#!/bin/bash

# =============================================================================
# Linux-BF: Bangla Font Installer for Linux
# Author: @abusayed0206
# Website: https://banglafont.pages.dev
# GitHub: https://github.com/abusayed0206/linux-bf
# Description: Universal installer for Bangla fonts on all major Linux distros
# =============================================================================

set -euo pipefail  # Exit on error, undefined vars, pipe failures

# Colors and formatting
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
MAGENTA='\033[0;35m'
CYAN='\033[0;36m'
WHITE='\033[1;37m'
NC='\033[0m' # No Color
BOLD='\033[1m'

# Configuration
SCRIPT_NAME="Linux-BF Installer"
VERSION="2.0.0"
FONTS_JSON_URL="https://banglafont.pages.dev/fonts.json"
USER_FONTS_DIR="$HOME/.local/share/fonts/bangla-fonts"
SYSTEM_FONTS_DIR="/usr/share/fonts/bangla-fonts"
TEMP_DIR="/tmp/linux-bf-installer-$$"
LOG_FILE="/tmp/linux-bf-install.log"

# Default options
INSTALL_MODE="user"  # user or system
FORCE_INSTALL=false
DRY_RUN=false
SELECTED_FONTS=""
VERBOSE=false

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

log() {
    echo "$(date '+%Y-%m-%d %H:%M:%S'): $*" >> "$LOG_FILE"
}

print_header() {
    clear
    echo -e "${CYAN}${BOLD}"
    echo "┌─────────────────────────────────────────────────────────────┐"
    echo "│                     🇧🇩 Linux-BF v$VERSION                      │"
    echo "│              Bangla Font Installer for Linux               │"
    echo "│                                                             │"
    echo "│  Author: @abusayed0206                                      │"
    echo "│  Website: https://banglafont.pages.dev                      │"
    echo "└─────────────────────────────────────────────────────────────┘"
    echo -e "${NC}"
}

print_success() {
    echo -e "${GREEN}✓${NC} $1"
    log "SUCCESS: $1"
}

print_error() {
    echo -e "${RED}✗${NC} $1" >&2
    log "ERROR: $1"
}

print_warning() {
    echo -e "${YELLOW}⚠${NC} $1"
    log "WARNING: $1"
}

print_info() {
    echo -e "${BLUE}ℹ${NC} $1"
    log "INFO: $1"
}

print_step() {
    echo -e "${MAGENTA}▶${NC} ${BOLD}$1${NC}"
    log "STEP: $1"
}

show_progress() {
    local current=$1
    local total=$2
    local width=50
    local percentage=$((current * 100 / total))
    local filled=$((current * width / total))
    
    printf "\r${CYAN}["
    printf "%${filled}s" | tr ' ' '='
    printf "%$((width - filled))s" | tr ' ' '-'
    printf "] %d%% (%d/%d)${NC}" "$percentage" "$current" "$total"
}

# =============================================================================
# System Detection and Dependencies
# =============================================================================

detect_distro() {
    if [[ -f /etc/os-release ]]; then
        . /etc/os-release
        DISTRO="$ID"
        DISTRO_FAMILY="$ID_LIKE"
    elif command -v lsb_release >/dev/null 2>&1; then
        DISTRO=$(lsb_release -si | tr '[:upper:]' '[:lower:]')
    else
        DISTRO="unknown"
    fi
    
    case "$DISTRO" in
        ubuntu|debian|mint|elementary|pop) PACKAGE_MANAGER="apt" ;;
        fedora|rhel|centos|rocky|almalinux) PACKAGE_MANAGER="dnf" ;;
        opensuse*|sles) PACKAGE_MANAGER="zypper" ;;
        arch|manjaro|endeavouros) PACKAGE_MANAGER="pacman" ;;
        *) PACKAGE_MANAGER="unknown" ;;
    esac
    
    print_info "Detected distribution: $DISTRO"
    [[ $VERBOSE == true ]] && print_info "Package manager: $PACKAGE_MANAGER"
}

check_dependencies() {
    local missing_deps=()
    local optional_deps=()
    
