"""
SPDX-FileCopyrightText: © Sebastian Thomschke and contributors
SPDX-License-Identifier: AGPL-3.0-or-later
SPDX-ArtifactOfProjectHomePage: https://github.com/Second-Hand-Friends/kleinanzeigen-bot/
"""
import asyncio, enum, inspect, json, logging, os, platform, secrets, shutil, time
from collections.abc import Callable, Coroutine, Iterable
from typing import cast, Any, Final

try:
    from typing import Never  # type: ignore[attr-defined,unused-ignore] # mypy
except ImportError:
    from typing import NoReturn as Never  # Python <3.11

import nodriver, psutil
from nodriver.core.browser import Browser
from nodriver.core.config import Config
from nodriver.core.element import Element
from nodriver.core.tab import Tab as Page

from .utils import ensure, is_port_open, T


LOG:Final[logging.Logger] = logging.getLogger("kleinanzeigen_bot.selenium_mixin")


__all__ = [
    "Browser",
    "BrowserConfig",
    "By",
    "Element",
    "Page",
    "Is",
    "WebScrapingMixin"
]


class By(enum.Enum):
    ID = enum.auto()
    CLASS_NAME = enum.auto()
    CSS_SELECTOR = enum.auto()
    TAG_NAME = enum.auto()
    TEXT = enum.auto()
    XPATH = enum.auto()


class Is(enum.Enum):
    CLICKABLE = enum.auto()
    DISPLAYED = enum.auto()
    DISABLED = enum.auto()
    READONLY = enum.auto()
    SELECTED = enum.auto()


class BrowserConfig:

    def __init__(self) -> None:
        self.arguments:Iterable[str] = []
        self.binary_location:str | None = None
        self.extensions:Iterable[str] = []
        self.use_private_window:bool = True
        self.user_data_dir:str = ""
        self.profile_name:str = ""


class WebScrapingMixin:

    def __init__(self) -> None:
        self.browser_config:Final[BrowserConfig] = BrowserConfig()
        self.browser:Browser = None  # pyright: ignore
        self.page:Page = None  # pyright: ignore

    async def create_browser_session(self) -> None:
        LOG.info("Creating Browser session...")

        if self.browser_config.binary_location:
            ensure(os.path.exists(self.browser_config.binary_location), f"Specified browser binary [{self.browser_config.binary_location}] does not exist.")
        else:
            self.browser_config.binary_location = self.get_compatible_browser()
        LOG.info(" -> Chrome binary location: %s", self.browser_config.binary_location)

        ########################################################
        # check if an existing browser instance shall be used...
        ########################################################
        remote_host = "127.0.0.1"
        remote_port = 0
        for arg in self.browser_config.arguments:
            if arg.startswith("--remote-debugging-host="):
                remote_host = arg.split("=", 2)[1]
            if arg.startswith("--remote-debugging-port="):
                remote_port = int(arg.split("=", 2)[1])

        if remote_port > 0:
            LOG.info("Using existing browser process at %s:%s", remote_host, remote_port)
            if not is_port_open(remote_host, remote_port):
                raise AssertionError(f"Browser process not reachable at {remote_host}:{remote_port}. "
                        + f"Start the browser with --remote-debugging-port={remote_port} or remove this port from your config.yaml")
            cfg = Config(
                browser_executable_path = self.browser_config.binary_location  # actually not necessary but nodriver fails without
            )
            cfg.host = remote_host
            cfg.port = remote_port
            self.browser = await nodriver.start(cfg)
            LOG.info("New Browser session is %s", self.browser.websocket_url)
            return

        ########################################################
        # configure and initialize new browser instance...
        ########################################################

        # default_browser_args: @ https://github.com/ultrafunkamsterdam/nodriver/blob/main/nodriver/core/config.py
        # https://peter.sh/experiments/chromium-command-line-switches/
        # https://github.com/GoogleChrome/chrome-launcher/blob/main/docs/chrome-flags-for-tools.md
        browser_args = [
            # "--disable-dev-shm-usage", # https://stackoverflow.com/a/50725918/5116073
            "--disable-crash-reporter",
            "--disable-domain-reliability",
            "--disable-sync",
            "--no-experiments",

