import gradio as gr
from PIL import Image, ImageOps, ImageDraw, ImageFont
import requests
import io
import json
import logging
import os
import struct
import tempfile
import random
from cryptography.hazmat.primitives import serialization
from cryptography.hazmat.primitives.asymmetric import rsa, padding
from cryptography.hazmat.primitives.ciphers.aead import AESGCM
from cryptography.hazmat.primitives import hashes
import numpy as np

logging.basicConfig(level=logging.INFO, format='%(asctime)s - %(name)s - %(levelname)s - %(message)s')
PREFERRED_FONTS = ["Arial", "Helvetica", "DejaVu Sans", "Verdana", "Calibri", "sans-serif"]

class AppServerLogic:
    def __init__(self):
        self.private_key_object = None
        self.public_key_pem = ""
        self._initialize_keys()

    def _initialize_keys(self):
        key_pem = os.environ.get('KEYLOCK_PRIV_KEY')
        if not key_pem:
            pk = rsa.generate_private_key(public_exponent=65537, key_size=2048)
            key_pem = pk.private_bytes(encoding=serialization.Encoding.PEM, format=serialization.PrivateFormat.PKCS8, encryption_algorithm=serialization.NoEncryption()).decode('utf-8')
        try:
            self.private_key_object = serialization.load_pem_private_key(key_pem.encode(), password=None)
            self.public_key_pem = self.private_key_object.public_key().public_bytes(encoding=serialization.Encoding.PEM, format=serialization.PublicFormat.SubjectPublicKeyInfo).decode('utf-8')
        except Exception as e:
            logging.error(f"Key initialization failed: {e}")

    def decode_payload(self, image_input):
        if not self.private_key_object:
            return {"status": "Error", "message": "Server key not configured."}
        try:
            pixel_data = np.array(image_input.convert("RGB")).ravel()
            header_binary = "".join(str(p & 1) for p in pixel_data[:32])
            data_length = int(header_binary, 2)
            required_pixels = 32 + data_length * 8
            if required_pixels > len(pixel_data):
                raise ValueError("Incomplete payload in image.")
            data_binary = "".join(str(p & 1) for p in pixel_data[32:required_pixels])
            crypto_payload = int(data_binary, 2).to_bytes(data_length, byteorder='big')
            offset = 4
            encrypted_aes_key_len = struct.unpack('>I', crypto_payload[:offset])[0]
            encrypted_aes_key = crypto_payload[offset:offset + encrypted_aes_key_len]; offset += encrypted_aes_key_len
            nonce = crypto_payload[offset:offset + 12]; offset += 12
            ciphertext = crypto_payload[offset:]
            recovered_aes_key = self.private_key_object.decrypt(encrypted_aes_key, padding.OAEP(mgf=padding.MGF1(hashes.SHA256()), algorithm=hashes.SHA256(), label=None))
            payload = json.loads(AESGCM(recovered_aes_key).decrypt(nonce, ciphertext, None).decode())
            return {"status": "Success", "payload": payload}
        except Exception as e:
            return {"status": "Error", "message": f"Decryption Failed: {e}"}

    @staticmethod
    def _get_font(preferred_fonts, base_size):
        fp = None
        for n in preferred_fonts:
            try: ImageFont.truetype(n.lower()+".ttf", 10); fp = n.lower()+".ttf"; break
            except IOError: continue
        if fp: return ImageFont.truetype(fp, base_size)
        return ImageFont.load_default(size=base_size)

    @staticmethod
    def _generate_starfield_image(w=800, h=800):
        center_x, center_y = w / 2, h / 2
        y_coords, x_coords = np.mgrid[0:h, 0:w]
        distance = np.sqrt((x_coords - center_x)**2 + (y_coords - center_y)**2)
        max_distance = np.sqrt(center_x**2 + center_y**2)
        distance_norm = distance / max_distance
        bg_center_color = np.array([20, 25, 40])
        bg_outer_color = np.array([0, 0, 5])
        gradient = bg_outer_color + (bg_center_color - bg_outer_color) * (1 - distance_norm[..., np.newaxis])
        img = Image.fromarray(gradient.astype(np.uint8), 'RGB')
        draw = ImageDraw.Draw(img)
        for _ in range(int((w * h) / 200)):
            x, y = random.randint(0, w - 1), random.randint(0, h - 1)
            brightness = random.randint(30, 90)
            draw.point((x, y), fill=(int(brightness*0.9), int(brightness*0.9), brightness))
        star_colors = [(255, 255, 255), (220, 230, 255), (255, 240, 220)]
        for _ in range(int((w * h) / 1000)):
            x, y = random.randint(0, w - 1), random.randint(0, h - 1)
            size = 0.5 + (2.5 * (random.random() ** 2))
            brightness = 120 + (135 * (random.random() ** 1.5))
            color = random.choice(star_colors)
            final_color = tuple(int(c * (brightness / 255.0)) for c in color)
            glow_size = size * 3
            glow_color = tuple(int(c * 0.3) for c in final_color)
            draw.ellipse([x - glow_size, y - glow_size, x + glow_size, y + glow_size], fill=glow_color)
            draw.ellipse([x - size, y - size, x + size, y + size], fill=final_color)
        return img

