import streamlit as st
import os, zipfile, subprocess, shutil

st.set_page_config(page_title="Android Build Server", layout="centered")
st.title("📱 Android APK Generator")
st.markdown("Flutter ya Native Android — dono projects ka APK banayega aur **Auto-Sign** karega.")

def setup_java_env():
    # Automatically detect valid JAVA_HOME path from system java binary
    current_jh = os.environ.get("JAVA_HOME", "")
    if not current_jh or not os.path.exists(os.path.join(current_jh, "bin", "java")):
        java_bin = shutil.which("java")
        if java_bin:
            real_path = os.path.realpath(java_bin)
            detected_jh = os.path.dirname(os.path.dirname(real_path))
            os.environ["JAVA_HOME"] = detected_jh

def generate_keystore():
    kp = "debug.keystore"
    if not os.path.exists(kp):
        subprocess.run([
            "keytool","-genkey","-v","-keystore",kp,"-storepass","android",
            "-alias","androiddebugkey","-keypass","android","-keyalg","RSA",
            "-keysize","2048","-validity","10000",
            "-dname","CN=AndroidDebug,O=Android,C=US"
        ], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
    return kp

def find_apk(d):
    for r,_,fs in os.walk(d):
        for f in fs:
            if f.endswith(".apk") and "release" in f.lower():
                return os.path.join(r,f)
    return None

def sign_apk(unsigned):
    al = "aligned.apk"; sg = "Installable_App.apk"
    try:
        subprocess.run(["zipalign","-v","-p","4",unsigned,al],
                       stdout=subprocess.DEVNULL,stderr=subprocess.DEVNULL,check=True)
        target = al
    except:
        target = unsigned
    generate_keystore()
    r = subprocess.run([
        "apksigner","sign","--ks","debug.keystore","--ks-pass","pass:android",
        "--out",sg,target
    ], capture_output=True, text=True)
    return sg if r.returncode == 0 else None

f = st.file_uploader("Project ZIP Upload Karein", type=["zip"])

if f is not None:
    if st.button("🔨 Create & Sign APK"):
        setup_java_env()  # Auto detect and set JAVA_HOME
        
        sts = st.empty(); bar = st.progress(0)
        if os.path.exists("project_extract"): shutil.rmtree("project_extract")
        os.makedirs("project_extract")
        sts.info("📦 ZIP extract ho raha hai...")
        with open("uploaded_project.zip","wb") as w: w.write(f.getbuffer())
        with zipfile.ZipFile("uploaded_project.zip","r") as z: z.extractall("project_extract")
        bar.progress(15)

        flutter_root = None; native_root = None
        for r,_,fs in os.walk("project_extract"):
            if "pubspec.yaml" in fs and not flutter_root: flutter_root = r
            if "gradlew" in fs and not native_root: native_root = r

        unsigned = None

        if flutter_root:
            sts.info("🟦 Flutter project — flutter build apk chal raha hai...")
            bar.progress(20)
            
            android_dir = os.path.join(flutter_root, "android")
            if not os.path.exists(android_dir):
                os.makedirs(android_dir)
                
            sdk_dir = os.environ.get('ANDROID_HOME', os.environ.get('ANDROID_SDK_ROOT', '/sdk'))
            flutter_dir = os.environ.get('FLUTTER_HOME', '/opt/flutter')

            with open(os.path.join(android_dir, "local.properties"), "w") as lf:
                lf.write(f"sdk.dir={sdk_dir}\n")
                lf.write(f"flutter.sdk={flutter_dir}\n")
                lf.write("flutter.buildMode=release\n")

            r1 = subprocess.run(["flutter","pub","get"], cwd=flutter_root, capture_output=True, text=True)
            if r1.returncode != 0:
                st.error("❌ flutter pub get fail!"); st.text(r1.stderr[-2000:])
            else:
                bar.progress(35)
                r2 = subprocess.run(["flutter","build","apk","--release"], cwd=flutter_root, capture_output=True, text=True)
                bar.progress(85)
                if r2.returncode == 0:
                    apk_dir = os.path.join(flutter_root,"build","app","outputs","flutter-apk")
                    unsigned = find_apk(apk_dir)
                else:
                    st.error("❌ Flutter Build Failed!")
                    st.text_area("Error Log", r2.stderr[-3000:], height=250)

        elif native_root:
            sts.info("🟩 Native Android project — gradlew assembleRelease chal raha hai...")
            bar.progress(20)
            
            sdk_dir = os.environ.get('ANDROID_HOME', os.environ.get('ANDROID_SDK_ROOT', '/sdk'))
            with open(os.path.join(native_root, "local.properties"), "w") as lf:
                lf.write(f"sdk.dir={sdk_dir}\n")

            subprocess.run(["chmod","+x",os.path.join(native_root,"gradlew")])
            bar.progress(25)
            r = subprocess.run(["./gradlew","assembleRelease","--no-daemon","--stacktrace"],
                               cwd=native_root, capture_output=True, text=True)
            bar.progress(85)
            if r.returncode == 0:
                unsigned = find_apk(native_root)
            else:
                st.error("❌ Gradle Build Failed!")
                st.text_area("Error Log", r.stderr[-3000:], height=250)
        else:
            st.error("❌ ZIP mein na pubspec.yaml mila, na gradlew.")

        if unsigned and os.path.exists(unsigned):
            sts.info("🔐 APK sign ho raha hai...")
            sg = sign_apk(unsigned)
            if sg:
                bar.progress(100); sts.success("🎉 APK Ready!")
                with open(sg,"rb") as dl:
                    st.download_button("⬇️ Download APK", data=dl, file_name=sg, mime="application/vnd.android.package-archive")
            else:
                st.error("Signing fail ho gayi.")

        if os.path.exists("uploaded_project.zip"): os.remove("uploaded_project.zip")