import json
import re

from bridge import AsyncBridge as Bridge
from browser import DOMNode, aio, console as log, document, window
from cache import cache, identities
import dialog
from file_uploader import FileUploader
import jid
from js_modules import emoji_picker_element
from js_modules.tippy_js import tippy
import popup
from template import Template, safe
from tools import is_touch_device

log.warning = log.warn
profile = window.profile or ""
own_jid = jid.JID(window.own_jid)
target_jid = jid.JID(window.target_jid)
chat_type = window.chat_type
bridge = Bridge()

# Sensible value to consider that user is at the bottom
SCROLL_SENSITIVITY = 200

INPUT_MODES = {"normal", "edit", "quote"}
MODE_CLASS = "mode_{}"


class LiberviaWebChat:
    def __init__(self):
        self._input_mode = "normal"
        self.input_data = {}
        self.message_tpl = Template("chat/message.html")
        self.extra_menu_tpl = Template("chat/extra_menu.html")
        self.reactions_tpl = Template("chat/reactions.html")
        self.reactions_details_tpl = Template("chat/reactions_details.html")
        self.url_preview_control_tpl = Template("components/url_preview_control.html")
        self.url_preview_tpl = Template("components/url_preview.html")
        self.new_messages_marker_elt = Template("chat/new_messages_marker.html").get_elt()
        self.editions_tpl = Template("chat/editions.html")

        self.messages_elt = document["messages"]

        # attachments
        self.file_uploader = FileUploader(
            "", "chat/attachment_preview.html", on_delete_cb=self.on_attachment_delete
        )
        self.attachments_elt = document["attachments"]
        self.message_input = document["message_input"]

        close_button = document.select_one(".modal-close")
        close_button.bind("click", self.close_modal)

        # hide/show attachments
        MutationObserver = window.MutationObserver
        observer = MutationObserver.new(lambda *__: self.update_attachments_visibility())
        observer.observe(self.attachments_elt, {"childList": True})

        # we want the message scroll to be initially at the bottom
        self.messages_elt.scrollTop = self.messages_elt.scrollHeight

        # listeners/dynamic updates
        self.add_message_event_listeners()
        self.handle_url_previews()
        self.add_reactions_listeners()

        # input
        self.auto_resize_message_input()
        self.message_input.focus()

    @property
    def input_mode(self) -> str:
        return self._input_mode

    @input_mode.setter
    def input_mode(self, new_mode: str) -> None:
        if new_mode == self.input_mode:
            return
        if new_mode not in INPUT_MODES:
            raise ValueError(f"Invalid input mode: {new_mode!r}")
        target_elt = self.message_input
        target_elt.classList.remove(MODE_CLASS.format(self._input_mode))
        self._input_mode = new_mode
        target_elt.classList.add(MODE_CLASS.format(new_mode))
        self.input_data.clear()

    @property
    def is_at_bottom(self):
        return (
            self.messages_elt.scrollHeight
            - self.messages_elt.scrollTop
            - self.messages_elt.clientHeight
            <= SCROLL_SENSITIVITY
        )

    async def send_message(self):
        """Send message currently in input area

        The message and corresponding attachment will be sent
        """
        message = self.message_input.value.rstrip()
        log.info(f"{message=}")

        # attachments
        attachments = []
        for attachment_elt in self.attachments_elt.children:
            file_data = json.loads(attachment_elt.getAttribute("data-file"))
            attachments.append(file_data)

        if message or attachments:
            extra = {}

            if attachments:
                extra["attachments"] = attachments

            # now we send the message
            try:
                if self.input_mode == "edit":
                    message_id = self.input_data["id"]
                    edit_data = {
                        "message": {"": message},
                        "extra": extra
                    }
                    await bridge.message_edit(
                            message_id, json.dumps(edit_data, ensure_ascii=False)
                        )
                else:
                    await bridge.message_send(
                        str(target_jid),
                        {"": message}, {}, "auto", json.dumps(extra, ensure_ascii=False)
                    )
            except Exception as e:
                dialog.notification.show(f"Can't send message: {e}", "error")
            else:
                self.message_input.value = ""
                self.attachments_elt.clear()
        self.input_mode = "normal"

