import os
import re
import json
import time
import unicodedata
import gc
from io import BytesIO
from typing import Iterable
from typing import Tuple, Optional, List, Dict, Any

import gradio as gr
import numpy as np
import torch
import spaces
from PIL import Image, ImageDraw, ImageFont

# Transformers & Qwen Utils
from transformers import (
    Qwen2_5_VLForConditionalGeneration,
    AutoProcessor,
    AutoModelForImageTextToText
)
from transformers.models.qwen2_vl.image_processing_qwen2_vl import smart_resize
from qwen_vl_utils import process_vision_info

# Gradio Theme
from gradio.themes import Soft
from gradio.themes.utils import colors, fonts, sizes

# -----------------------------------------------------------------------------
# 1. THEME CONFIGURATION
# -----------------------------------------------------------------------------

colors.steel_blue = colors.Color(
    name="steel_blue",
    c50="#EBF3F8",
    c100="#D3E5F0",
    c200="#A8CCE1",
    c300="#7DB3D2",
    c400="#529AC3",
    c500="#4682B4",
    c600="#3E72A0",
    c700="#36638C",
    c800="#2E5378",
    c900="#264364",
    c950="#1E3450",
)

class SteelBlueTheme(Soft):
    def __init__(
        self,
        *,
        primary_hue: colors.Color | str = colors.gray,
        secondary_hue: colors.Color | str = colors.steel_blue,
        neutral_hue: colors.Color | str = colors.slate,
        text_size: sizes.Size | str = sizes.text_lg,
        font: fonts.Font | str | Iterable[fonts.Font | str] = (
            fonts.GoogleFont("Outfit"), "Arial", "sans-serif",
        ),
        font_mono: fonts.Font | str | Iterable[fonts.Font | str] = (
            fonts.GoogleFont("IBM Plex Mono"), "ui-monospace", "monospace",
        ),
    ):
        super().__init__(
            primary_hue=primary_hue,
            secondary_hue=secondary_hue,
            neutral_hue=neutral_hue,
            text_size=text_size,
            font=font,
            font_mono=font_mono,
        )
        super().set(
            background_fill_primary="*primary_50",
            background_fill_primary_dark="*primary_900",
            body_background_fill="linear-gradient(135deg, *primary_200, *primary_100)",
            body_background_fill_dark="linear-gradient(135deg, *primary_900, *primary_800)",
            button_primary_text_color="white",
            button_primary_text_color_hover="white",
            button_primary_background_fill="linear-gradient(90deg, *secondary_500, *secondary_600)",
            button_primary_background_fill_hover="linear-gradient(90deg, *secondary_600, *secondary_700)",
            button_primary_background_fill_dark="linear-gradient(90deg, *secondary_600, *secondary_800)",
            button_primary_background_fill_hover_dark="linear-gradient(90deg, *secondary_500, *secondary_500)",
            block_title_text_weight="600",
            block_border_width="3px",
            block_shadow="*shadow_drop_lg",
            button_primary_shadow="*shadow_drop_lg",
            button_large_padding="11px",
        )

steel_blue_theme = SteelBlueTheme()
css = "#main-title h1 { font-size: 2.3em !important; } #out_img { height: 600px; object-fit: contain; }"

# -----------------------------------------------------------------------------
# 2. GLOBAL MODEL LOADING
# -----------------------------------------------------------------------------

device = "cuda" if torch.cuda.is_available() else "cpu"
print(f"Running on device: {device}")

# --- Load Fara-7B ---
print("🔄 Loading Fara-7B...")
MODEL_ID_V = "microsoft/Fara-7B"
try:
    processor_v = AutoProcessor.from_pretrained(MODEL_ID_V, trust_remote_code=True)
    model_v = Qwen2_5_VLForConditionalGeneration.from_pretrained(
        MODEL_ID_V,
        trust_remote_code=True,
        torch_dtype=torch.float16
    ).to(device).eval()
except Exception as e:
    print(f"Failed to load Fara: {e}")
    model_v = None
    processor_v = None

# --- Load UI-TARS-1.5-7B ---
print("🔄 Loading UI-TARS-1.5-7B...")
MODEL_ID_X = "ByteDance-Seed/UI-TARS-1.5-7B"
try:
    # Important: use_fast=False is often required for custom tokenizers
    processor_x = AutoProcessor.from_pretrained(MODEL_ID_X, trust_remote_code=True, use_fast=False)
    model_x = AutoModelForImageTextToText.from_pretrained(
        MODEL_ID_X,
        trust_remote_code=True,
        torch_dtype=torch.bfloat16 if device == "cuda" else torch.float32,
    ).to(device).eval()
except Exception as e:
    print(f"Failed to load UI-TARS: {e}")
    model_x = None
    processor_x = None

