/*
Copyright 2024 New Vector Ltd.
Copyright 2019-2021 The Matrix.org Foundation C.I.C.

SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only
Please see LICENSE files in the repository root for full details.
*/

import React, { createRef, KeyboardEvent } from "react";
import classNames from "classnames";
import { EventStatus, MatrixEvent, Room, MsgType } from "matrix-js-sdk/src/matrix";
import { logger } from "matrix-js-sdk/src/logger";
import { Composer as ComposerEvent } from "@matrix-org/analytics-events/types/typescript/Composer";
import { ReplacementEvent, RoomMessageEventContent, RoomMessageTextEventContent } from "matrix-js-sdk/src/types";

import { _t } from "../../../languageHandler";
import dis from "../../../dispatcher/dispatcher";
import EditorModel from "../../../editor/model";
import { getCaretOffsetAndText } from "../../../editor/dom";
import { htmlSerializeIfNeeded, textSerialize, containsEmote, stripEmoteCommand } from "../../../editor/serialize";
import { findEditableEvent } from "../../../utils/EventUtils";
import { parseEvent } from "../../../editor/deserialize";
import { CommandPartCreator, Part, PartCreator, SerializedPart } from "../../../editor/parts";
import EditorStateTransfer from "../../../utils/EditorStateTransfer";
import BasicMessageComposer, { REGEX_EMOTICON } from "./BasicMessageComposer";
import { CommandCategories } from "../../../SlashCommands";
import { Action } from "../../../dispatcher/actions";
import { getKeyBindingsManager } from "../../../KeyBindingsManager";
import SendHistoryManager from "../../../SendHistoryManager";
import { ActionPayload } from "../../../dispatcher/payloads";
import AccessibleButton from "../elements/AccessibleButton";
import { createRedactEventDialog } from "../dialogs/ConfirmRedactDialog";
import SettingsStore from "../../../settings/SettingsStore";
import { withMatrixClientHOC, MatrixClientProps } from "../../../contexts/MatrixClientContext";
import RoomContext from "../../../contexts/RoomContext";
import { ComposerType } from "../../../dispatcher/payloads/ComposerInsertPayload";
import { getSlashCommand, isSlashCommand, runSlashCommand, shouldSendAnyway } from "../../../editor/commands";
import { KeyBindingAction } from "../../../accessibility/KeyboardShortcuts";
import { PosthogAnalytics } from "../../../PosthogAnalytics";
import { editorRoomKey, editorStateKey } from "../../../Editing";
import DocumentOffset from "../../../editor/offset";
import { attachMentions, attachRelation } from "./SendMessageComposer";
import { filterBoolean } from "../../../utils/arrays";
import { MatrixClientPeg } from "../../../MatrixClientPeg";

function getHtmlReplyFallback(mxEvent: MatrixEvent): string {
    const html = mxEvent.getContent().formatted_body;
    if (!html) {
        return "";
    }
    const rootNode = new DOMParser().parseFromString(html, "text/html").body;
    const mxReply = rootNode.querySelector("mx-reply");
    return (mxReply && mxReply.outerHTML) || "";
}

function getTextReplyFallback(mxEvent: MatrixEvent): string {
    const body: string = mxEvent.getContent().body;
    const lines = body.split("\n").map((l) => l.trim());
    if (lines.length > 2 && lines[0].startsWith("> ") && lines[1].length === 0) {
        return `${lines[0]}\n\n`;
    }
    return "";
}

// exported for tests
export function createEditContent(
    model: EditorModel,
    editedEvent: MatrixEvent,
    replyToEvent?: MatrixEvent,
): RoomMessageEventContent {
    const isEmote = containsEmote(model);
    if (isEmote) {
        model = stripEmoteCommand(model);
    }
    const isReply = !!editedEvent.replyEventId;
    let plainPrefix = "";
    let htmlPrefix = "";

    if (isReply) {
        plainPrefix = getTextReplyFallback(editedEvent);
        htmlPrefix = getHtmlReplyFallback(editedEvent);
    }

    const body = textSerialize(model);

    const newContent: RoomMessageEventContent = {
        msgtype: isEmote ? MsgType.Emote : MsgType.Text,
        body: body,
    };
    const contentBody: RoomMessageTextEventContent & Omit<ReplacementEvent<RoomMessageEventContent>, "m.relates_to"> = {
        "msgtype": newContent.msgtype,
        "body": `${plainPrefix} * ${body}`,
        "m.new_content": newContent,
    };

    const formattedBody = htmlSerializeIfNeeded(model, {
        forceHTML: isReply,
        useMarkdown: SettingsStore.getValue("MessageComposerInput.useMarkdown"),
    });
    if (formattedBody) {
        newContent.format = "org.matrix.custom.html";
        newContent.formatted_body = formattedBody;
        contentBody.format = newContent.format;
        contentBody.formatted_body = `${htmlPrefix} * ${formattedBody}`;
    }

