EOF
    echo -e "${NC}"
}

show_welcome() {
    print_banner
    log_info "This installer will:"
    echo "  • Check system dependencies"
    echo "  • Install missing dependencies (just, uv)"
    echo "  • Set up Gitea authentication"
    echo "  • Clone the InternalAI platform repository"
    echo "  • Install the 'internalai' command-line tool"
    echo ""
}

# ============================================================================
# Utility Functions
# ============================================================================

prompt() {
    local varname=$1
    local prompt_text=$2
    local default_value=$3
    local is_secret=${4:-false}

    if [ -n "$default_value" ]; then
        prompt_text="$prompt_text [${default_value}]"
    fi

    if [ "$is_secret" = true ]; then
        echo -ne "${YELLOW}${prompt_text}: ${NC}" >&2
        value=""
        while IFS= read -r -s -n1 char < /dev/tty; do
            if [[ $char == $'\0' ]]; then
                break
            fi
            if [[ $char == $'\177' ]] || [[ $char == $'\b' ]]; then
                if [ ${#value} -gt 0 ]; then
                    value="${value%?}"
                    echo -ne "\b \b" >&2
                fi
            else
                value+="$char"
                echo -n "*" >&2
            fi
        done
        echo "" >&2
    else
        echo -ne "${YELLOW}${prompt_text}: ${NC}" >&2
        read value < /dev/tty
    fi

    if [ -z "$value" ] && [ -n "$default_value" ]; then
        value="$default_value"
    fi

    eval "$varname='$value'"
}

# ============================================================================
# Dependency Checking and Installation
# ============================================================================

check_dependencies() {
    log_header "Checking Dependencies"

    local deps_ok=true

    # Check Git
    if command -v git &> /dev/null; then
        log_success "git installed ($(git --version | head -n1))"
    else
        log_error "git is not installed"
        deps_ok=false
    fi

    # Check Docker
    if command -v docker &> /dev/null; then
        log_success "docker installed ($(docker --version | head -n1))"
    else
        log_error "docker is not installed"
        deps_ok=false
    fi

    # Check Docker Compose
    if docker compose version &> /dev/null 2>&1; then
        log_success "docker compose installed ($(docker compose version | head -n1))"
    elif command -v docker-compose &> /dev/null; then
        log_success "docker-compose installed ($(docker-compose --version | head -n1))"
    else
        log_error "docker compose is not installed"
        deps_ok=false
    fi

    # Check bash version
    if [ "${BASH_VERSINFO[0]}" -lt 4 ]; then
        log_warning "Bash version ${BASH_VERSION} detected. Version 4+ recommended."
    else
        log_success "bash ${BASH_VERSION} is installed"
    fi

    # Check Just
    if command -v just &> /dev/null; then
        log_success "just installed ($(just --version | head -n1))"
    else
        log_warning "just is not installed (will attempt to install)"
        install_just
    fi

    # Check uv
    if command -v uv &> /dev/null; then
        log_success "uv installed ($(uv --version | head -n1))"
    else
        log_warning "uv is not installed (will attempt to install)"
        install_uv
    fi

    if [ "$deps_ok" = false ]; then
        log_error "Please install missing dependencies and try again"
        echo ""
        log_info "Installation guides:"
        log_info "  • Git: https://git-scm.com/downloads"
        log_info "  • Docker: https://docs.docker.com/get-docker/"
        exit 1
    fi
}

install_just() {
    # Try package managers first
    if [[ "$OSTYPE" == "darwin"* ]]; then
        if command -v brew &> /dev/null; then
            log_info "Installing just via Homebrew..."
            if brew install just; then
                log_success "just installed"
                return 0
            else
                log_warning "Homebrew installation failed, trying binary download..."
            fi
        fi
    elif [[ "$OSTYPE" == "linux-gnu"* ]]; then
        if command -v cargo &> /dev/null; then
            log_info "Installing just via cargo..."
            if cargo install just; then
                log_success "just installed"
                return 0
            else
                log_warning "Cargo installation failed, trying binary download..."
            fi
        fi
    fi