# --- Load Holo2-8B ---
print("🔄 Loading Holo2-8B...")
MODEL_ID_H = "Hcompany/Holo2-8B"
try:
    processor_h = AutoProcessor.from_pretrained(MODEL_ID_H, trust_remote_code=True)
    model_h = AutoModelForImageTextToText.from_pretrained(
        MODEL_ID_H,
        trust_remote_code=True,
        torch_dtype=torch.float16
    ).to(device).eval()
except Exception as e:
    print(f"Failed to load Holo2-8B: {e}")
    model_h = None
    processor_h = None

print("✅ Models loading sequence complete.")


# -----------------------------------------------------------------------------
# 3. UTILS & PROMPTS
# -----------------------------------------------------------------------------

def array_to_image(image_array: np.ndarray) -> Image.Image:
    if image_array is None: raise ValueError("No image provided.")
    return Image.fromarray(np.uint8(image_array))

# --- Fara Prompt ---
def get_fara_prompt(task, image):
    OS_SYSTEM_PROMPT = """You are a GUI agent. You are given a task and a screenshot of the current status.
    You need to generate the next action to complete the task.
    Output your action inside a <tool_call> block using JSON format.
    Include "coordinate": [x, y] in pixels for interactions.
    Examples:
    <tool_call>{"name": "User", "arguments": {"action": "click", "coordinate": [400, 300]}}</tool_call>
    <tool_call>{"name": "User", "arguments": {"action": "type", "coordinate": [100, 200], "text": "hello"}}</tool_call>
    """
    return [
        {"role": "system", "content": [{"type": "text", "text": OS_SYSTEM_PROMPT}]},
        {"role": "user", "content": [{"type": "image", "image": image}, {"type": "text", "text": f"Instruction: {task}"}]},
    ]

# --- UI-TARS & Holo Prompt ---
def get_localization_prompt(task, image):
    guidelines = (
        "Localize an element on the GUI image according to my instructions and "
        "output a click position as Click(x, y) with x num pixels from the left edge "
        "and y num pixels from the top edge."
    )
    return [
        {
            "role": "user",
            "content": [
                {"type": "image", "image": image},
                {"type": "text", "text": f"{guidelines}\n{task}"}
            ],
        }
    ]

def get_image_proc_params(processor) -> Dict[str, int]:
    ip = getattr(processor, "image_processor", None)
    return {
        "patch_size": getattr(ip, "patch_size", 14),
        "merge_size": getattr(ip, "merge_size", 2),
        "min_pixels": getattr(ip, "min_pixels", 256 * 256),
        "max_pixels": getattr(ip, "max_pixels", 1280 * 1280),
    }

# --- Chat/template helpers ---
def apply_chat_template_compat(processor, messages: List[Dict[str, Any]]) -> str:
    tok = getattr(processor, "tokenizer", None)
    if hasattr(processor, "apply_chat_template"):
        return processor.apply_chat_template(messages, tokenize=False, add_generation_prompt=True)
    if tok is not None and hasattr(tok, "apply_chat_template"):
        return tok.apply_chat_template(messages, tokenize=False, add_generation_prompt=True)
    # Fallback for older models
    texts = []
    for m in messages:
        if isinstance(m.get("content"), list):
            for c in m.get("content", []):
                if isinstance(c, dict) and c.get("type") == "text":
                    texts.append(c.get("text", ""))
        elif isinstance(m.get("content"), str):
             texts.append(m.get("content"))
    return "\n".join(texts)

def batch_decode_compat(processor, token_id_batches, **kw):
    tok = getattr(processor, "tokenizer", None)
    if hasattr(processor, "batch_decode"):
        return processor.batch_decode(token_id_batches, **kw)
    if tok is not None and hasattr(tok, "batch_decode"):
        return tok.batch_decode(token_id_batches, **kw)
    raise AttributeError("No batch_decode available on processor or tokenizer.")

def trim_generated(generated_ids, inputs):
    in_ids = getattr(inputs, "input_ids", None)
    if in_ids is None and isinstance(inputs, dict):
        in_ids = inputs.get("input_ids", None)
    if in_ids is None:
        return generated_ids
    return [out_ids[len(in_seq):] for in_seq, out_ids in zip(in_ids, generated_ids)]


# -----------------------------------------------------------------------------
# 4. PARSING LOGIC
# -----------------------------------------------------------------------------

def parse_click_response(text: str) -> List[Dict]:
    """Parse various 'Click(x, y)' style formats from models like UI-TARS and Holo."""
    actions = []
    text = text.strip()

    print(f"Parsing click-style output: {text}")