    def _draw_overlay(self, image: Image.Image) -> Image.Image:
        img_overlayed = image.copy().convert("RGBA")
        draw = ImageDraw.Draw(img_overlayed, "RGBA")
        width, height = img_overlayed.size
        overlay_color = (10, 15, 30, 200)
        title_color = (200, 220, 255)
        font_bold = self._get_font(PREFERRED_FONTS, 30)
        draw.rectangle([0, 20, width, 80], fill=overlay_color)
        draw.text((width / 2, 50), "KeyLock Secure Data", fill=title_color, font=font_bold, anchor="ms")
        final_image_rgb = Image.new("RGB", img_overlayed.size, (0, 0, 0))
        final_image_rgb.paste(img_overlayed, (0, 0), img_overlayed)
        return final_image_rgb

    def generate_encrypted_image(self, payload_dict):
        base_image = self._generate_starfield_image()
        image_with_overlay = self._draw_overlay(base_image)
        json_bytes = json.dumps(payload_dict).encode('utf-8')
        public_key = serialization.load_pem_public_key(self.public_key_pem.encode('utf-8'))
        aes_key, nonce = os.urandom(32), os.urandom(12)
        ciphertext = AESGCM(aes_key).encrypt(nonce, json_bytes, None)
        rsa_key = public_key.encrypt(aes_key, padding.OAEP(mgf=padding.MGF1(hashes.SHA256()), algorithm=hashes.SHA256(), label=None))
        payload = struct.pack('>I', len(rsa_key)) + rsa_key + nonce + ciphertext
        pixel_data = np.array(image_with_overlay).ravel()
        binary_payload = ''.join(format(b, '08b') for b in struct.pack('>I', len(payload)) + payload)
        pixel_data[:len(binary_payload)] = (pixel_data[:len(binary_payload)] & 0xFE) | np.array(list(binary_payload), dtype=np.uint8)
        final_image = Image.fromarray(pixel_data.reshape(image_with_overlay.size[1], image_with_overlay.size[0], 3), 'RGB')
        
        with tempfile.NamedTemporaryFile(suffix=".png", delete=False) as f:
            final_image.save(f.name, "PNG")
            return f.name, f.name

    @staticmethod
    def generate_pem_keys():
        pk = rsa.generate_private_key(public_exponent=65537, key_size=2048)
        priv = pk.private_bytes(encoding=serialization.Encoding.PEM, format=serialization.PrivateFormat.PKCS8, encryption_algorithm=serialization.NoEncryption()).decode()
        pub = pk.public_key().public_bytes(encoding=serialization.Encoding.PEM, format=serialization.PublicFormat.SubjectPublicKeyInfo).decode()
        return priv, pub

class KeylockDecoderComponent(gr.components.Component):
    EVENTS = ["change"]

    def __init__(self, server_logic, **kwargs):
        self.server_logic = server_logic
        self.value = None
        super().__init__(value=self.value, **kwargs)

    def _format_message(self, result: dict | None) -> str:
        if not result or not result.get("status"): return "Upload a KeyLock image to auto-fill credentials."
        status = result["status"]
        if status == "Success":
            user = result.get("payload", {}).get("USER", "N/A")
            return f"<p style='color:green; font-weight:bold;'>✅ Success! Decoded credentials for '{user}'.</p>"
        else:
            message = result.get("message", "An unknown error occurred.")
            return f"<p style='color:red; font-weight:bold;'>❌ Error: {message}</p>"

    def preprocess(self, payload): return payload
    def postprocess(self, value): return value
    def api_info(self): return {"type": "object", "example": {"status": "Success", "payload": {"USER": "demo-user"}}}

    def render(self):
        value_state = gr.State(value=self.value)
        
        with gr.Column():
            image_input = gr.Image(label="KeyLock Image", type="pil", show_label=False)
            status_display = gr.Markdown(self._format_message(self.value))
            with gr.Accordion("Generate Encrypted Image", open=False):
                payload_input = gr.JSON(label="Payload to Encrypt", value={"API_KEY": "sk-12345-abcde", "USER": "demo-user"})
                generate_img_button = gr.Button("Generate Image", variant="secondary")
                generated_image_preview = gr.Image(label="Generated Image Preview", type="filepath", interactive=False)
                generated_file_download = gr.File(label="Download Uncorrupted PNG", interactive=False)
            with gr.Accordion("Create New Standalone Key Pair", open=False):
                generate_keys_button = gr.Button("Generate Keys", variant="secondary")
                with gr.Row():
                    output_private_key = gr.Code(label="Generated Private Key", language="python")
                    output_public_key = gr.Code(label="Generated Public Key", language="python")

        def on_image_upload(image):
            if image is None: return None, "Upload a KeyLock image to auto-fill credentials."
            result_dict = self.server_logic.decode_payload(image)
            formatted_message = self._format_message(result_dict)
            return result_dict, formatted_message

        image_input.upload(fn=on_image_upload, inputs=[image_input], outputs=[value_state, status_display])
        generate_img_button.click(fn=self.server_logic.generate_encrypted_image, inputs=[payload_input], outputs=[generated_image_preview, generated_file_download])
        generate_keys_button.click(fn=self.server_logic.generate_pem_keys, inputs=None, outputs=[output_private_key, output_public_key])
        
        return {"value": value_state}