    def _on_message_new(
        self,
        uid: str,
        timestamp: float,
        from_jid_s: str,
        to_jid_s: str,
        message: dict,
        subject: dict,
        mess_type: str,
        extra_s: str,
        profile: str,
    ) -> None:
        from_jid = jid.JID(from_jid_s)
        to_jid = jid.JID(to_jid_s)
        if (
            from_jid.bare == window.target_jid
            or to_jid.bare == window.target_jid
        ):
            aio.run(
                self.on_message_new(
                    uid,
                    timestamp,
                    from_jid,
                    to_jid,
                    message,
                    subject,
                    mess_type,
                    json.loads(extra_s),
                    profile,
                )
            )

    def _on_message_update(
        self, uid: str, type_: str, update_data_s: str, profile: str
    ) -> None:
        aio.run(self.on_message_update(uid, type_, update_data_s, profile))

    async def on_message_update(
        self, uid: str, type_: str, update_data_s: str, profile: str
    ) -> None:
        update_data = json.loads(update_data_s)
        is_at_bottom = self.is_at_bottom
        if type_ == "REACTION":
            reactions = update_data["reactions"]
            log.debug(f"new reactions: {reactions}")
            try:
                reactions_wrapper_elt = document[f"msg_reactions_{uid}"]
            except KeyError:
                log.debug(f"Message {uid} not found, no reactions to update")
            else:
                log.debug(f"Message {uid} found, new reactions: {reactions}")
                reactions_elt = self.reactions_tpl.get_elt({"reactions": reactions})
                reactions_wrapper_elt.clear()
                reactions_wrapper_elt <= reactions_elt
                self.add_reactions_listeners(reactions_elt)
        elif type_ in ("EDIT", "RETRACT"):
            try:
                old_message_elt = document[uid]
            except KeyError:
                log.debug(f"Message {uid} not found, no {type_.lower()}ion to apply")
            else:
                template_data = await self.message_to_template_data(
                    uid,
                    update_data["timestamp"],
                    jid.JID(update_data["from"]),
                    jid.JID(update_data["to"]),
                    update_data["message"],
                    update_data["subject"],
                    update_data["type"],
                    update_data["extra"]
                )

                new_message_elt = self.message_tpl.get_elt(
                    template_data
                )
                old_message_elt.replaceWith(new_message_elt)
                self.add_message_event_listeners(new_message_elt)
                self.handle_url_previews(new_message_elt)
        else:
            log.warning(f"Unsupported update type: {type_!r}")

        # If user was at the bottom, keep the scroll at the bottom
        if is_at_bottom:
            self.messages_elt.scrollTop = self.messages_elt.scrollHeight

    async def message_to_template_data(
        self,
        uid: str,
        timestamp: float,
        from_jid: jid.JID,
        to_jid: jid.JID,
        message_data: dict,
        subject_data: dict,
        mess_type: str,
        extra: dict,
    ) -> dict:
        """Generate template data to use with [message_tpl]

            @return: template data
        """
        xhtml_data = extra.get("xhtml")
        if not xhtml_data:
            xhtml = None
        else:
            try:
                xhtml = xhtml_data[""]
            except KeyError:
                xhtml = next(iter(xhtml_data.values()))

        if chat_type == "group":
            await cache.fill_identities([str(from_jid)])
        else:
            await cache.fill_identities([str(jid.JID(from_jid).bare)])
            from_jid = from_jid.bare