    # Check for required tools
    for cmd in curl fc-cache; do
        if ! command -v "$cmd" >/dev/null 2>&1; then
            missing_deps+=("$cmd")
        fi
    done
    
    # Check for optional but recommended tools
    if ! command -v jq >/dev/null 2>&1; then
        optional_deps+=("jq")
        print_warning "jq not found - using basic JSON parsing (slower but functional)"
    fi
    
    if [[ ${#missing_deps[@]} -gt 0 ]]; then
        print_error "Missing required dependencies: ${missing_deps[*]}"
        print_info "Please install missing dependencies:"
        
        case "$PACKAGE_MANAGER" in
            apt)
                echo -e "${YELLOW}sudo apt update && sudo apt install -y curl fontconfig${NC}"
                [[ ${#optional_deps[@]} -gt 0 ]] && echo -e "${CYAN}Optional: sudo apt install -y jq${NC}"
                ;;
            dnf)
                echo -e "${YELLOW}sudo dnf install -y curl fontconfig${NC}"
                [[ ${#optional_deps[@]} -gt 0 ]] && echo -e "${CYAN}Optional: sudo dnf install -y jq${NC}"
                ;;
            zypper)
                echo -e "${YELLOW}sudo zypper install -y curl fontconfig${NC}"
                [[ ${#optional_deps[@]} -gt 0 ]] && echo -e "${CYAN}Optional: sudo zypper install -y jq${NC}"
                ;;
            pacman)
                echo -e "${YELLOW}sudo pacman -S curl fontconfig${NC}"
                [[ ${#optional_deps[@]} -gt 0 ]] && echo -e "${CYAN}Optional: sudo pacman -S jq${NC}"
                ;;
            *)
                echo -e "${YELLOW}Please install: curl, fontconfig using your package manager${NC}"
                [[ ${#optional_deps[@]} -gt 0 ]] && echo -e "${CYAN}Optional: jq${NC}"
                ;;
        esac
        exit 1
    fi
    
    print_success "All required dependencies are available"
    [[ ${#optional_deps[@]} -gt 0 ]] && print_info "Consider installing optional dependencies for better performance: ${optional_deps[*]}"
}

check_permissions() {
    if [[ "$INSTALL_MODE" == "system" ]]; then
        if [[ $EUID -ne 0 ]]; then
            if command -v sudo >/dev/null 2>&1; then
                print_info "System installation requires sudo privileges"
                if ! sudo -n true 2>/dev/null; then
                    print_warning "You will be prompted for your password"
                fi
            else
                print_error "System installation requires root privileges, but sudo is not available"
                exit 1
            fi
        fi
    fi
}

# =============================================================================
# Font Management Functions
# =============================================================================

fetch_fonts_data() {
    print_step "Fetching font metadata from server..."
    
    if ! curl -s --fail --connect-timeout 10 --max-time 30 "$FONTS_JSON_URL" -o "$TEMP_DIR/fonts.json"; then
        print_error "Failed to fetch font metadata from $FONTS_JSON_URL"
        print_info "Please check your internet connection and try again"
        exit 1
    fi
    
    # Validate JSON
    if ! validate_json "$TEMP_DIR/fonts.json"; then
        print_error "Invalid JSON data received from server"
        exit 1
    fi
    
    TOTAL_FONTS=$(parse_json_array_length "$TEMP_DIR/fonts.json")
    print_success "Successfully fetched metadata for $TOTAL_FONTS fonts"
}

display_fonts() {
    local fonts_data="$TEMP_DIR/fonts.json"
    
    echo -e "\n${BOLD}${CYAN}Available Bangla Fonts:${NC}\n"
    
    printf "%-4s %-25s %-10s %-15s %s\n" "No." "Font Name" "Size" "Category" "Description"
    printf "%-4s %-25s %-10s %-15s %s\n" "----" "-------------------------" "----------" "---------------" "-------------------"
    
    for i in $(seq 0 $((TOTAL_FONTS - 1))); do
        local name=$(parse_json_field "$fonts_data" "$i" "name")
        local size=$(parse_json_field "$fonts_data" "$i" "size")
        local category=$(parse_json_field "$fonts_data" "$i" "category")
        local description=$(parse_json_field "$fonts_data" "$i" "description")
        