            "--disable-features=MediaRouter",
            "--use-mock-keychain",

            "--test-type",  # https://stackoverflow.com/a/36746675/5116073
            # https://chromium.googlesource.com/chromium/src/+/master/net/dns/README.md#request-remapping
            '--host-resolver-rules="MAP connect.facebook.net 127.0.0.1, MAP securepubads.g.doubleclick.net 127.0.0.1, MAP www.googletagmanager.com 127.0.0.1"'
        ]

        is_edge = "edge" in self.browser_config.binary_location.lower()

        if is_edge:
            os.environ["MSEDGEDRIVER_TELEMETRY_OPTOUT"] = "1"  # https://docs.microsoft.com/en-us/microsoft-edge/privacy-whitepaper/#microsoft-edge-driver

        if self.browser_config.use_private_window:
            browser_args.append("-inprivate" if is_edge else "--incognito")

        if self.browser_config.profile_name:
            LOG.info(" -> Browser profile name: %s", self.browser_config.profile_name)
            browser_args.append(f"--profile-directory={self.browser_config.profile_name}")

        for browser_arg in self.browser_config.arguments:
            LOG.info(" -> Custom Chrome argument: %s", browser_arg)
            browser_args.append(browser_arg)

        if not LOG.isEnabledFor(logging.DEBUG):
            browser_args.append("--log-level=3")  # INFO: 0, WARNING: 1, ERROR: 2, FATAL: 3

        if self.browser_config.user_data_dir:
            LOG.info(" -> Browser user data dir: %s", self.browser_config.user_data_dir)

        cfg = Config(
            headless = False,
            browser_executable_path = self.browser_config.binary_location,
            browser_args = browser_args,
            user_data_dir = self.browser_config.user_data_dir
        )

        # already logged by nodriver:
        # LOG.debug("-> Effective browser arguments: \n\t\t%s", "\n\t\t".join(cfg.browser_args))

        profile_dir = os.path.join(cfg.user_data_dir, self.browser_config.profile_name or "Default")
        os.makedirs(profile_dir, exist_ok = True)
        prefs_file = os.path.join(profile_dir, "Preferences")
        if not os.path.exists(prefs_file):
            LOG.info("-> Setting chrome prefs [%s]...", prefs_file)
            with open(prefs_file, "w", encoding='UTF-8') as fd:
                json.dump({
                    "credentials_enable_service": False,
                    "enable_do_not_track": True,
                    "google": {
                        "services": {
                            "consented_to_sync": False
                        }
                    },
                    "profile": {
                        "default_content_setting_values": {
                            "popups": 0,
                            "notifications": 2  # 1 = allow, 2 = block browser notifications
                        },
                        "password_manager_enabled": False
                    },
                    "signin": {
                        "allowed": False
                    },
                    "translate_site_blacklist": [
                        "www.kleinanzeigen.de"
                    ],
                    "devtools": {
                        "preferences": {
                            "currentDockState": '"bottom"'
                        }
                    }
                }, fd)

        # load extensions
        for crx_extension in self.browser_config.extensions:
            LOG.info(" -> Adding extension: [%s]", crx_extension)
            ensure(os.path.exists(crx_extension), f"Configured extension-file [{crx_extension}] does not exist.")
            cfg.add_extension(crx_extension)

        self.browser = await nodriver.start(cfg)
        LOG.info("New Browser session is %s", self.browser.websocket_url)

    def close_browser_session(self) -> None:
        if self.browser:
            LOG.debug("Closing Browser session...")
            self.page = None  # pyright: ignore
            browser_process = psutil.Process(self.browser._process_pid)  # pylint: disable=protected-access
            browser_children:list[psutil.Process] = browser_process.children()
            self.browser.stop()
            for p in browser_children:
                if p.is_running():
                    p.kill()  # terminate orphaned browser processes
            self.browser = None  # pyright: ignore

    def get_compatible_browser(self) -> str:
        match platform.system():
            case "Linux":
                browser_paths = [
                    shutil.which("chromium"),
                    shutil.which("chromium-browser"),
                    shutil.which("google-chrome"),
                    shutil.which("microsoft-edge")
                ]

            case "Darwin":
                browser_paths = [
                    "/Applications/Chromium.app/Contents/MacOS/Chromium",
                    "/Applications/Google Chrome.app/Contents/MacOS/Google Chrome",
                    "/Applications/Microsoft Edge.app/Contents/MacOS/Microsoft Edge",
                ]

            case "Windows":
                browser_paths = [
                    os.environ.get("ProgramFiles", "C:\\Program Files") + r'\Microsoft\Edge\Application\msedge.exe',
                    os.environ.get("ProgramFiles(x86)", "C:\\Program Files (x86)") + r'\Microsoft\Edge\Application\msedge.exe',

