# backend.py

import json
import threading
import queue
from collections import deque
from dataclasses import dataclass, field
from typing import Dict, Optional, Tuple
from playwright._impl._api_structures import StorageState

import cv2
import numpy as np
from playwright.sync_api import sync_playwright, Page, BrowserContext
from playwright_stealth import Stealth
from PIL import Image, ImageDraw
from io import BytesIO

# ─────────────────────────────
# Global Queues (worker <-> UI)
# ─────────────────────────────
task_queue: "queue.Queue[dict]" = queue.Queue()
result_queue: "queue.Queue[Tuple[str, Optional[Image.Image]]]" = queue.Queue()

# ─────────────────────────────
# Browser State + Lock
# ─────────────────────────────

@dataclass
class BrowserState:
    running: bool = False
    thread: Optional[threading.Thread] = None
    pages: Dict[str, Page] = field(default_factory=dict)  # tab_name -> Page
    active_page: Optional[str] = None
    network_logs: deque = field(default_factory=lambda: deque(maxlen=500))
    console_logs: deque = field(default_factory=lambda: deque(maxlen=500))
    recording: bool = False
    macro: list = field(default_factory=list)
    tab_counter: int = 0  # to generate stable names


BROWSER_STATE = BrowserState()
BROWSER_LOCK = threading.Lock()


# ─────────────────────────────
# Helper: Safe screenshot
# ─────────────────────────────

def take_screenshot(page: Optional[Page]) -> Optional[Image.Image]:
    if page is None:
        return None
    try:
        img_bytes = page.screenshot()
        return Image.open(BytesIO(img_bytes))
    except Exception:
        return None


# ─────────────────────────────
# Worker Class (Playwright)
# ─────────────────────────────

class PlaywrightWorker:
    def __init__(self, state: BrowserState, storage_state: StorageState=None):
        self.state = state
        self.context: Optional[BrowserContext] = None
        self.storage_state = storage_state
    # ---- Main loop ----
    def run(self):
        with Stealth().use_sync(sync_playwright()) as p:
            browser = p.chromium.launch(headless=True, args=["--no-sandbox"])
            self.context = browser.new_context(storage_state=self.storage_state)
            self._attach_network_listeners(self.context)

            # default first tab
            self._create_new_tab()

            # Command dispatcher
            handlers = {
                "eval": self.handle_eval,
                "goto": self.handle_goto,
                "click": self.handle_click,
                "click_xy": self.handle_click_xy,
                "type": self.handle_type,
                "new_tab": self.handle_new_tab,
                "close_tab": self.handle_close_tab,
                "switch_tab": self.handle_switch_tab,
                "inspect": self.handle_inspect,
                "get_network_logs": self.handle_get_network_logs,
                "get_console_logs": self.handle_get_console_logs,
                "clear_logs": self.handle_clear_logs,
                "start_record": self.handle_start_record,
                "stop_record": self.handle_stop_record,
                "play_macro": self.handle_play_macro,
                "take_screenshot": self.handle_take_screenshot,
                "find_template": self.handle_find_template,
            }

            while True:
                task = task_queue.get()
                cmd = task.get("cmd")

                if cmd == "__EXIT__":
                    break

                result_text = ""
                screenshot = None

                try:
                    page = self._get_active_page()

                    # macro recording (xy-click ko record nahi kar rahe)
                    recordable_cmds = {
                        "goto", "click", "type", "new_tab",
                        "close_tab", "switch_tab"
                    }
                    if (
                        not task.get("from_macro", False)
                        and cmd in recordable_cmds
                    ):
                        with BROWSER_LOCK:
                            if self.state.recording:
                                rec = {k: v for k, v in task.items() if k != "from_macro"}
                                self.state.macro.append(rec)

                    handler = handlers.get(cmd, None)
                    if handler is None:
                        result_text = f"Unknown command: {cmd}"
                        screenshot = take_screenshot(page)
                    else:
                        result_text, screenshot = handler(task, page)

                except Exception as e:
                    result_text = f"Error: {type(e).__name__}: {e}"

                result_queue.put((result_text, screenshot))

