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

# Page Config
st.set_page_config(page_title="Android Build Server", layout="centered")

st.title("📱 Android APK Generator (Final Production)")
st.markdown("Zip upload karein. Server APK banayega aur **Auto-Sign** karega.")

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

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

if uploaded_file is not None:
    if st.button("🔨 Create & Sign APK"):
        status_text = st.empty()
        progress_bar = st.progress(0)
        
        # 1. Cleanup
        if os.path.exists("project_extract"):
            shutil.rmtree("project_extract")
        os.makedirs("project_extract", exist_ok=True)
        
        # 2. Extract
        status_text.info("Extracting ZIP file...")
        with open("uploaded_project.zip", "wb") as f:
            f.write(uploaded_file.getbuffer())
        with zipfile.ZipFile("uploaded_project.zip", "r") as zip_ref:
            zip_ref.extractall("project_extract")
        progress_bar.progress(20)
        
        # 3. Find Root
        project_root = None
        for root, dirs, files in os.walk("project_extract"):
            if "gradlew" in files:
                project_root = root
                break
        
        if not project_root:
            st.error("❌ ZIP file mein 'gradlew' nahi mila.")
        else:
            # 4. Permissions
            status_text.info("Setting up Gradle...")
            gradlew_path = os.path.join(project_root, "gradlew")
            subprocess.run(["chmod", "+x", gradlew_path])
            
            # 5. Build
            status_text.info("Building APK... (Wait karein)")
            # Hum assembleRelease chala rahe hain
            build_cmd = ["./gradlew", "assembleRelease", "--no-daemon", "--stacktrace"]
            
            try:
                result = subprocess.run(
                    build_cmd,
                    cwd=project_root,
                    stdout=subprocess.PIPE,
                    stderr=subprocess.PIPE,
                    text=True
                )
                
                progress_bar.progress(60)
                
                if result.returncode == 0:
                    status_text.info("✅ Build Successful! Signing APK...")
                    
                    # 6. Find Unsigned APK
                    unsigned_apk = None
                    for root, dirs, files in os.walk(project_root):
                        for file in files:
                            if file.endswith(".apk") and "release" in file:
                                unsigned_apk = os.path.join(root, file)
                                break
                    
                    if unsigned_apk:
                        # 7. SIGNING (Direct System Commands)
                        keystore = generate_keystore()
                        signed_apk_name = "Installable_App.apk"
                        aligned_apk = "aligned.apk"

                        # Step A: ZipAlign (Important for installation)
                        try:
                            subprocess.run(["zipalign", "-v", "-p", "4", unsigned_apk, aligned_apk], 
                                           stdout=subprocess.DEVNULL, check=True)
                            apk_to_sign = aligned_apk
                        except:
                            # Agar align fail ho, to original use kar lo
                            apk_to_sign = unsigned_apk

                        # Step B: APKSigner
                        sign_cmd = [
                            "apksigner", "sign",
                            "--ks", keystore,
                            "--ks-pass", "pass:android",
                            "--out", signed_apk_name,
                            apk_to_sign
                        ]
                        
                        sign_result = subprocess.run(sign_cmd, capture_output=True, text=True)
                        
                        if sign_result.returncode == 0:
                            status_text.success("🎉 APK Signed & Ready to Install!")
                            progress_bar.progress(100)
                            
                            with open(signed_apk_name, "rb") as f:
                                st.download_button(
                                    label="⬇️ Download Installable APK",
                                    data=f,
                                    file_name=signed_apk_name,
                                    mime="application/vnd.android.package-archive"
                                )
                        else:
                            st.error("Build hui magar Signing fail hogayi.")
                            st.text_area("Signing Log", sign_result.stderr)
                    else:
                        st.error("APK file generate nahi hui.")
                        
                else:
                    st.error("❌ Build Failed!")
                    st.text_area("Error Log", result.stderr, height=300)
                    
            except Exception as e:
                st.error(f"System Error: {str(e)}")

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