        return {
            "own_jid": own_jid,
            "msg": {
                "id": uid,
                "timestamp": extra.get("updated", timestamp),
                "type": mess_type,
                "from_": str(from_jid),
                "text": message_data.get("") or next(iter(message_data.values()), ""),
                "subject": subject_data.get("") or next(iter(subject_data.values()), ""),
                "type": mess_type,
                "thread": extra.get("thread"),
                "thread_parent": extra.get("thread_parent"),
                "reeceived": extra.get("received_timestamp") or timestamp,
                "delay_sender": extra.get("delay_sender"),
                "info_type": extra.get("info_type"),
                "html": safe(xhtml) if xhtml else None,
                "encrypted": extra.get("encrypted", False),
                "received": extra.get("received", False),
                "attachments": extra.get("attachments", []),
                "extra": extra
            },
            "identities": identities,
        }

    async def on_message_new(
        self,
        uid: str,
        timestamp: float,
        from_jid: jid.JID,
        to_jid: jid.JID,
        message_data: dict,
        subject_data: dict,
        mess_type: str,
        extra: dict,
        profile: str,
    ) -> None:
        # FIXME: visibilityState doesn't detect OS events such as `Alt + Tab`, using focus
        #   event may help to get those use cases, but it gives false positives.
        if (
            document.visibilityState == "hidden"
            and self.new_messages_marker_elt.parent is None
        ):
            # the page is not visible, and we have no new messages marker yet, so we add
            # it
            self.messages_elt <= self.new_messages_marker_elt

        template_data = await self.message_to_template_data(
            uid,
            timestamp,
            from_jid,
            to_jid,
            message_data,
            subject_data,
            mess_type,
            extra
        )

        message_elt = self.message_tpl.get_elt(
            template_data
        )

        # Check if user is viewing older messages or is at the bottom
        is_at_bottom = self.is_at_bottom

        self.messages_elt <= message_elt
        self.add_message_event_listeners(message_elt)
        # we add preview in parallel on purpose, as they can be slow to get
        self.handle_url_previews(message_elt)

        # If user was at the bottom, keep the scroll at the bottom
        if is_at_bottom:
            self.messages_elt.scrollTop = self.messages_elt.scrollHeight

    def auto_resize_message_input(self):
        """Resize the message input field according to content."""

        is_at_bottom = self.is_at_bottom

        # The textarea's height is first reset to 'auto' to ensure it's not influenced by
        # the previous content.
        self.message_input.style.height = "auto"

        # Then the height is set to the scrollHeight of the textarea (which is the height
        # of the content), plus the vertical border, resulting in a textarea that grows as
        # more lines of text are added.
        self.message_input.style.height = f"{self.message_input.scrollHeight + 2}px"

        if is_at_bottom:
            # we want the message are to still display the last message
            self.messages_elt.scrollTop = self.messages_elt.scrollHeight

    def on_message_keydown(self, evt):
        """Handle the 'keydown' event of the message input field

        @param evt: The event object. 'target' refers to the textarea element.
        """
        if evt.keyCode == 13:  # <Enter> key
            if not window.navigator.maxTouchPoints:
                # we have a non touch device, we send message on <Enter>
                if not evt.shiftKey:
                    evt.preventDefault()  # Prevents line break
                    aio.run(self.send_message())
        elif evt.keyCode == 27:  # <ESC> key
            evt.preventDefault()
            self.message_input.value = ''
            self.input_mode = 'normal'
            self.auto_resize_message_input()
        elif evt.keyCode == 38:  # <Up> arrow key
            if self.input_mode == "normal" and self.message_input.value.strip() == "":
                evt.preventDefault()
                own_msgs = document.getElementsByClassName('own_msg')
                if own_msgs.length > 0:
                    last_msg = own_msgs[own_msgs.length - 1]
                    aio.run(self.on_action_edit(None, last_msg))

    def update_attachments_visibility(self):
        if len(self.attachments_elt.children):
            self.attachments_elt.classList.remove("is-contracted")
        else:
            self.attachments_elt.classList.add("is-contracted")

