#!/bin/bash
set -e

SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
cd "$SCRIPT_DIR"

echo "=== Building j3270 Terminal Emulator ==="

# 1. Locate Java toolchain
JAVAC_BIN=""
JAR_BIN=""

if [ -n "$JAVA_HOME" ] && [ -x "$JAVA_HOME/bin/javac" ] && [ -x "$JAVA_HOME/bin/jar" ]; then
    JAVAC_BIN="$JAVA_HOME/bin/javac"
    JAR_BIN="$JAVA_HOME/bin/jar"
elif command -v javac >/dev/null 2>&1 && command -v jar >/dev/null 2>&1; then
    JAVAC_BIN="$(command -v javac)"
    JAR_BIN="$(command -v jar)"
else
    # Check common SDKMAN / macOS / Linux JDK locations
    POSSIBLE_HOMES=(
        "$HOME/.sdkman/candidates/java/current"
        "/Library/Java/JavaVirtualMachines"/*/Contents/Home
        "/usr/lib/jvm/default-java"
        "/usr/lib/jvm/java-21-openjdk"*
        "/usr/lib/jvm/java-17-openjdk"*
        "/usr/lib/jvm/java-11-openjdk"*
    )
    for h in "${POSSIBLE_HOMES[@]}"; do
        if [ -d "$h" ] && [ -x "$h/bin/javac" ] && [ -x "$h/bin/jar" ]; then
            export JAVA_HOME="$h"
            JAVAC_BIN="$JAVA_HOME/bin/javac"
            JAR_BIN="$JAVA_HOME/bin/jar"
            break
        fi
    done
fi

if [ -z "$JAVAC_BIN" ] || [ -z "$JAR_BIN" ]; then
    echo "ERROR: Java development tools (javac, jar) could not be found."
    echo "Please install JDK 11+ or set JAVA_HOME."
    exit 1
fi

echo "Using Java compiler: $JAVAC_BIN"
echo "Using JAR utility:   $JAR_BIN"

BUILD_DIR="$SCRIPT_DIR/build"
rm -rf "$BUILD_DIR/lib3270j" "$BUILD_DIR/j3270" "$BUILD_DIR/MANIFEST.MF"
mkdir -p "$BUILD_DIR/lib3270j" "$BUILD_DIR/j3270"

# 2. Compile lib3270j
echo "Compiling lib3270j..."
LIB_SOURCES=()
while IFS= read -r -d '' file; do
    LIB_SOURCES+=("$file")
done < <(find "$SCRIPT_DIR/lib3270j/src/main/java" -name "*.java" -print0)

if [ ${#LIB_SOURCES[@]} -eq 0 ]; then
    echo "ERROR: No sources found in lib3270j/src/main/java"
    exit 1
fi
"$JAVAC_BIN" -d "$BUILD_DIR/lib3270j" "${LIB_SOURCES[@]}"

# 3. Compile j3270
echo "Compiling j3270 application..."
APP_SOURCES=()
while IFS= read -r -d '' file; do
    APP_SOURCES+=("$file")
done < <(find "$SCRIPT_DIR/j3270/src/main/java" -name "*.java" -print0)

if [ ${#APP_SOURCES[@]} -eq 0 ]; then
    echo "ERROR: No sources found in j3270/src/main/java"
    exit 1
fi
"$JAVAC_BIN" -cp "$BUILD_DIR/lib3270j" -d "$BUILD_DIR/j3270" "${APP_SOURCES[@]}"

# Copy any resources if present
if [ -d "$SCRIPT_DIR/j3270/src/main/resources" ]; then
    cp -r "$SCRIPT_DIR/j3270/src/main/resources/"* "$BUILD_DIR/j3270/" 2>/dev/null || true
fi
if [ -d "$SCRIPT_DIR/lib3270j/src/main/resources" ]; then
    cp -r "$SCRIPT_DIR/lib3270j/src/main/resources/"* "$BUILD_DIR/lib3270j/" 2>/dev/null || true
fi

# 4. Package executable JAR
echo "Packaging j3270.jar..."
cat << 'EOF' > "$BUILD_DIR/MANIFEST.MF"
Manifest-Version: 1.0
Main-Class: org.pubvm.j3270.J3270App
Implementation-Title: j3270
Implementation-Version: 0.1.0
Created-By: j3270 build_all.sh
EOF

"$JAR_BIN" cvfm "$BUILD_DIR/j3270.jar" "$BUILD_DIR/MANIFEST.MF" \
    -C "$BUILD_DIR/lib3270j" . \
    -C "$BUILD_DIR/j3270" . > /dev/null

echo "=== Build Complete ==="
echo "Executable JAR created: $BUILD_DIR/j3270.jar"
ls -lh "$BUILD_DIR/j3270.jar"