    # Fall back to downloading pre-built binary
    log_info "Downloading pre-built just binary..."

    # Detect architecture
    local arch=$(uname -m)
    local os=$(uname -s | tr '[:upper:]' '[:lower:]')

    # Map architecture names
    case "$arch" in
        x86_64) arch="x86_64" ;;
        aarch64|arm64) arch="aarch64" ;;
        *)
            log_error "Unsupported architecture: $arch"
            log_info "Please install just manually: https://github.com/casey/just#installation"
            exit 1
            ;;
    esac

    # Map OS names
    case "$os" in
        darwin) os="apple-darwin" ;;
        linux) os="unknown-linux-musl" ;;
        *)
            log_error "Unsupported OS: $os"
            log_info "Please install just manually: https://github.com/casey/just#installation"
            exit 1
            ;;
    esac

    # Get latest version from GitHub API
    log_info "Fetching latest version..."
    local latest_version=$(curl -fsSL https://api.github.com/repos/casey/just/releases/latest | grep '"tag_name"' | sed -E 's/.*"([^"]+)".*/\1/')

    if [ -z "$latest_version" ]; then
        log_error "Failed to fetch latest version"
        log_info "Please install just manually: https://github.com/casey/just#installation"
        exit 1
    fi

    local binary_name="just-${latest_version}-${arch}-${os}"
    local download_url="https://github.com/casey/just/releases/download/${latest_version}/${binary_name}.tar.gz"
    local install_dir="$HOME/.local/bin"

    # Create install directory
    mkdir -p "$install_dir"

    # Download and extract
    local tmp_dir=$(mktemp -d)
    trap "rm -rf $tmp_dir" EXIT

    log_info "Downloading from: $download_url"
    if ! curl -fsSL "$download_url" -o "$tmp_dir/just.tar.gz"; then
        log_error "Failed to download just binary"
        log_info "Please install just manually: https://github.com/casey/just#installation"
        exit 1
    fi

    log_info "Extracting to $install_dir..."
    if ! tar -xzf "$tmp_dir/just.tar.gz" -C "$tmp_dir"; then
        log_error "Failed to extract just binary"
        exit 1
    fi

    # Install binary
    if ! mv "$tmp_dir/just" "$install_dir/just"; then
        log_error "Failed to install just to $install_dir"
        exit 1
    fi

    chmod +x "$install_dir/just"

    # Add to PATH if not already there
    if [[ ":$PATH:" != *":$install_dir:"* ]]; then
        log_info "Adding $install_dir to PATH..."
        export PATH="$install_dir:$PATH"

        # Add to shell profile
        local shell_profile=""
        if [ -n "$BASH_VERSION" ]; then
            shell_profile="$HOME/.bashrc"
        elif [ -n "$ZSH_VERSION" ]; then
            shell_profile="$HOME/.zshrc"
        fi

        if [ -n "$shell_profile" ]; then
            echo "export PATH=\"$install_dir:\$PATH\"" >> "$shell_profile"
            log_info "Added to $shell_profile (restart shell or run: source $shell_profile)"
        fi
    fi

    # Verify installation
    if command -v just &> /dev/null; then
        log_success "just installed successfully to $install_dir/just"
    else
        log_warning "just installed to $install_dir/just but not found in PATH"
        log_info "You may need to restart your terminal or run:"
        log_info "  export PATH=\"$install_dir:\$PATH\""
    fi
}

install_uv() {
    log_info "Installing uv (Python package manager)..."

    if curl -LsSf https://astral.sh/uv/install.sh | sh; then
        # Add uv to PATH for current session
        export PATH="$HOME/.local/bin:$PATH"

        if command -v uv &> /dev/null; then
            log_success "uv installed successfully ($(uv --version | head -n1))"
        else
            log_error "uv installation succeeded but not found in PATH"
            log_info "You may need to restart your terminal or run:"
            log_info "  export PATH=\"\$HOME/.local/bin:\$PATH\""
            exit 1
        fi
    else
        log_error "Failed to install uv"
        log_info "Please install manually: curl -LsSf https://astral.sh/uv/install.sh | sh"
        exit 1
    fi
}