    def on_file_selected(self, evt):
        """Handle file selection"""
        log.info("file selected")
        files = evt.currentTarget.files
        self.file_uploader.upload_files(files, self.attachments_elt)
        self.message_input.focus()

    def on_attachment_delete(self, evt):
        evt.stopPropagation()
        target = evt.currentTarget
        item_elt = DOMNode(target.closest(".attachment-preview"))
        item_elt.remove()

    def on_attach_button_click(self, evt):
        document["file_input"].click()

    def on_extra_btn_click(self, evt):
        message_elt = evt.target.closest("div.is-chat-message")
        is_own = message_elt.classList.contains("own_msg")
        if is_own:
            own_messages = document.select('.own_msg')
            # with XMPP, we can currently only edit our last message
            can_edit = own_messages and message_elt is own_messages[-1]
        else:
            can_edit = False

        content_elt = self.extra_menu_tpl.get_elt({
            "edit": can_edit,
            "retract": is_own,
        })
        extra_popup = popup.create_popup(evt.target, content_elt, focus_elt=message_elt)

        def on_action_click(evt, callback):
            extra_popup.hide()
            aio.run(
                callback(evt, message_elt)
            )

        for cls_name, callback in (
            ("action_quote", self.on_action_quote),
            ("action_edit", self.on_action_edit),
            ("action_retract", self.on_action_retract),
        ):
            for elt in content_elt.select(f".{cls_name}"):
                elt.bind("click", lambda evt, callback=callback: on_action_click(
                    evt, callback
                ))

    def on_reaction_click(self, evt, message_elt):
        window.evt = evt
        aio.run(
            bridge.message_reactions_set(
                message_elt["id"], [evt.detail["unicode"]], "toggle"
            )
        )
        if evt.deltaY != 0:
            document["attachments"].scrollLeft += evt.deltaY * 0.8
            evt.preventDefault()

    async def get_message_tuple(self, message_elt) -> tuple|None:
        """Retrieve message tuple from as sent by [message_new]

        If not corresponding message data is found, an error will shown, and None is
        returned.
        @param message_elt: message element, it's "id" attribute will be use to retrieve
            message data
        @return: message data as a tuple, or None if not message with this ID is found.
        """
        message_id = message_elt['id']
        history_data = await bridge.history_get(
            "", "", -2, True, {"id": message_elt['id']}
        )
        if not history_data:
            dialog.notification.show(f"Can't find message {message_id}", "error")
            return None
        return history_data[0]

    async def on_action_quote(self, __, message_elt) -> None:
        message_data = await self.get_message_tuple(message_elt)
        if message_data is not None:
            messages = message_data[4]
            body = next(iter(messages.values()), "")
            quote = "\n".join(f"> {l}" for l in body.split("\n"))
            self.message_input.value = f"{quote}\n{self.message_input.value}"
            self.input_mode = "quote"
            self.input_data["id"] = message_elt["id"]
            self.auto_resize_message_input()
            self.message_input.focus()

    async def on_action_edit(self, __, message_elt) -> None:
        message_data = await self.get_message_tuple(message_elt)
        if message_data is not None:
            messages = message_data[4]
            body = next(iter(messages.values()), "")
            if not body:
                dialog.notification.show("No content found in message, nothing to edit")
                return

            self.message_input.value = body
            self.input_mode = "edit"
            self.input_data["id"] = message_elt["id"]
            self.auto_resize_message_input()
            self.message_input.focus()

    async def on_action_retract(self, __, message_elt) -> None:
        confirmed = await dialog.Confirm(safe(
            "This message will be permanently removed. Are you sure?<br><br>"
            "WARNING: It is impossible to guarantee that other participants in the "
            "discussion will delete this message as well. You must assume it has been "
            "seen. If a password or other sensitive information has been accidentally "
            "shared, please ensure to take appropriate measures to change it and "
            "mitigate the risks."
        )).ashow()
        if confirmed:
            await bridge.message_retract(message_elt["id"])
        else:
            log.info(f"Retraction of message {message_elt['id']} cancelled by user.")

