#!/bin/bash

# STUPA PDF API - Build PDFs from LaTeX sources
# This script compiles the LaTeX templates into PDF forms

set -e

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m' # No Color

# Project directories
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
PROJECT_ROOT="$(cd "${SCRIPT_DIR}/.." && pwd)"
BACKEND_DIR="${PROJECT_ROOT}/backend"
ASSETS_DIR="${BACKEND_DIR}/assets"

# LaTeX template directories
LATEX_TEMPLATES_DIR="${BACKEND_DIR}/latex-templates"
LATEX_QSM_DIR="${BACKEND_DIR}/latex-qsm"
LATEX_VSM_DIR="${BACKEND_DIR}/latex-vsm"

# Function to check if required tools are installed
check_requirements() {
    echo -e "${BLUE}Checking requirements...${NC}"

    local missing=()

    # Check for git
    if ! command -v git &> /dev/null; then
        missing+=("git")
    fi

    # Check for xelatex
    if ! command -v xelatex &> /dev/null; then
        missing+=("xelatex (texlive-xetex)")
    fi

    # Check for latexmk
    if ! command -v latexmk &> /dev/null; then
        missing+=("latexmk")
    fi

    if [ ${#missing[@]} -ne 0 ]; then
        echo -e "${RED}Missing required tools: ${missing[*]}${NC}"
        echo "Please install them first:"
        echo "  sudo apt-get install git texlive-full texlive-xetex texlive-lang-german texlive-fonts-extra latexmk"
        exit 1
    fi

    echo -e "${GREEN}All requirements satisfied!${NC}"
}

# Function to setup git worktrees
setup_worktrees() {
    echo -e "${BLUE}Setting up LaTeX template worktrees...${NC}"

    cd "${LATEX_TEMPLATES_DIR}"

    # Remove existing worktrees if they exist
    if [ -d "${LATEX_QSM_DIR}" ]; then
        echo -e "${YELLOW}Removing existing QSM worktree...${NC}"
        git worktree remove --force "${LATEX_QSM_DIR}" 2>/dev/null || true
    fi

    if [ -d "${LATEX_VSM_DIR}" ]; then
        echo -e "${YELLOW}Removing existing VSM worktree...${NC}"
        git worktree remove --force "${LATEX_VSM_DIR}" 2>/dev/null || true
    fi

    # Create new worktrees
    echo -e "${BLUE}Creating QSM worktree...${NC}"
    git worktree add "${LATEX_QSM_DIR}" v1.2/QSM

    echo -e "${BLUE}Creating VSM worktree...${NC}"
    git worktree add "${LATEX_VSM_DIR}" v1.2/VSM

    echo -e "${GREEN}Worktrees created successfully!${NC}"
}

# Function to build a PDF from LaTeX
build_pdf() {
    local template_name=$1
    local source_dir=$2
    local output_name=$3

    echo -e "${BLUE}Building ${template_name} PDF...${NC}"

    # Change to source directory
    cd "${source_dir}"

    # Clean previous builds
    rm -f *.aux *.log *.out *.fdb_latexmk *.fls *.synctex.gz *.pdf

    # Build PDF using latexmk with xelatex
    echo -e "${YELLOW}Running latexmk with xelatex...${NC}"
    if latexmk -xelatex -interaction=nonstopmode -halt-on-error Main.tex; then
        echo -e "${GREEN}Build successful!${NC}"

        # Copy to assets directory
        if [ -f "Main.pdf" ]; then
            cp "Main.pdf" "${ASSETS_DIR}/${output_name}"
            echo -e "${GREEN}Copied to ${ASSETS_DIR}/${output_name}${NC}"
        else
            echo -e "${RED}Error: Main.pdf not found after build${NC}"
            return 1
        fi
    else
        echo -e "${RED}Build failed for ${template_name}${NC}"
        return 1
    fi

    # Clean up build artifacts
    echo -e "${YELLOW}Cleaning up...${NC}"
    rm -f *.aux *.log *.out *.fdb_latexmk *.fls *.synctex.gz
}

# Function to verify PDFs
verify_pdfs() {
    echo -e "${BLUE}Verifying generated PDFs...${NC}"

    local all_good=true

    # Check QSM PDF
    if [ -f "${ASSETS_DIR}/qsm.pdf" ]; then
        local size=$(stat -c%s "${ASSETS_DIR}/qsm.pdf" 2>/dev/null || stat -f%z "${ASSETS_DIR}/qsm.pdf" 2>/dev/null)
        if [ "$size" -gt 10000 ]; then
            echo -e "${GREEN}✓ qsm.pdf ($(($size / 1024)) KB)${NC}"
        else
            echo -e "${RED}✗ qsm.pdf is too small (${size} bytes)${NC}"
            all_good=false
        fi
    else
        echo -e "${RED}✗ qsm.pdf not found${NC}"
        all_good=false
    fi

    # Check VSM PDF
    if [ -f "${ASSETS_DIR}/vsm.pdf" ]; then
        local size=$(stat -c%s "${ASSETS_DIR}/vsm.pdf" 2>/dev/null || stat -f%z "${ASSETS_DIR}/vsm.pdf" 2>/dev/null)
        if [ "$size" -gt 10000 ]; then
            echo -e "${GREEN}✓ vsm.pdf ($(($size / 1024)) KB)${NC}"
        else
            echo -e "${RED}✗ vsm.pdf is too small (${size} bytes)${NC}"
            all_good=false
        fi
    else
        echo -e "${RED}✗ vsm.pdf not found${NC}"
        all_good=false
    fi

    if [ "$all_good" = true ]; then
        echo -e "${GREEN}All PDFs verified successfully!${NC}"
        return 0
    else
        echo -e "${RED}PDF verification failed!${NC}"
        return 1
    fi
}

# Main execution
main() {
    echo -e "${GREEN}STUPA PDF Builder${NC}"
    echo "=================="
    echo ""

    # Check requirements
    check_requirements

    # Create assets directory if it doesn't exist
    mkdir -p "${ASSETS_DIR}"

    # Setup worktrees if needed
    if [ ! -d "${LATEX_QSM_DIR}" ] || [ ! -d "${LATEX_VSM_DIR}" ]; then
        setup_worktrees
    fi

    # Build QSM PDF
    if ! build_pdf "QSM" "${LATEX_QSM_DIR}" "qsm.pdf"; then
        echo -e "${RED}Failed to build QSM PDF${NC}"
        exit 1
    fi

    # Build VSM PDF
    if ! build_pdf "VSM" "${LATEX_VSM_DIR}" "vsm.pdf"; then
        echo -e "${RED}Failed to build VSM PDF${NC}"
        exit 1
    fi

    # Verify results
    echo ""
    verify_pdfs

    echo ""
    echo -e "${GREEN}PDF build complete!${NC}"
    echo ""
    echo "Generated PDFs:"
    echo "  - ${ASSETS_DIR}/qsm.pdf"
    echo "  - ${ASSETS_DIR}/vsm.pdf"
}

# Run main function
main "$@"