            # graceful shutdown
            try:
                browser.close()
            except Exception:
                pass

    # ---- Console & Network hooks ----
    def _attach_console_listener(self, page: Page):
        def on_console(msg):
            with BROWSER_LOCK:
                self.state.console_logs.append(f"[{msg.type}] {msg.text}")
        page.on("console", on_console)

    def _attach_network_listeners(self, context: BrowserContext):
        def on_request(request):
            with BROWSER_LOCK:
                self.state.network_logs.append(f"[REQUEST] {request.method} {request.url}")

        def on_response(response):
            with BROWSER_LOCK:
                self.state.network_logs.append(f"[RESPONSE] {response.status} {response.url}")

        context.on("request", on_request)
        context.on("response", on_response)

    # ---- Tabs Management helpers ----
    def _create_new_tab(self) -> Tuple[str, Page]:
        page = self.context.new_page()
        with BROWSER_LOCK:
            self.state.tab_counter += 1
            tab_name = f"Tab-{self.state.tab_counter}"
            self.state.pages[tab_name] = page
            self.state.active_page = tab_name
        self._attach_console_listener(page)
        return tab_name, page

    def _get_active_page(self) -> Optional[Page]:
        with BROWSER_LOCK:
            name = self.state.active_page
            page = self.state.pages.get(name) if name else None
        return page

    # ─────────────────────────────
    # Command Handlers
    # ─────────────────────────────

    def handle_eval(self, task: dict, page: Optional[Page]):
        if page is None:
            return "No active page.", None

        code = task.get("code", "")
        safe_globals = {"__builtins__": {}}
        safe_locals = {}

        try:
            result = eval(code, safe_globals, safe_locals)
        except Exception as e:
            return f"Eval error: {type(e).__name__}: {e}", take_screenshot(page)

        text = f"Eval result: {result!r}"
        return text, take_screenshot(page)

    def handle_goto(self, task: dict, page: Optional[Page]):
        if page is None:
            return "No active page.", None
        url = task.get("url", "")
        try:
            page.goto(url)
            return f"Navigated to {url}", take_screenshot(page)
        except Exception as e:
            return f"Goto error: {e}", take_screenshot(page)

    def handle_click(self, task: dict, page: Optional[Page]):
        """
        CSS Selector Based Click (NOT XY click)
        Used for:
        • Normal click button
        • Macro playback
        """
        if page is None:
            return "No active page.", None

        selector = task.get("selector", "")
        if not selector:
            return "No selector provided.", take_screenshot(page)

        try:
            page.wait_for_selector(selector, timeout=5000)
            page.click(selector)
            return f"Clicked selector: {selector}", take_screenshot(page)

        except Exception as e:
            return f"Click error on '{selector}': {e}", take_screenshot(page)

    def handle_click_xy(self, task: dict, page: Optional[Page]):
        if page is None:
            return "No active page.", None

        x = task.get("x")
        y = task.get("y")
        img_w = task.get("img_w")
        img_h = task.get("img_h")
        click_type = task.get("click_type", "left")

        # viewport size
        vp = page.viewport_size or {"width": img_w, "height": img_h}

        real_x = x * (vp["width"] / img_w)
        real_y = y * (vp["height"] / img_h)

        if click_type == "left":
            page.mouse.click(real_x, real_y)
        elif click_type == "double":
            page.mouse.dblclick(real_x, real_y)
        elif click_type == "right":
            page.mouse.click(real_x, real_y, button="right")
        elif click_type == "hover":
            page.mouse.move(real_x, real_y)

        return f"{click_type} click at {real_x},{real_y}", take_screenshot(page)

    def handle_type(self, task: dict, page: Optional[Page]):
        if page is None:
            return "No active page.", None
        selector = task.get("selector", "")
        text = task.get("text", "")
        try:
            page.fill(selector, text)
            return f"Typed into {selector}: {text}", take_screenshot(page)
        except Exception as e:
            return f"Type error: {e}", take_screenshot(page)