    def get_reaction_panel(self, source_elt):
        emoji_picker_elt = document.createElement("emoji-picker")
        message_elt = source_elt.closest("div.is-chat-message")
        emoji_picker_elt.bind(
            "emoji-click", lambda evt: self.on_reaction_click(evt, message_elt)
        )

        return emoji_picker_elt

    def add_message_event_listeners(self, parent_elt=None):
        """Prepare a message to be dynamic

        - make attachments dynamically clickable
        - make the extra button clickable
        """
        ## attachments
        # FIXME: only handle images for now, and display them in a modal
        if parent_elt is None:
            parent_elt = document
        img_elts = parent_elt.select(".message-attachment img")
        for img_elt in img_elts:
            img_elt.bind("click", self.open_modal)
            img_elt.style.cursor = "pointer"

        ## reaction button
        for reaction_btn in parent_elt.select(".reaction-button"):
            message_elt = reaction_btn.closest("div.is-chat-message")
            tippy(
                reaction_btn,
                {
                    "trigger": "click",
                    "content": self.get_reaction_panel,
                    "appendTo": document.body,
                    "placement": "bottom",
                    "interactive": True,
                    "theme": "light",
                    "onShow": lambda __, message_elt=message_elt: (
                        message_elt.classList.add("has-popup-focus")
                    ),
                    "onHide": lambda __, message_elt=message_elt: (
                        message_elt.classList.remove("has-popup-focus")
                    ),
                },
            )

        ## extra button
        for extra_btn in parent_elt.select(".extra-button"):
            extra_btn.bind("click", self.on_extra_btn_click)

        ## editions
        for edition_icon_elt in parent_elt.select(".message-editions"):
            message_elt = edition_icon_elt.closest("div.is-chat-message")
            dataset = message_elt.dataset.to_dict()
            try:
                editions = json.loads(dataset["editions"])
            except (ValueError, KeyError):
                log.error(
                    f"Internal Error: invalid or missing editions data: {message_elt['id']}"
                )
            else:
                for edition in editions:
                    edition["text"] = (
                        edition["message"].get("")
                        or next(iter(edition["message"].values()), "")
                    )
                editions_elt = self.editions_tpl.get_elt({"editions": editions})
                tippy(
                    edition_icon_elt,
                    {
                        "content": editions_elt,
                        "theme": "light",
                        "appendTo": document.body
                    }

                )

    def add_reactions_listeners(self, parent_elt=None) -> None:
        """Add listener on reactions to handle details and reaction toggle"""
        if parent_elt is None:
            parent_elt = document

        is_touch = is_touch_device()

        for reaction_elt in parent_elt.select(".reaction"):
            # Reaction details
            dataset = reaction_elt.dataset.to_dict()
            reacting_jids = sorted(json.loads(dataset.get("jids", "[]")))
            reaction_details_elt = self.reactions_details_tpl.get_elt(
                {"reacting_jids": reacting_jids, "identities": identities}
            )

            # Configure tippy based on device type
            tippy_config = {
                "content": reaction_details_elt,
                "placement": "bottom",
                "theme": "light",
                "touch": ["hold", 500] if is_touch else True,
                "trigger": "click" if is_touch else "mouseenter focus",
                "delay": [0, 800] if is_touch else 0,
            }
            tippy(reaction_elt, tippy_config)

            # Toggle reaction when clicked/touched
            emoji_elt = reaction_elt.select_one(".emoji")
            emoji = emoji_elt.html.strip()
            message_elt = reaction_elt.closest("div.is-chat-message")
            msg_id = message_elt["id"]

            def toggle_reaction(event, msg_id=msg_id, emoji=emoji):
                # Prevent default if it's a touch device to distinguish from long press
                if is_touch:
                    event.preventDefault()
                aio.run(bridge.message_reactions_set(msg_id, [emoji], "toggle"))

            reaction_elt.bind("click", toggle_reaction)

    def find_links(self, message_elt):
        """Find all http and https links within the body of a message."""
        msg_body_elt = message_elt.select_one(".msg_body")
        if not msg_body_elt:
            return