        # Truncate long descriptions
        if [[ ${#description} -gt 40 ]]; then
            description="${description:0:37}..."
        fi
        
        printf "%-4d %-25s %-10s %-15s %s\n" "$((i + 1))" "$name" "$size" "$category" "$description"
    done
    
    echo ""
}

get_user_selection() {
    if [[ -n "$SELECTED_FONTS" ]]; then
        return  # Selection already provided via command line
    fi
    
    echo -e "${BOLD}Installation Options:${NC}"
    echo "1. Install all fonts (recommended)"
    echo "2. Select specific fonts"
    echo "3. Exit"
    echo ""
    
    while true; do
        read -p "Choose an option (1-3): " choice
        case $choice in
            1)
                SELECTED_FONTS="all"
                break
                ;;
            2)
                echo -e "\n${YELLOW}Enter font numbers separated by commas (e.g., 1,3,5,8):${NC}"
                read -p "Font numbers: " SELECTED_FONTS
                if [[ "$SELECTED_FONTS" =~ ^[0-9,[:space:]]+$ ]]; then
                    break
                else
                    print_error "Invalid format. Please enter numbers separated by commas."
                fi
                ;;
            3)
                print_info "Installation cancelled by user"
                exit 0
                ;;
            *)
                print_error "Invalid option. Please choose 1, 2, or 3."
                ;;
        esac
    done
}

prepare_font_list() {
    local fonts_data="$TEMP_DIR/fonts.json"
    
    if [[ "$SELECTED_FONTS" == "all" ]]; then
        # Select all fonts
        for i in $(seq 0 $((TOTAL_FONTS - 1))); do
            echo "$i" >> "$TEMP_DIR/selected_fonts.txt"
        done
    else
        # Parse user selection
        echo "$SELECTED_FONTS" | tr ',' '\n' | while read -r num; do
            num=$(echo "$num" | tr -d '[:space:]')  # Remove whitespace
            if [[ "$num" -ge 1 && "$num" -le "$TOTAL_FONTS" ]]; then
                echo "$((num - 1))" >> "$TEMP_DIR/selected_fonts.txt"
            else
                print_warning "Invalid font number: $num (skipping)"
            fi
        done
    fi
    
    if [[ ! -f "$TEMP_DIR/selected_fonts.txt" ]] || [[ ! -s "$TEMP_DIR/selected_fonts.txt" ]]; then
        print_error "No valid fonts selected"
        exit 1
    fi
    
    SELECTED_COUNT=$(wc -l < "$TEMP_DIR/selected_fonts.txt")
    print_info "Selected $SELECTED_COUNT font(s) for installation"
}

download_and_install_fonts() {
    local fonts_data="$TEMP_DIR/fonts.json"
    local target_dir
    
    # Determine target directory
    if [[ "$INSTALL_MODE" == "system" ]]; then
        target_dir="$SYSTEM_FONTS_DIR"
        if [[ $EUID -ne 0 ]]; then
            print_step "Installing fonts system-wide (requires sudo)..."
        else
            print_step "Installing fonts system-wide..."
        fi
    else
        target_dir="$USER_FONTS_DIR"
        print_step "Installing fonts for current user..."
    fi
    
    print_info "Target directory: $target_dir"
    
    if [[ "$DRY_RUN" == true ]]; then
        print_warning "DRY RUN MODE - No files will be downloaded or installed"
        while read -r font_index; do
            local name=$(parse_json_field "$fonts_data" "$font_index" "name")
            local size=$(parse_json_field "$fonts_data" "$font_index" "size")
            echo -e "${CYAN}Would install:${NC} $name ($size)"
        done < "$TEMP_DIR/selected_fonts.txt"
        return 0
    fi
    
    # Create target directory
    if [[ "$INSTALL_MODE" == "system" ]]; then
        if [[ $EUID -ne 0 ]]; then
            sudo mkdir -p "$target_dir"
        else
            mkdir -p "$target_dir"
        fi
    else
        mkdir -p "$target_dir"
    fi
    