    # Regex 1: Click(x, y) - Standard prompt output
    matches_click = re.findall(r"Click\s*\(\s*(\d+)\s*,\s*(\d+)\s*\)", text, re.IGNORECASE)
    for m in matches_click:
        actions.append({"type": "click", "x": int(m[0]), "y": int(m[1]), "text": ""})

    # Regex 2: point=[x, y] - Common model internal format
    matches_point = re.findall(r"point=\[\s*(\d+)\s*,\s*(\d+)\s*\]", text, re.IGNORECASE)
    for m in matches_point:
        actions.append({"type": "click", "x": int(m[0]), "y": int(m[1]), "text": ""})

    # Regex 3: start_box='(x, y)' - Another variant
    matches_box = re.findall(r"start_box=['\"]?\(\s*(\d+)\s*,\s*(\d+)\s*\)['\"]?", text, re.IGNORECASE)
    for m in matches_box:
        actions.append({"type": "click", "x": int(m[0]), "y": int(m[1]), "text": ""})

    # Remove duplicates
    unique_actions = []
    seen = set()
    for a in actions:
        key = (a['type'], a['x'], a['y'])
        if key not in seen:
            seen.add(key)
            unique_actions.append(a)
            
    return unique_actions

def parse_fara_response(response: str) -> List[Dict]:
    """Parse Fara <tool_call> JSON format"""
    actions = []
    matches = re.findall(r"<tool_call>(.*?)</tool_call>", response, re.DOTALL)
    for match in matches:
        try:
            data = json.loads(match.strip())
            args = data.get("arguments", {})
            coords = args.get("coordinate", [])
            action_type = args.get("action", "unknown")
            text_content = args.get("text", "")
            if coords and len(coords) == 2:
                actions.append({
                    "type": action_type, "x": float(coords[0]), "y": float(coords[1]), "text": text_content
                })
        except Exception as e:
            print(f"Error parsing Fara JSON: {e}")
            pass
    return actions

def create_localized_image(original_image: Image.Image, actions: list[dict]) -> Optional[Image.Image]:
    if not actions: return None
    img_copy = original_image.copy()
    draw = ImageDraw.Draw(img_copy)
    width, height = img_copy.size
    
    try:
        font = ImageFont.load_default(size=20)
    except IOError:
        font = ImageFont.load_default()
    
    for act in actions:
        x = act['x']
        y = act['y']
        
        # Coordinates should already be scaled to the original image size
        pixel_x, pixel_y = int(x), int(y)
            
        color = 'red' if 'click' in act['type'].lower() else 'blue'
        
        # Draw Target Crosshair/Circle
        r = 20
        line_width = 5
        
        # Circle
        draw.ellipse([pixel_x - r, pixel_y - r, pixel_x + r, pixel_y + r], outline=color, width=line_width)
        # Center dot
        draw.ellipse([pixel_x - 4, pixel_y - 4, pixel_x + 4, pixel_y + 4], fill=color)
        
        # Label
        label = f"{act['type'].capitalize()}"
        if act.get('text'): label += f": \"{act['text']}\""
        
        text_pos = (pixel_x + 25, pixel_y - 15)
        
        # Draw text with background
        try:
            bbox = draw.textbbox(text_pos, label, font=font)
            draw.rectangle((bbox[0]-5, bbox[1]-3, bbox[2]+5, bbox[3]+3), fill="rgba(0,0,0,180)")
            draw.text(text_pos, label, fill="white", font=font)
        except Exception as e:
            print(f"Error drawing text: {e}")
            # Fallback if font loading/drawing fails
            draw.text(text_pos, label, fill="white")

    return img_copy

# -----------------------------------------------------------------------------
# 5. CORE LOGIC
# -----------------------------------------------------------------------------

@spaces.GPU(duration=120)
def process_screenshot(input_numpy_image: np.ndarray, task: str, model_choice: str):
    if input_numpy_image is None: return "⚠️ Please upload an image.", None
    if not task.strip(): return "⚠️ Please provide a task instruction.", None

    input_pil_image = array_to_image(input_numpy_image)
    orig_w, orig_h = input_pil_image.size
    actions = []
    raw_response = ""

    # --- Fara Logic ---
    if model_choice == "Fara-7B":
        if model_v is None: return "Error: Fara model failed to load on startup.", None
        print("Using Fara Pipeline...")
        messages = get_fara_prompt(task, input_pil_image)
        text_prompt = processor_v.apply_chat_template(messages, tokenize=False, add_generation_prompt=True)
        image_inputs, video_inputs = process_vision_info(messages)

        inputs = processor_v(
            text=[text_prompt],
            images=image_inputs,
            videos=video_inputs,
            padding=True,
            return_tensors="pt"
        )
        inputs = inputs.to(device)
        
        with torch.no_grad():
            generated_ids = model_v.generate(**inputs, max_new_tokens=512)
            
        generated_ids = trim_generated(generated_ids, inputs)
        raw_response = processor_v.batch_decode(generated_ids, skip_special_tokens=True)[0]
        
        actions = parse_fara_response(raw_response)