    def handle_new_tab(self, task: dict, page: Optional[Page]):
        tab_name, new_page = self._create_new_tab()
        return f"Opened new tab: {tab_name}", take_screenshot(new_page)

    def handle_close_tab(self, task: dict, page: Optional[Page]):
        name = task.get("tab", "")
        with BROWSER_LOCK:
            if name in self.state.pages:
                try:
                    self.state.pages[name].close()
                except Exception:
                    pass
                del self.state.pages[name]
                msg = f"Closed {name}"
                if self.state.active_page == name:
                    if self.state.pages:
                        self.state.active_page = list(self.state.pages.keys())[0]
                    else:
                        self.state.active_page = None
            else:
                msg = f"Tab {name} not found."

            active_name = self.state.active_page
            active_page = self.state.pages.get(active_name) if active_name else None

        return msg, take_screenshot(active_page)

    def handle_switch_tab(self, task: dict, page: Optional[Page]):
        name = task.get("tab", "")
        with BROWSER_LOCK:
            if name in self.state.pages:
                self.state.active_page = name
                active_page = self.state.pages[name]
                msg = f"Switched to {name}"
            else:
                active_page = self._get_active_page()
                msg = f"Tab {name} not found."

        return msg, take_screenshot(active_page)

    def handle_inspect(self, task: dict, page: Optional[Page]):
        if page is None:
            return "No active page.", None
        selector = task.get("selector", "")
        try:
            el = page.query_selector(selector)
            if not el:
                return f"No element found for selector: {selector}", take_screenshot(page)

            inner_text = el.inner_text()
            inner_html = el.inner_html()
            attrs = page.evaluate(
                """(el) => {
                    const out = {};
                    for (const a of el.attributes) out[a.name] = a.value;
                    return out;
                }""",
                el
            )
            xpath = page.evaluate(
                """(el) => {
                    function getXPath(node) {
                        if (node.id)
                            return 'id(\"' + node.id + '\")';
                        if (node === document.body)
                            return '/html/body';
                        let ix = 0;
                        const siblings = node.parentNode ? node.parentNode.childNodes : [];
                        for (let i=0; i<siblings.length; i++) {
                            const sibling = siblings[i];
                            if (sibling === node)
                                return getXPath(node.parentNode) + '/' + node.tagName.toLowerCase() + '[' + (ix+1) + ']';
                            if (sibling.nodeType === 1 && sibling.tagName === node.tagName)
                                ix++;
                        }
                    }
                    return getXPath(el);
                }""",
                el
            )

            info = (
                f"Selector: {selector}\n"
                f"XPath: {xpath}\n\n"
                f"Inner Text:\n{inner_text}\n\n"
                f"Attributes:\n{attrs}\n\n"
                f"Inner HTML (truncated):\n{inner_html[:1000]}"
            )
            return info, take_screenshot(page)
        except Exception as e:
            return f"Inspect error: {e}", take_screenshot(page)

    def handle_get_network_logs(self, task: dict, page: Optional[Page]):
        with BROWSER_LOCK:
            logs = list(self.state.network_logs)[-100:]
        text = "=== Network Logs (last 100) ===\n" + "\n".join(logs)
        return text, take_screenshot(page)

    def handle_get_console_logs(self, task: dict, page: Optional[Page]):
        with BROWSER_LOCK:
            logs = list(self.state.console_logs)[-100:]
        text = "=== Console Logs (last 100) ===\n" + "\n".join(logs)
        return text, take_screenshot(page)

    def handle_clear_logs(self, task: dict, page: Optional[Page]):
        with BROWSER_LOCK:
            self.state.network_logs.clear()
            self.state.console_logs.clear()
        return "Network & console logs cleared.", take_screenshot(page)

    def handle_start_record(self, task: dict, page: Optional[Page]):
        with BROWSER_LOCK:
            self.state.recording = True
            self.state.macro = []
        return "Macro recording started.", take_screenshot(page)