    # Download and install fonts
    local current=0
    local failed_fonts=()
    
    while read -r font_index; do
        current=$((current + 1))
        
        local name=$(parse_json_field "$fonts_data" "$font_index" "name")
        local url=$(parse_json_field "$fonts_data" "$font_index" "url")
        local filename=$(parse_json_field "$fonts_data" "$font_index" "filename")
        local size=$(parse_json_field "$fonts_data" "$font_index" "size")
        
        show_progress "$current" "$SELECTED_COUNT"
        
        # Download font
        local temp_font="$TEMP_DIR/$filename"
        if curl -s --fail --connect-timeout 10 --max-time 60 "$url" -o "$temp_font"; then
            # Verify download
            if [[ -f "$temp_font" ]] && [[ -s "$temp_font" ]]; then
                # Install font
                if [[ "$INSTALL_MODE" == "system" ]]; then
                    if [[ $EUID -ne 0 ]]; then
                        sudo cp "$temp_font" "$target_dir/"
                    else
                        cp "$temp_font" "$target_dir/"
                    fi
                else
                    cp "$temp_font" "$target_dir/"
                fi
                
                [[ $VERBOSE == true ]] && echo -e "\n${GREEN}✓${NC} $name ($size)"
            else
                failed_fonts+=("$name")
                [[ $VERBOSE == true ]] && echo -e "\n${RED}✗${NC} $name (download verification failed)"
            fi
        else
            failed_fonts+=("$name")
            [[ $VERBOSE == true ]] && echo -e "\n${RED}✗${NC} $name (download failed)"
        fi
    done < "$TEMP_DIR/selected_fonts.txt"
    
    echo ""  # New line after progress bar
    
    # Report results
    local successful=$((SELECTED_COUNT - ${#failed_fonts[@]}))
    print_success "Successfully installed $successful/$SELECTED_COUNT fonts"
    
    if [[ ${#failed_fonts[@]} -gt 0 ]]; then
        print_warning "Failed to install ${#failed_fonts[@]} font(s):"
        for font in "${failed_fonts[@]}"; do
            echo "  - $font"
        done
    fi
}

refresh_font_cache() {
    print_step "Refreshing font cache..."
    
    if [[ "$DRY_RUN" == true ]]; then
        print_warning "DRY RUN MODE - Font cache would be refreshed"
        return 0
    fi
    
    # Refresh user font cache
    if fc-cache -f "$USER_FONTS_DIR" 2>/dev/null; then
        [[ $VERBOSE == true ]] && print_success "User font cache refreshed"
    fi
    
    # Refresh system font cache if installing system-wide
    if [[ "$INSTALL_MODE" == "system" ]]; then
        if [[ $EUID -ne 0 ]]; then
            if sudo fc-cache -f "$SYSTEM_FONTS_DIR" 2>/dev/null; then
                [[ $VERBOSE == true ]] && print_success "System font cache refreshed"
            fi
        else
            if fc-cache -f "$SYSTEM_FONTS_DIR" 2>/dev/null; then
                [[ $VERBOSE == true ]] && print_success "System font cache refreshed"
            fi
        fi
    fi
    
    # Global font cache refresh
    if [[ "$INSTALL_MODE" == "system" ]]; then
        if [[ $EUID -ne 0 ]]; then
            sudo fc-cache -fv >/dev/null 2>&1 || true
        else
            fc-cache -fv >/dev/null 2>&1 || true
        fi
    else
        fc-cache -fv >/dev/null 2>&1 || true
    fi
    
    print_success "Font cache refreshed successfully"
}

# =============================================================================
# Cleanup and Error Handling
# =============================================================================

cleanup() {
    if [[ -d "$TEMP_DIR" ]]; then
        rm -rf "$TEMP_DIR"
    fi
}

trap cleanup EXIT

# =============================================================================
# Help and Usage
# =============================================================================

show_help() {
    cat << EOF
${BOLD}Linux-BF: Bangla Font Installer v$VERSION${NC}

${BOLD}USAGE:${NC}
    $0 [OPTIONS]