                    os.environ["ProgramFiles"] + r'\Chromium\Application\chrome.exe',
                    os.environ["ProgramFiles(x86)"] + r'\Chromium\Application\chrome.exe',
                    os.environ["LOCALAPPDATA"] + r'\Chromium\Application\chrome.exe',

                    os.environ["ProgramFiles"] + r'\Chrome\Application\chrome.exe',
                    os.environ["ProgramFiles(x86)"] + r'\Chrome\Application\chrome.exe',
                    os.environ["LOCALAPPDATA"] + r'\Chrome\Application\chrome.exe',

                    shutil.which("msedge.exe"),
                    shutil.which("chromium.exe"),
                    shutil.which("chrome.exe")
                ]

            case _ as os_name:
                raise AssertionError(f"Installed browser for OS [{os_name}] could not be detected")

        for browser_path in browser_paths:
            if browser_path and os.path.isfile(browser_path):
                return browser_path

        raise AssertionError("Installed browser could not be detected")

    async def web_await(self, condition: Callable[[], T | Never | Coroutine[Any,Any,T | Never]], *,
            timeout:int | float = 5, timeout_error_message: str = "") -> T:
        """
        Blocks/waits until the given condition is met.

        :param timeout: timeout in seconds
        :raises TimeoutError: if element could not be found within time
        """
        loop = asyncio.get_running_loop()
        start_at = loop.time()

        while True:
            await self.page
            ex:Exception | None = None
            try:
                result_raw = condition()
                result:T = (await result_raw) if inspect.isawaitable(result_raw) else result_raw
                if result:
                    return result
            except Exception as ex1:
                ex = ex1
            if loop.time() - start_at > timeout:
                if ex:
                    raise ex
                raise TimeoutError(timeout_error_message or f"Condition not met within {timeout} seconds")
            await self.page.sleep(0.5)

    async def web_check(self, selector_type:By, selector_value:str, attr:Is, *, timeout:int | float = 5) -> bool:
        """
        Locates an HTML element and returns a state.

        :param timeout: timeout in seconds
        :raises TimeoutError: if element could not be found within time
        """

        def is_disabled(elem:Element) -> bool:
            return elem.attrs.get("disabled") is not None

        async def is_displayed(elem:Element) -> bool:
            return cast(bool, await elem.apply("""
                function (element) {
                    var style = window.getComputedStyle(element);
                    return style.display !== 'none'
                        && style.visibility !== 'hidden'
                        && style.opacity !== '0'
                        && element.offsetWidth > 0
                        && element.offsetHeight > 0
                }
            """))
        elem:Element = await self.web_find(selector_type, selector_value, timeout = timeout)

        match attr:
            case Is.CLICKABLE:
                return not is_disabled(elem) or await is_displayed(elem)
            case Is.DISPLAYED:
                return await is_displayed(elem)
            case Is.DISABLED:
                return is_disabled(elem)
            case Is.READONLY:
                return elem.attrs.get("readonly") is not None
            case Is.SELECTED:
                return cast(bool, await elem.apply("""
                    function (element) {
                        if (element.tagName.toLowerCase() === 'input') {
                            if (element.type === 'checkbox' || element.type === 'radio') {
                                return element.checked
                            }
                        }
                        return false
                    }
                """))
        raise AssertionError(f"Unsupported attribute: {attr}")

    async def web_click(self, selector_type:By, selector_value:str, *, timeout:int | float = 5) -> Element:
        """
        Locates an HTML element by ID.

        :param timeout: timeout in seconds
        :raises TimeoutError: if element could not be found within time
        """
        elem = await self.web_find(selector_type, selector_value, timeout = timeout)
        await elem.click()
        await self.web_sleep()
        return elem

    async def web_execute(self, javascript:str) -> Any:
        """
        Executes the given JavaScript code in the context of the current page.

        :return: The javascript's return value
        """
        return await self.page.evaluate(javascript, True)

    async def web_find(self, selector_type:By, selector_value:str, *, parent:Element = None, timeout:int | float = 5) -> Element:
        """
        Locates an HTML element by the given selector type and value.