        # Extracting links from text content
        text = msg_body_elt.text
        raw_urls = re.findall(
            r"http[s]?://(?:[a-zA-Z]|[0-9]|[$-_@.&+]|[!*\\(\\),]|(?:%[0-9a-fA-F][0-9a-fA-F])|#)+",
            text,
        )

        # Extracting links from <a> elements
        a_elements = msg_body_elt.select("a")
        for a_elt in a_elements:
            href = a_elt.attrs.get("href", "")
            if href.startswith("http://") or href.startswith("https://"):
                raw_urls.append(href)

        # we remove duplicates
        urls = list(dict.fromkeys(raw_urls))

        return urls

    async def add_url_previews(self, url_previews_elt, urls) -> None:
        """Add URL previews to the .url-previews element of a message."""
        url_previews_elt.clear()
        for url in urls:
            try:
                url_preview_data_s = await bridge.url_preview_get(url, "")
            except Exception as e:
                log.warning(f"Couldn't get URL preview for {url}: {e}")
                continue

            if not url_preview_data_s:
                log.warning(f"No preview could be found for URL: {url}")
                continue

            url_preview_data = json.loads(url_preview_data_s)

            url_preview_elt = self.url_preview_tpl.get_elt(
                {"url_preview": url_preview_data}
            )
            url_previews_elt <= url_preview_elt

    def handle_url_previews(self, parent_elt=None):
        """Check if URL are presents in a message and show appropriate element

        According to settings, either a preview control panel will be shown to wait for
        user click, or directly the previews, or nothing at all.
        """

        if parent_elt is None:
            parent_elt = document
            chat_message_elts = parent_elt.select(".is-chat-message")
        else:
            chat_message_elts = [parent_elt]
        for message_elt in chat_message_elts:
            urls = self.find_links(message_elt)
            if urls:
                url_previews_elt = message_elt.select_one(".url-previews")
                url_previews_elt.classList.remove("is-hidden")
                preview_control_elt = self.url_preview_control_tpl.get_elt()
                fetch_preview_btn = preview_control_elt.select_one(
                    ".action_fetch_preview"
                )
                fetch_preview_btn.bind(
                    "click",
                    lambda __, previews_elt=url_previews_elt, preview_urls=urls: aio.run(
                        self.add_url_previews(previews_elt, preview_urls)
                    ),
                )
                url_previews_elt <= preview_control_elt

    def open_modal(self, evt):
        modal_image = document.select_one("#modal-image")
        modal_image.src = evt.target.src
        modal_image.alt = evt.target.alt
        modal = document.select_one("#modal")
        modal.classList.add("is-active")

    def close_modal(self, evt):
        modal = document.select_one("#modal")
        modal.classList.remove("is-active")

    def handle_visibility_change(self, evt):
        if (
            document.visibilityState == "hidden"
            and self.new_messages_marker_elt.parent is not None
        ):
            # if there is a new messages marker, we remove it
            self.new_messages_marker_elt.remove()


libervia_web_chat = LiberviaWebChat()

document["message_input"].bind(
    "input", lambda __: libervia_web_chat.auto_resize_message_input()
)
document["message_input"].bind("keydown", libervia_web_chat.on_message_keydown)
document["send_button"].bind(
    "click",
    lambda __: aio.run(libervia_web_chat.send_message())
)
document["attach_button"].bind("click", libervia_web_chat.on_attach_button_click)
document["file_input"].bind("change", libervia_web_chat.on_file_selected)

document.bind("visibilitychange", libervia_web_chat.handle_visibility_change)

bridge.register_signal("message_new", libervia_web_chat._on_message_new)
bridge.register_signal("message_update", libervia_web_chat._on_message_update)