${BOLD}OPTIONS:${NC}
    -h, --help          Show this help message
    -v, --version       Show version information
    --verbose           Enable verbose output
    --system            Install fonts system-wide (requires sudo)
    --user              Install fonts for current user only (default)
    --dry-run           Preview what would be installed without making changes
    --force             Install without confirmation prompts
    --select NUMBERS    Select specific fonts by numbers (e.g., --select 1,3,5)
    --all               Install all available fonts
    --list              List available fonts and exit

${BOLD}EXAMPLES:${NC}
    $0                          # Interactive installation (user-level)
    $0 --system                 # Interactive installation (system-wide)
    $0 --all --user             # Install all fonts for current user
    $0 --select 1,3,5 --system  # Install specific fonts system-wide
    $0 --dry-run --all          # Preview installation of all fonts
    $0 --list                   # List available fonts

${BOLD}REMOTE INSTALLATION:${NC}
    curl -sSL https://banglafont.pages.dev/install.sh | bash
    curl -sSL https://banglafont.pages.dev/install.sh | sudo bash  # system-wide

${BOLD}PATHS:${NC}
    User fonts:   $USER_FONTS_DIR
    System fonts: $SYSTEM_FONTS_DIR
    Log file:     $LOG_FILE

${BOLD}SUPPORT:${NC}
    Website: https://banglafont.pages.dev
    GitHub:  https://github.com/abusayed0206/linux-bf
    Issues:  https://github.com/abusayed0206/linux-bf/issues

EOF
}

# =============================================================================
# JSON Parsing Functions (with fallbacks)
# =============================================================================

# Parse JSON using jq if available, otherwise use basic bash parsing
parse_json_array_length() {
    local json_file="$1"
    
    if command -v jq >/dev/null 2>&1; then
        jq length "$json_file"
    else
        # Basic fallback - count objects by counting opening braces after array start
        grep -o '{' "$json_file" | wc -l
    fi
}

parse_json_field() {
    local json_file="$1"
    local index="$2"
    local field="$3"
    
    if command -v jq >/dev/null 2>&1; then
        jq -r ".[$index].$field // \"\"" "$json_file"
    else
        # Basic fallback parsing - this is limited but functional
        case "$field" in
            name)
                sed -n "$((index + 1)),$((index + 50))p" "$json_file" | grep '"name"' | head -1 | sed 's/.*"name"[[:space:]]*:[[:space:]]*"\([^"]*\)".*/\1/'
                ;;
            url)
                sed -n "$((index + 1)),$((index + 50))p" "$json_file" | grep '"url"' | head -1 | sed 's/.*"url"[[:space:]]*:[[:space:]]*"\([^"]*\)".*/\1/'
                ;;
            filename)
                sed -n "$((index + 1)),$((index + 50))p" "$json_file" | grep '"filename"' | head -1 | sed 's/.*"filename"[[:space:]]*:[[:space:]]*"\([^"]*\)".*/\1/'
                ;;
            size)
                sed -n "$((index + 1)),$((index + 50))p" "$json_file" | grep '"size"' | head -1 | sed 's/.*"size"[[:space:]]*:[[:space:]]*"\([^"]*\)".*/\1/'
                ;;
            category)
                sed -n "$((index + 1)),$((index + 50))p" "$json_file" | grep '"category"' | head -1 | sed 's/.*"category"[[:space:]]*:[[:space:]]*"\([^"]*\)".*/\1/' || echo "general"
                ;;
            description)
                sed -n "$((index + 1)),$((index + 50))p" "$json_file" | grep '"description"' | head -1 | sed 's/.*"description"[[:space:]]*:[[:space:]]*"\([^"]*\)".*/\1/' || echo "A beautiful Bangla font"
                ;;
            *)
                echo ""
                ;;
        esac
    fi
}

validate_json() {
    local json_file="$1"
    
    if command -v jq >/dev/null 2>&1; then
        jq empty "$json_file" 2>/dev/null
    else
        # Basic validation - check if file has matching braces and brackets
        local open_braces=$(grep -o '{' "$json_file" | wc -l)
        local close_braces=$(grep -o '}' "$json_file" | wc -l)
        local open_brackets=$(grep -o '\[' "$json_file" | wc -l)
        local close_brackets=$(grep -o '\]' "$json_file" | wc -l)
        