# ============================================================================
# Gitea Authentication
# ============================================================================

AUTH_TYPE=""
GITEA_TOKEN=""

setup_gitea_auth() {
    log_header "Gitea Authentication"

    log_info "The InternalAI platform repository is private and requires authentication."
    echo ""
    log_info "Choose authentication method:"
    echo "  1) Personal Access Token (recommended)"
    echo "  2) SSH Key (if already configured)"
    echo ""

    prompt AUTH_CHOICE "Select authentication method" "1"

    case "$AUTH_CHOICE" in
        1)
            AUTH_TYPE="token"
            echo ""
            log_info "To create a personal access token:"
            log_info "  1. Go to: https://gitea.app.monadical.io/user/settings/applications"
            log_info "  2. Click 'Generate New Token'"
            log_info "  3. Give it a name (e.g., 'InternalAI Setup')"
            log_info "  4. Give it Read repository scope"
            log_info "  5. Click 'Generate Token' and copy it"
            echo ""
            prompt GITEA_TOKEN "Enter your Gitea Personal Access Token" "" true

            if [ -z "$GITEA_TOKEN" ]; then
                log_error "Token is required"
                exit 1
            fi
            ;;
        2)
            AUTH_TYPE="ssh"
            log_info "Using SSH authentication"
            log_info "Ensure your SSH key is added to Gitea:"
            log_info "  https://gitea.app.monadical.io/user/settings/keys"

            # Test SSH connection
            echo ""
            log_info "Testing SSH connection..."
            if ssh -T git@gitea.app.monadical.io 2>&1 | grep -q "Hi there"; then
                log_success "SSH connection successful"
            else
                log_warning "Could not verify SSH connection, but will try to continue..."
            fi
            ;;
        *)
            log_error "Invalid choice"
            exit 1
            ;;
    esac
}

prepare_git_url() {
    if [ "$AUTH_TYPE" = "token" ] && [ -n "$GITEA_TOKEN" ]; then
        echo "$REPO_URL" | sed "s|https://gitea.app.monadical.io/|https://${GITEA_TOKEN}@gitea.app.monadical.io/|"
    elif [ "$AUTH_TYPE" = "ssh" ]; then
        echo "$REPO_SSH"
    else
        echo "$REPO_URL"
    fi
}

# ============================================================================
# Git Credential Caching
# ============================================================================

configure_git_credentials() {
    log_header "Configuring Git Credentials"

    if [ "$AUTH_TYPE" = "ssh" ]; then
        log_info "Using SSH - no credential caching needed"
        return
    fi

    # Detect OS and configure appropriate credential helper
    if [[ "$OSTYPE" == "darwin"* ]]; then
        # macOS - use keychain
        log_info "Configuring git to use macOS Keychain..."
        git config --global credential.helper osxkeychain
        log_success "Git credentials will be stored in macOS Keychain"
    elif [[ "$OSTYPE" == "linux-gnu"* ]]; then
        # Linux - try to use libsecret, fall back to cache
        if command -v git-credential-libsecret &> /dev/null; then
            log_info "Configuring git to use libsecret..."
            git config --global credential.helper libsecret
            log_success "Git credentials will be stored in system keyring"
        else
            log_info "Configuring git credential cache (1 hour)..."
            git config --global credential.helper 'cache --timeout=3600'
            log_success "Git credentials will be cached in memory for 1 hour"
            log_info "For persistent storage, install: libsecret"
        fi
    else
        # Unknown OS - use cache
        log_info "Configuring git credential cache (1 hour)..."
        git config --global credential.helper 'cache --timeout=3600'
        log_success "Git credentials will be cached in memory for 1 hour"
    fi

    # Store credentials by triggering a git operation
    if [ "$AUTH_TYPE" = "token" ] && [ -n "$INSTALL_DIR" ] && [ -d "$INSTALL_DIR/.git" ]; then
        log_info "Caching credentials..."
        cd "$INSTALL_DIR"
        # Trigger credential storage by doing a fetch (which uses credentials)
        git fetch --dry-run 2>&1 | grep -v "password\|token" > /dev/null || true
        log_success "Credentials cached successfully"
    fi
}