    # --- UI-TARS or Holo Logic ---
    else:
        if model_choice == "UI-TARS-1.5-7B":
            model, processor = model_x, processor_x
            if model is None: return "Error: UI-TARS model failed to load.", None
            print("Using UI-TARS Pipeline...")
        elif model_choice == "Holo2-8B":
            model, processor = model_h, processor_h
            if model is None: return "Error: Holo2-8B model failed to load.", None
            print("Using Holo2-8B Pipeline...")
        else:
            return f"Error: Unknown model '{model_choice}'", None

        # 1. Smart Resize (Crucial for accuracy)
        ip_params = get_image_proc_params(processor)
        resized_h, resized_w = smart_resize(
            input_pil_image.height, input_pil_image.width,
            factor=ip_params["patch_size"] * ip_params["merge_size"],
            min_pixels=ip_params["min_pixels"], max_pixels=ip_params["max_pixels"]
        )
        proc_image = input_pil_image.resize((resized_w, resized_h), Image.Resampling.LANCZOS)
        
        # 2. Prompting
        messages = get_localization_prompt(task, proc_image)
        text_prompt = apply_chat_template_compat(processor, messages)
        
        # 3. Inputs
        inputs = processor(text=[text_prompt], images=[proc_image], padding=True, return_tensors="pt")
        inputs = {k: v.to(device) for k, v in inputs.items()}
        
        # 4. Generate
        with torch.no_grad():
            generated_ids = model.generate(**inputs, max_new_tokens=128)
            
        generated_ids = trim_generated(generated_ids, inputs)
        raw_response = batch_decode_compat(processor, generated_ids, skip_special_tokens=True)[0]
        
        # 5. Parse
        actions = parse_click_response(raw_response)
        
        # 6. Rescale Coordinates back to Original Image Size
        if resized_w > 0 and resized_h > 0:
            scale_x = orig_w / resized_w
            scale_y = orig_h / resized_h
            for a in actions:
                a['x'] = int(a['x'] * scale_x)
                a['y'] = int(a['y'] * scale_y)

    print(f"Raw Output: {raw_response}")
    print(f"Parsed Actions: {actions}")

    # Visualize
    output_image = input_pil_image
    if actions:
        vis = create_localized_image(input_pil_image, actions)
        if vis: output_image = vis
            
    return raw_response, output_image

# -----------------------------------------------------------------------------
# 6. UI SETUP
# -----------------------------------------------------------------------------

with gr.Blocks(theme=steel_blue_theme, css=css) as demo:
    gr.Markdown("# **CUA GUI Agent 🖥️**", elem_id="main-title")
    gr.Markdown("Upload a screenshot, select a model, and provide a task. The model will determine the precise UI coordinates and actions.")

    with gr.Row():
        with gr.Column(scale=2):
            input_image = gr.Image(label="Upload Screenshot", type="numpy", height=500)
            
            with gr.Row():
                model_choice = gr.Radio(
                    choices=["Fara-7B", "UI-TARS-1.5-7B", "Holo2-8B"],
                    label="Select Model",
                    value="Fara-7B",
                    interactive=True
                )
            
            task_input = gr.Textbox(
                label="Task Instruction",
                placeholder="e.g. Click on the search bar and type 'hello world'",
                lines=2
            )
            submit_btn = gr.Button("Analyze UI & Generate Action", variant="primary")

        with gr.Column(scale=3):
            output_image = gr.Image(label="Visualized Action Points", elem_id="out_img", height=500)
            output_text = gr.Textbox(label="Raw Model Output", lines=8, show_copy_button=True)

    submit_btn.click(
        fn=process_screenshot,
        inputs=[input_image, task_input, model_choice],
        outputs=[output_text, output_image]
    )
    
    gr.Examples(
        examples=[
            ["./assets/google.png", "Search for 'Hugging Face'", "Fara-7B"],
            ["./assets/google.png", "Click the microphone button", "UI-TARS-1.5-7B"],
            ["./assets/google.png", "Where is the 'I'm Feeling Lucky' button?", "Holo2-8B"],
        ],
        inputs=[input_image, task_input, model_choice],
        label="Quick Examples"
    )

if __name__ == "__main__":
    demo.queue().launch()