        [[ $open_braces -eq $close_braces && $open_brackets -eq $close_brackets ]]
    fi
}

# =============================================================================
# Main Function
# =============================================================================

main() {
    # Parse command line arguments
    while [[ $# -gt 0 ]]; do
        case $1 in
            -h|--help)
                show_help
                exit 0
                ;;
            -v|--version)
                echo "Linux-BF Installer v$VERSION"
                exit 0
                ;;
            --verbose)
                VERBOSE=true
                shift
                ;;
            --system)
                INSTALL_MODE="system"
                shift
                ;;
            --user)
                INSTALL_MODE="user"
                shift
                ;;
            --dry-run)
                DRY_RUN=true
                shift
                ;;
            --force)
                FORCE_INSTALL=true
                shift
                ;;
            --select)
                SELECTED_FONTS="$2"
                shift 2
                ;;
            --all)
                SELECTED_FONTS="all"
                shift
                ;;
            --list)
                # Initialize temp directory for listing
                mkdir -p "$TEMP_DIR"
                detect_distro
                check_dependencies
                fetch_fonts_data
                display_fonts
                exit 0
                ;;
            *)
                print_error "Unknown option: $1"
                echo "Use --help for usage information"
                exit 1
                ;;
        esac
    done
    
    # Initialize
    print_header
    mkdir -p "$TEMP_DIR"
    log "=== Linux-BF Installation Started ==="
    log "Version: $VERSION"
    log "Install mode: $INSTALL_MODE"
    log "PID: $$"
    
    # System checks
    detect_distro
    check_dependencies
    check_permissions
    
    # Fetch and display fonts
    fetch_fonts_data
    display_fonts
    
    # Get user selection
    get_user_selection
    prepare_font_list
    
    # Confirmation
    if [[ "$FORCE_INSTALL" != true && "$DRY_RUN" != true ]]; then
        echo -e "\n${YELLOW}Installation Summary:${NC}"
        echo "  Mode: $INSTALL_MODE"
        echo "  Fonts: $SELECTED_COUNT selected"
        if [[ "$INSTALL_MODE" == "system" ]]; then
            echo "  Target: $SYSTEM_FONTS_DIR"
        else
            echo "  Target: $USER_FONTS_DIR"
        fi
        echo ""
        
        read -p "Proceed with installation? (y/N): " confirm
        case $confirm in
            [Yy]|[Yy][Ee][Ss])
                echo ""
                ;;
            *)
                print_info "Installation cancelled by user"
                exit 0
                ;;
        esac
    fi
    
    # Install fonts
    download_and_install_fonts
    refresh_font_cache
    
    # Final message
    if [[ "$DRY_RUN" != true ]]; then
        echo ""
        print_success "Installation completed successfully!"
        echo ""
        echo -e "${BOLD}${GREEN}🎉 Your Bangla fonts are now ready to use!${NC}"
        echo ""
        echo -e "${CYAN}Next steps:${NC}"
        echo "  1. Restart your applications to see the new fonts"
        echo "  2. Visit https://banglafont.pages.dev to preview fonts"
        echo "  3. Test fonts in your favorite text editor or browser"
        echo ""
        echo -e "${CYAN}Troubleshooting:${NC}"
        echo "  • If fonts don't appear, try logging out and back in"
        echo "  • Check the log file for details: $LOG_FILE"
        echo "  • Report issues: https://github.com/abusayed0206/linux-bf/issues"
        echo ""
        echo -e "${BOLD}Thank you for using Linux-BF! 🇧🇩${NC}"
    else
        print_info "Dry run completed. No changes were made."
    fi
    
    log "=== Linux-BF Installation Completed ==="
}

# =============================================================================
# Script Entry Point
# =============================================================================

# Check if script is being executed directly (not sourced)
# Handle case where BASH_SOURCE might not be available (e.g., when piped from curl)
if [[ "${BASH_SOURCE[0]:-$0}" == "${0}" ]]; then
    main "$@"
fi