# ============================================================================
# Repository Cloning
# ============================================================================

clone_repository() {
    log_header "Cloning Repository"

    prompt INSTALL_DIR "Installation directory" "$DEFAULT_INSTALL_DIR"

    if [ -d "$INSTALL_DIR" ]; then
        if [ -d "$INSTALL_DIR/.git" ]; then
            log_warning "Directory already exists and appears to be a git repository"
            prompt UPDATE_CHOICE "Update existing repository? (y/n)" "y"
            if [[ "$UPDATE_CHOICE" =~ ^[Yy] ]]; then
                log_info "Pulling latest changes..."
                cd "$INSTALL_DIR"
                git pull
                log_success "Repository updated"
                return
            else
                log_info "Using existing repository"
                return
            fi
        else
            log_error "Directory exists but is not a git repository"
            log_info "Please remove or rename: $INSTALL_DIR"
            exit 1
        fi
    fi

    local git_url=$(prepare_git_url)

    log_info "Cloning repository to: $INSTALL_DIR"
    log_info "This may take a few minutes..."

    if git clone "$git_url" "$INSTALL_DIR" 2>&1 | grep -v "password\|token"; then
        log_success "Repository cloned successfully"
    else
        log_error "Failed to clone repository"
        log_info "Please check your credentials and try again"
        exit 1
    fi
}

# ============================================================================
# CLI Installation
# ============================================================================

install_cli() {
    log_header "Installing CLI Tool"

    local cli_script="$INSTALL_DIR/scripts/$CLI_NAME"

    if [ ! -f "$cli_script" ]; then
        log_error "CLI script not found at: $cli_script"
        exit 1
    fi

    log_info "Installing $CLI_NAME to $CLI_INSTALL_DIR..."

    if [ -w "$CLI_INSTALL_DIR" ]; then
        cp "$cli_script" "$CLI_INSTALL_DIR/$CLI_NAME"
        chmod +x "$CLI_INSTALL_DIR/$CLI_NAME"
    else
        log_warning "Need sudo permissions to write to $CLI_INSTALL_DIR"
        sudo cp "$cli_script" "$CLI_INSTALL_DIR/$CLI_NAME"
        sudo chmod +x "$CLI_INSTALL_DIR/$CLI_NAME"
    fi

    if command -v "$CLI_NAME" &> /dev/null; then
        log_success "$CLI_NAME installed successfully!"
    else
        log_warning "$CLI_NAME installed but not found in PATH"
        log_info "You may need to restart your terminal or run:"
        log_info "  export PATH=\"$CLI_INSTALL_DIR:\$PATH\""
    fi
}

# ============================================================================
# Post-Installation
# ============================================================================

show_next_steps() {
    log_header "Installation Complete!"

    echo -e "${GREEN}${BOLD}The InternalAI platform has been set up successfully!${NC}"
    echo ""
    echo -e "${BOLD}Platform Location:${NC} ${CYAN}$INSTALL_DIR${NC}"
    echo ""
    echo -e "${BOLD}Next Steps:${NC}"
    echo ""
    echo "  1. Configure and start the platform:"
    echo -e "     ${GREEN}$CLI_NAME install${NC}"
    echo ""
    echo "  2. View available commands:"
    echo -e "     ${GREEN}$CLI_NAME help${NC}"
    echo ""
    echo "  3. Check platform status:"
    echo -e "     ${GREEN}$CLI_NAME status${NC}"
    echo ""
    echo -e "${BOLD}Documentation:${NC}"
    echo "  • Platform docs: $INSTALL_DIR/docs/"
    echo "  • README: $INSTALL_DIR/README.md"
    echo ""
}

# ============================================================================
# Main Installation Flow
# ============================================================================

main() {
    show_welcome

    check_dependencies
    setup_gitea_auth
    clone_repository
    configure_git_credentials
    install_cli
    show_next_steps

    echo -e "${GREEN}${BOLD}Setup completed successfully!${NC}"
    echo ""
}

main "$@"