#!/bin/bash
# -*- coding: utf-8 -*-
# File: scripts/shell/modules/validate_tex.src

THIS_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
# ---------------------------------------

source ./config/load_config.sh $SCITEX_WRITER_DOC_TYPE

# Make sure echo_error_soft is defined if not already defined
echo_error_soft() { echo -e "${RED}Error: $1${NC}"; }

display_latex_error_advice() {
    local error_log="$1"
    local input_file="$2"
    local message=""

    echo "File: ${input_file}"

    if grep -q "Missing \$ inserted" "$error_log"; then
        message="${message}- Math mode error: Check for unescaped special characters like '_', '^', or missing '$' delimiters\n"
        # Find potential problematic lines in the input file
        grep -n "[_^]" "$input_file" | head -5 | while read -r line; do
            message="${message}  Line ${line}\n"
        done
    fi

    if grep -q "Misplaced alignment tab character" "$error_log"; then
        message="${message}- Table formatting error: Check for unescaped '&' characters or mismatched table columns\n"
        grep -n "&" "$input_file" | head -5 | while read -r line; do
            message="${message}  Line ${line}\n"
        done
    fi

    if grep -q "Runaway argument" "$error_log"; then
        message="${message}- Missing brace error: Check for unbalanced '{' and '}' characters\n"
        local brackets=$(grep -n -o "[{}]" "$input_file" | sort -n)
        local count=0
        echo "$brackets" | while read -r line; do
            char=$(echo "$line" | cut -d: -f2)
            if [ "$char" = "{" ]; then
                ((count++))
            else
                ((count--))
            fi
            if [ $count -ne 0 ]; then
                line_num=$(echo "$line" | cut -d: -f1)
                message="${message}  Possible mismatch at line $line_num (balance: $count)\n"
                break
            fi
        done
    fi

    if grep -q "Undefined control sequence" "$error_log"; then
        # Extract the specific undefined command
        cmd=$(grep -o "\\\\[a-zA-Z]*" "$error_log" | grep -v "^\\\\input" | head -1)
        message="${message}- Undefined command: '$cmd' - Check spelling or add required package\n"
        # Find the line in the input file with this command
        grep -n "$cmd" "$input_file" | head -3 | while read -r line; do
            message="${message}  Line ${line}\n"
        done
    fi

    if [ -n "$message" ]; then
        echo -e "\033[1;33mCommon LaTeX Issues Detected:\033[0m"
        echo -e "$message"
    fi
}

# Validate a LaTeX file with detailed error reporting
validate_tex_file() {
    local tex_file="$1"
    local show_content="${2:-false}"
    local temp_dir=$(mktemp -d)
    local base_name=$(basename "$tex_file" .tex)
    local log_file="$temp_dir/${base_name}_complete.log"
    local preamble_file="$temp_dir/preamble.tex"

    # Create minimal preamble with all potentially needed packages
    cat >"$preamble_file" <<EOF
\\documentclass{article}
\\usepackage{booktabs}
\\usepackage{makecell}
\\usepackage{xcolor}
\\usepackage{caption}
\\usepackage{graphicx}
\\usepackage{gensymb}
\\usepackage{textcomp}
\\usepackage{hyperref}
\\usepackage{geometry}
\\usepackage{colortbl}
\\providecommand{\\restoregeometry}{}
\\providecommand{\\pdfbookmark}[3][]{}
\\providecommand{\\rowcolor}[1]{}
\\begin{document}
EOF

    # Create a temporary complete file
    cat "$preamble_file" "$tex_file" >"$temp_dir/${base_name}_complete.tex"
    echo "\\end{document}" >>"$temp_dir/${base_name}_complete.tex"

    # Show content if requested
    if [ "$show_content" = "true" ]; then
        echo "Content of $tex_file:"
        echo "----------------------------------------"
        nl -ba "$tex_file"
        echo "----------------------------------------"
    fi

    # Attempt to compile
    (cd "$temp_dir" && pdflatex -interaction=nonstopmode "${base_name}_complete.tex" >/dev/null 2>&1)
    local result=$?

    # Check log for errors
    if [ $result -ne 0 ] || grep -q "^!" "$log_file" 2>/dev/null; then
        echo_error_soft "LaTeX validation failed for $tex_file"
        grep -A 2 -B 2 "^!" "$log_file" 2>/dev/null
        display_latex_error_advice "$log_file" "$tex_file"
        rm -rf "$temp_dir"
        return 1 # Return non-zero to indicate failure
    fi

    rm -rf "$temp_dir"
    return 0 # Return zero to indicate success
}

# Exit immediately on fatal LaTeX errors
validate_tex_file_and_exit() {
    local tex_file="$1"

    if ! validate_tex_file "$tex_file" "true"; then
        echo_error_soft "Fatal error in table compilation of $tex_file. Exiting."
        echo_error_soft "Fix the issues before continuing."
        show_latex_escape_reference
        exit 1
    fi
    return 0
}

# Common LaTeX special characters that need escaping
latex_escape_reference() {
    cat <<'EOF'
+----------------+---------------+-------------------------------------------+
| Character      | LaTeX Escape  | Common Issues                             |
+----------------+---------------+-------------------------------------------+
| %              | \%            | Starts a comment in LaTeX                 |
| $              | \$            | Math mode delimiter                       |
| #              | \#            | Macro parameter reference                 |
| &              | \&            | Table column separator                    |
| _              | \_            | Subscript in math mode                    |
| {              | \{            | Begin group                               |
| }              | \}            | End group                                 |
| ~              | \~{}          | Non-breaking space                        |
| ^              | \^{}          | Superscript in math mode                  |
| \              | \textbackslash| Escape character                          |
| <              | \textless     | Less than symbol                          |
| >              | \textgreater  | Greater than symbol                       |
| |              | \textbar      | Vertical bar                              |
| "              | ``text''      | Use proper quotes                         |
| £              | \pounds       | Pound symbol                              |
| €              | \euro (needs  | Euro symbol                               |
|                | textcomp pkg) |                                           |
| ±              | \pm           | Plus-minus sign (math mode)               |
| ×              | \times        | Multiplication sign (math mode)           |
| ÷              | \div          | Division sign (math mode)                 |
| °              | \degree       | Degree symbol (needs gensymb)             |
| µ              | \mu           | Micro symbol (math mode)                  |
+----------------+---------------+-------------------------------------------+
EOF
}

# Check if pdflatex is available for validation
check_latex_available() {
    if ! command -v pdflatex >/dev/null 2>&1; then
        echo_warn "pdflatex not found. LaTeX validation will be skipped."
        return 1
    fi
    return 0
}

# Function to show LaTeX escape reference
show_latex_escape_reference() {
    echo -e "\033[1;36mLaTeX Special Characters Escape Reference:\033[0m"
    latex_escape_reference
}

# Check for special characters that might need LaTeX escaping
check_for_special_chars() {
    local input_file="$1"
    local problem_chars="[&%$#_{}^~\\|<>]"

    if grep -q "$problem_chars" "$input_file"; then
        echo_warn "Potential LaTeX special characters found in $input_file:"
        grep -n "$problem_chars" "$input_file" | head -5
        echo "These may need proper LaTeX escaping."
        return 1
    fi
    return 0
}

# Export functions to be used in other scripts
export -f latex_escape_reference
export -f check_latex_available
export -f display_latex_error_advice
export -f show_latex_escape_reference
export -f validate_tex_file
export -f check_for_special_chars
export -f validate_tex_file_and_exit

# EOF