        :param timeout: timeout in seconds
        :raises TimeoutError: if element could not be found within time
        """
        match selector_type:
            case By.ID:
                return await self.web_await(
                    lambda: self.page.query_selector(f"#{selector_value}", parent),
                    timeout = timeout,
                    timeout_error_message = f"No HTML element found with ID '{selector_value}' within {timeout} seconds.")
            case By.CLASS_NAME:
                return await self.web_await(
                    lambda: self.page.query_selector(f".{selector_value}", parent),
                    timeout = timeout,
                    timeout_error_message = f"No HTML element found with ID '{selector_value}' within {timeout} seconds.")
            case By.TAG_NAME:
                return await self.web_await(
                    lambda: self.page.query_selector(selector_value, parent),
                    timeout = timeout,
                    timeout_error_message = f"No HTML element found of tag <{selector_value}> within {timeout} seconds.")
            case By.CSS_SELECTOR:
                return await self.web_await(
                    lambda: self.page.query_selector(selector_value, parent),
                    timeout = timeout,
                    timeout_error_message = f"No HTML element found using CSS selector '{selector_value}' within {timeout} seconds.")
            case By.TEXT:
                if parent:
                    raise AssertionError(f"Specifying a parent element currently not supported with selector type: {selector_type}")
                return await self.web_await(
                    lambda: self.page.find_element_by_text(selector_value, True),
                    timeout = timeout,
                    timeout_error_message = f"No HTML element found containing text '{selector_value}' within {timeout} seconds.")
            case By.XPATH:
                if parent:
                    raise AssertionError(f"Specifying a parent element currently not supported with selector type: {selector_type}")
                return await self.web_await(
                    lambda: self.page.find_element_by_text(selector_value, True),
                    timeout = timeout,
                    timeout_error_message = f"No HTML element found using XPath '{selector_value}' within {timeout} seconds.")

        raise AssertionError(f"Unsupported selector type: {selector_type}")

    async def web_find_all(self, selector_type:By, selector_value:str, *, parent:Element = None, timeout:int | float = 5) -> list[Element]:
        """
        Locates an HTML element by ID.

        :param timeout: timeout in seconds
        :raises TimeoutError: if element could not be found within time
        """
        match selector_type:
            case By.CLASS_NAME:
                return await self.web_await(
                    lambda: self.page.query_selector_all(f".{selector_value}", parent),
                    timeout = timeout,
                    timeout_error_message = f"No HTML elements found with CSS class '{selector_value}' within {timeout} seconds.")
            case By.CSS_SELECTOR:
                return await self.web_await(
                    lambda: self.page.query_selector_all(selector_value, parent),
                    timeout = timeout,
                    timeout_error_message = f"No HTML elements found using CSS selector '{selector_value}' within {timeout} seconds.")
            case By.TAG_NAME:
                return await self.web_await(
                    lambda: self.page.query_selector_all(selector_value, parent),
                    timeout = timeout,
                    timeout_error_message = f"No HTML elements found of tag <{selector_value}> within {timeout} seconds.")
            case By.TEXT:
                if parent:
                    raise AssertionError(f"Specifying a parent element currently not supported with selector type: {selector_type}")
                return await self.web_await(
                    lambda: self.page.find_elements_by_text(selector_value),
                    timeout = timeout,
                    timeout_error_message = f"No HTML elements found containing text '{selector_value}' within {timeout} seconds.")
            case By.XPATH:
                if parent:
                    raise AssertionError(f"Specifying a parent element currently not supported with selector type: {selector_type}")
                return await self.web_await(
                    lambda: self.page.find_elements_by_text(selector_value),
                    timeout = timeout,
                    timeout_error_message = f"No HTML elements found using XPath '{selector_value}' within {timeout} seconds.")

        raise AssertionError(f"Unsupported selector type: {selector_type}")

    async def web_input(self, selector_type:By, selector_value:str, text:str | int, *, timeout:int | float = 5) -> Element:
        """
        Enters text into an HTML input field.

        :param timeout: timeout in seconds
        :raises TimeoutError: if element could not be found within time
        """
        input_field = await self.web_find(selector_type, selector_value, timeout = timeout)
        await input_field.clear_input()
        await input_field.send_keys(str(text))
        await self.web_sleep()
        return input_field

    async def web_open(self, url:str, *, timeout:int | float = 15000, reload_if_already_open:bool = False) -> None:
        """
        :param url: url to open in browser
        :param timeout: timespan in seconds within the page needs to be loaded
        :param reload_if_already_open: if False does nothing if the URL is already open in the browser
        :raises TimeoutException: if page did not open within given timespan
        """
        LOG.debug(" -> Opening [%s]...", url)
        if not reload_if_already_open and self.page and url == self.page.url:
            LOG.debug("  => skipping, [%s] is already open", url)
            return
        self.page = await self.browser.get(url, False, False)
        await self.web_await(lambda: self.web_execute("document.readyState == 'complete'"), timeout = timeout,
                timeout_error_message = f"Page did not finish loading within {timeout} seconds.")