    def handle_stop_record(self, task: dict, page: Optional[Page]):
        with BROWSER_LOCK:
            self.state.recording = False
            steps = len(self.state.macro)
        return f"Macro recording stopped. {steps} steps recorded.", take_screenshot(page)

    def handle_play_macro(self, task: dict, page: Optional[Page]):
        with BROWSER_LOCK:
            macro_steps = list(self.state.macro)

        if not macro_steps:
            return "Macro is empty.", take_screenshot(self._get_active_page())

        last_result = ""
        current_page = self._get_active_page()

        for step in macro_steps:
            step_cmd = dict(step)
            step_cmd["from_macro"] = True
            cmd = step_cmd.get("cmd")

            if cmd == "goto":
                current_page = self._get_active_page()
                last_result, _ = self.handle_goto(step_cmd, current_page)
            elif cmd == "click":
                current_page = self._get_active_page()
                last_result, _ = self.handle_click(step_cmd, current_page)
            elif cmd == "type":
                current_page = self._get_active_page()
                last_result, _ = self.handle_type(step_cmd, current_page)
            elif cmd == "new_tab":
                last_result, _ = self.handle_new_tab(step_cmd, current_page)
                current_page = self._get_active_page()
            elif cmd == "close_tab":
                last_result, _ = self.handle_close_tab(step_cmd, current_page)
                current_page = self._get_active_page()
            elif cmd == "switch_tab":
                last_result, _ = self.handle_switch_tab(step_cmd, current_page)
                current_page = self._get_active_page()

        final_page = self._get_active_page()
        return f"Macro executed. {len(macro_steps)} steps.\nLast step: {last_result}", take_screenshot(final_page)

    def handle_take_screenshot(self, task: dict, page: Optional[Page]):
        if page is None:
            return "No active page.", None
        return "Screenshot captured.", take_screenshot(page)

    def handle_find_template(self, task: dict, page: Optional[Page]):
        template = task.get("template")
        if page is None:
            return "No active page.", None
        if template is None:
            return "Upload template first.", take_screenshot(page)

        img = take_screenshot(page)
        if img is None:
            return "Screenshot error.", None

        img_np = cv2.cvtColor(np.array(img), cv2.COLOR_RGB2GRAY)
        tpl_np = cv2.cvtColor(np.array(template), cv2.COLOR_RGB2GRAY)

        res = cv2.matchTemplate(img_np, tpl_np, cv2.TM_CCOEFF_NORMED)
        _, max_val, _, max_loc = cv2.minMaxLoc(res)

        if max_val < 0.55:
            return f"No strong match. Score={max_val:.2f}", img

        th, tw = tpl_np.shape

        draw = ImageDraw.Draw(img)
        draw.rectangle(
            [
                max_loc[0], max_loc[1],
                max_loc[0] + tw, max_loc[1] + th
            ],
            outline="yellow",
            width=3
        )

        return f"Match: score={max_val:.2f}", img


# ─────────────────────────────
# Worker spawn / shutdown helpers
# ─────────────────────────────

def start_worker_thread(storage_state:StorageState):
    worker = PlaywrightWorker(BROWSER_STATE,storage_state)
    t = threading.Thread(target=worker.run, daemon=True)
    t.start()
    with BROWSER_LOCK:
        BROWSER_STATE.thread = t
        BROWSER_STATE.running = True
        BROWSER_STATE.pages.clear()
        BROWSER_STATE.active_page = None
        BROWSER_STATE.network_logs.clear()
        BROWSER_STATE.console_logs.clear()
        BROWSER_STATE.macro.clear()
        BROWSER_STATE.recording = False
        BROWSER_STATE.tab_counter = 0


def stop_worker_thread():
    with BROWSER_LOCK:
        if not BROWSER_STATE.running:
            return
        BROWSER_STATE.running = False
        t = BROWSER_STATE.thread

    task_queue.put({"cmd": "__EXIT__"})
    if t is not None:
        t.join(timeout=5)