#!/bin/bash

# Mission Statement:
# This script displays the contents of specified files with formatted headers.
# It provides optional file size limits through the -k flag (specified in KB).
# Without the -k flag, files are shown in their entirety.
# With -k flag, files larger than the specified size are truncated with a warning.
# The script handles both Linux and MacOS systems using compatible stat commands.
# Color output is available via the -c flag for better visual organization.

# ANSI color codes
BLUE='\033[0;34m'
GREEN='\033[0;32m'
RED='\033[0;31m'
NC='\033[0m' # No Color

usage() {
    echo "Usage: $(basename $0) [-k size_in_kb] [-c] files..."
    echo "  -k: Maximum file size in KB (optional)"
    echo "  -c: Enable color output"
    exit 1
}

# Initialize variables
COLOR=false
MAX_SIZE_KB=""

# Parse command line options
while getopts "k:c" opt; do
    case $opt in
        k) MAX_SIZE_KB="$OPTARG";;
        c) COLOR=true;;
        ?) usage;;
    esac
done

# Shift past the options
shift $((OPTIND-1))

# Check if any files were specified
if [ $# -eq 0 ]; then
    usage
fi

# Get file size in KB (compatible with both Linux and MacOS)
get_file_size() {
    if [[ "$OSTYPE" == "darwin"* ]]; then
        stat -f %z "$1"
    else
        stat --format=%s "$1"
    fi
}

# Format and display file header
show_header() {
    local file="$1"
    local size_bytes=$(get_file_size "$file")
    local size_kb=$((size_bytes / 1024))
    
    if $COLOR; then
        echo -e "\n${BLUE}=== File: ${GREEN}$file${BLUE} (${size_kb}KB) ===${NC}"
    else
        echo -e "\n=== File: $file (${size_kb}KB) ==="
    fi
}

# Process each file
for file in "$@"; do
    if [ ! -f "$file" ]; then
        if $COLOR; then
            echo -e "${RED}Error: '$file' does not exist or is not a regular file${NC}" >&2
        else
            echo "Error: '$file' does not exist or is not a regular file" >&2
        fi
        continue
    fi

    show_header "$file"
    
    if [ -n "$MAX_SIZE_KB" ]; then
        size_bytes=$(get_file_size "$file")
        size_kb=$((size_bytes / 1024))
        
        if [ $size_kb -gt $MAX_SIZE_KB ]; then
            if $COLOR; then
                echo -e "${RED}File size ($size_kb KB) exceeds limit ($MAX_SIZE_KB KB). Showing first $MAX_SIZE_KB KB:${NC}"
            else
                echo "File size ($size_kb KB) exceeds limit ($MAX_SIZE_KB KB). Showing first $MAX_SIZE_KB KB:"
            fi
            head -c $((MAX_SIZE_KB * 1024)) "$file"
            echo -e "\n[Truncated...]"
        else
            cat "$file"
        fi
    else
        cat "$file"
    fi
done