    async def web_text(self, selector_type:By, selector_value:str, *, parent:Element = None, timeout:int | float = 5) -> str:
        return str(await (await self.web_find(selector_type, selector_value, parent = parent, timeout = timeout)).apply("""
            function (elem) {
                let sel = window.getSelection()
                sel.removeAllRanges()
                let range = document.createRange()
                range.selectNode(elem)
                sel.addRange(range)
                let visibleText = sel.toString().trim()
                sel.removeAllRanges()
                return visibleText
            }
        """))

    async def web_sleep(self, min_ms:int = 1000, max_ms:int = 2500) -> None:
        duration = max_ms <= min_ms and min_ms or secrets.randbelow(max_ms - min_ms) + min_ms
        LOG.log(logging.INFO if duration > 1500 else logging.DEBUG, " ... pausing for %d ms ...", duration)
        await self.page.sleep(duration / 1000)

    async def web_request(self, url:str, method:str = "GET", valid_response_codes:int | Iterable[int] = 200,
            headers:dict[str, str] | None = None) -> dict[str, Any]:
        method = method.upper()
        LOG.debug(" -> HTTP %s [%s]...", method, url)
        response = cast(dict[str, Any], await self.page.evaluate(f"""
            fetch("{url}", {{
                method: "{method}",
                redirect: "follow",
                headers: {headers or {}}
            }})
            .then(response => response.text().then(responseText => {{
                headers = {{}};
                response.headers.forEach((v, k) => headers[k] = v);
                return {{
                    statusCode: response.status,
                    statusMessage: response.statusText,
                    headers: headers,
                    content: responseText
                }}
            }}))
        """, await_promise=True))
        if isinstance(valid_response_codes, int):
            valid_response_codes = [valid_response_codes]
        ensure(
            response["statusCode"] in valid_response_codes,
            f'Invalid response "{response["statusCode"]} response["statusMessage"]" received for HTTP {method} to {url}'
        )
        return response
    # pylint: enable=dangerous-default-value

    async def web_scroll_page_down(self, scroll_length: int = 10, scroll_speed: int = 10000, scroll_back_top: bool = False) -> None:
        """
        Smoothly scrolls the current web page down.

        :param scroll_length: the length of a single scroll iteration, determines smoothness of scrolling, lower is smoother
        :param scroll_speed: the speed of scrolling, higher is faster
        :param scroll_back_top: whether to scroll the page back to the top after scrolling to the bottom
        """
        current_y_pos = 0
        bottom_y_pos: int = await self.web_execute('document.body.scrollHeight')  # get bottom position
        while current_y_pos < bottom_y_pos:  # scroll in steps until bottom reached
            current_y_pos += scroll_length
            await self.web_execute(f'window.scrollTo(0, {current_y_pos})')  # scroll one step
            time.sleep(scroll_length / scroll_speed)

        if scroll_back_top:  # scroll back to top in same style
            while current_y_pos > 0:
                current_y_pos -= scroll_length
                await self.web_execute(f'window.scrollTo(0, {current_y_pos})')
                time.sleep(scroll_length / scroll_speed / 2)  # double speed

    async def web_select(self, selector_type:By, selector_value:str, selected_value:Any, timeout:int | float = 5) -> Element:
        """
        Selects an <option/> of a <select/> HTML element.

        :param timeout: timeout in seconds
        :raises TimeoutError: if element could not be found within time
        :raises UnexpectedTagNameException: if element is not a <select> element
        """
        await self.web_await(
            lambda: self.web_check(selector_type, selector_value, Is.CLICKABLE), timeout = timeout,
            timeout_error_message = f"No clickable HTML element with selector: {selector_type}='{selector_value}' found"
        )
        elem = await self.web_find(selector_type, selector_value)
        await elem.apply(f"""
            function (element) {{
              for(let i=0; i < element.options.length; i++)
                {{
                  if(element.options[i].value == "{selected_value}") {{
                    element.selectedIndex = i;
                    element.dispatchEvent(new Event('change', {{ bubbles: true }}));
                    break;
                }}
              }}
              throw new Error("Option with value {selected_value} not found.");
            }}
        """)
        await self.web_sleep()
        return elem