#!/usr/bin/env bash

set -e

# Check for required dependencies
check_dependencies() {
	local missing_deps=()
	
	if ! command -v pandoc &> /dev/null; then
		missing_deps+=("pandoc")
	fi
	
	if ! command -v xelatex &> /dev/null; then
		# Try lualatex as fallback
		if ! command -v lualatex &> /dev/null; then
			missing_deps+=("xelatex or lualatex (LaTeX engine)")
		fi
	fi
	
	if [ ${#missing_deps[@]} -ne 0 ]; then
		echo "Error: Missing required dependencies:"
		for dep in "${missing_deps[@]}"; do
			echo "  - $dep"
		done
		echo ""
		echo "Installation:"
		echo "  macOS: brew install pandoc"
		echo "  macOS: brew install --cask mactex"
		echo ""
		echo "  Linux: apt install pandoc texlive-xetex"
		exit 1
	fi
}

check_dependencies

# Detect available PDF engine
if command -v xelatex &> /dev/null; then
	PDF_ENGINE="xelatex"
elif command -v lualatex &> /dev/null; then
	PDF_ENGINE="lualatex"
else
	echo "Error: No suitable PDF engine found"
	exit 1
fi

SCRIPT_DIR=$(dirname "$0")
INPUT_DIR=$(cd "$(dirname "$SCRIPT_DIR")" && pwd)
OUTPUT_DIR="$INPUT_DIR/output"
TEMP_DIR="$OUTPUT_DIR/temp"

# Create output directory if it doesn't exist
mkdir -p "$OUTPUT_DIR"
mkdir -p "$TEMP_DIR"

# Preprocess Markdown files to convert Hugo shortcodes
echo "Preprocessing Markdown files..."
python3 "${SCRIPT_DIR}/preprocess-epub.py" "${INPUT_DIR}/content/zh" "$TEMP_DIR"

convert_to_pdf() {
	# Convert all Markdown files into a single PDF book
	OUTPUT_BOOK="$OUTPUT_DIR/ddia.pdf"
	rm -f "$OUTPUT_BOOK"
	echo "Converting all Markdown files into $OUTPUT_BOOK..."

	local meta_file=${INPUT_DIR}/metadata.yaml
	local header_file=${SCRIPT_DIR}/header.tex

	# Use xelatex for Chinese support with custom header
	pandoc -o "$OUTPUT_BOOK" \
		--metadata-file="$meta_file" \
		-H "$header_file" \
		--toc \
		--toc-depth=2 \
		--top-level-division=chapter \
		--file-scope=true \
		--pdf-engine="$PDF_ENGINE" \
		-V geometry:margin=1in \
		-V linestretch=1.5 \
		"${TEMP_DIR}"/_index.md \
		"${TEMP_DIR}"/preface.md \
		"${TEMP_DIR}"/part-i.md \
		"${TEMP_DIR}"/ch1.md \
		"${TEMP_DIR}"/ch2.md \
		"${TEMP_DIR}"/ch3.md \
		"${TEMP_DIR}"/ch4.md \
		"${TEMP_DIR}"/part-ii.md \
		"${TEMP_DIR}"/ch5.md \
		"${TEMP_DIR}"/ch6.md \
		"${TEMP_DIR}"/ch7.md \
		"${TEMP_DIR}"/ch8.md \
		"${TEMP_DIR}"/ch9.md \
		"${TEMP_DIR}"/part-iii.md \
		"${TEMP_DIR}"/ch10.md \
		"${TEMP_DIR}"/ch11.md \
		"${TEMP_DIR}"/ch12.md \
		"${TEMP_DIR}"/ch13.md \
		"${TEMP_DIR}"/ch14.md \
		"${TEMP_DIR}"/colophon.md \
		"${TEMP_DIR}"/glossary.md

	echo "PDF book created at $OUTPUT_BOOK."
}

convert_to_pdf

# Clean up temporary files
rm -rf "$TEMP_DIR"