    // Build the mentions properties for both the content and new_content.
    attachMentions(editedEvent.sender!.userId, contentBody, model, replyToEvent, editedEvent.getContent());
    attachRelation(contentBody, { rel_type: "m.replace", event_id: editedEvent.getId() });

    return contentBody as RoomMessageEventContent;
}

interface IEditMessageComposerProps extends MatrixClientProps {
    editState: EditorStateTransfer;
    className?: string;
}
interface IState {
    saveDisabled: boolean;
}

class EditMessageComposer extends React.Component<IEditMessageComposerProps, IState> {
    public static contextType = RoomContext;
    public declare context: React.ContextType<typeof RoomContext>;

    private readonly editorRef = createRef<BasicMessageComposer>();
    private readonly dispatcherRef: string;
    private readonly replyToEvent?: MatrixEvent;
    private model!: EditorModel;

    public constructor(props: IEditMessageComposerProps, context: React.ContextType<typeof RoomContext>) {
        super(props, context);

        const isRestored = this.createEditorModel();
        const ev = this.props.editState.getEvent();

        this.replyToEvent = ev.replyEventId ? this.context.room?.findEventById(ev.replyEventId) : undefined;

        const editContent = createEditContent(this.model, ev, this.replyToEvent);
        this.state = {
            saveDisabled: !isRestored || !this.isContentModified(editContent["m.new_content"]!),
        };

        window.addEventListener("beforeunload", this.saveStoredEditorState);
        this.dispatcherRef = dis.register(this.onAction);
    }

    private getRoom(): Room {
        if (!this.context.room) {
            throw new Error(`Cannot render without room`);
        }
        return this.context.room;
    }

    private onKeyDown = (event: KeyboardEvent): void => {
        // ignore any keypress while doing IME compositions
        if (this.editorRef.current?.isComposing(event)) {
            return;
        }
        const action = getKeyBindingsManager().getMessageComposerAction(event);
        switch (action) {
            case KeyBindingAction.SendMessage:
                this.sendEdit();
                event.stopPropagation();
                event.preventDefault();
                break;
            case KeyBindingAction.CancelReplyOrEdit:
                event.stopPropagation();
                this.cancelEdit();
                break;
            case KeyBindingAction.EditPrevMessage: {
                if (this.editorRef.current?.isModified() || !this.editorRef.current?.isCaretAtStart()) {
                    return;
                }
                const previousEvent = findEditableEvent({
                    events: this.events,
                    isForward: false,
                    fromEventId: this.props.editState.getEvent().getId(),
                    matrixClient: MatrixClientPeg.safeGet(),
                });
                if (previousEvent) {
                    dis.dispatch({
                        action: Action.EditEvent,
                        event: previousEvent,
                        timelineRenderingType: this.context.timelineRenderingType,
                    });
                    event.preventDefault();
                }
                break;
            }
            case KeyBindingAction.EditNextMessage: {
                if (this.editorRef.current?.isModified() || !this.editorRef.current?.isCaretAtEnd()) {
                    return;
                }
                const nextEvent = findEditableEvent({
                    events: this.events,
                    isForward: true,
                    fromEventId: this.props.editState.getEvent().getId(),
                    matrixClient: MatrixClientPeg.safeGet(),
                });
                if (nextEvent) {
                    dis.dispatch({
                        action: Action.EditEvent,
                        event: nextEvent,
                        timelineRenderingType: this.context.timelineRenderingType,
                    });
                } else {
                    this.cancelEdit();
                }
                event.preventDefault();
                break;
            }
        }
    };

    private endEdit(): void {
        localStorage.removeItem(this.editorRoomKey);
        localStorage.removeItem(this.editorStateKey);

        // close the event editing and focus composer
        dis.dispatch({
            action: Action.EditEvent,
            event: null,
            timelineRenderingType: this.context.timelineRenderingType,
        });
        dis.dispatch({
            action: Action.FocusSendMessageComposer,
            context: this.context.timelineRenderingType,
        });
    }

    private get editorRoomKey(): string {
        return editorRoomKey(this.props.editState.getEvent().getRoomId()!, this.context.timelineRenderingType);
    }

    private get editorStateKey(): string {
        return editorStateKey(this.props.editState.getEvent().getId()!);
    }

    private get events(): MatrixEvent[] {
        const liveTimelineEvents = this.context.liveTimeline?.getEvents();
        const room = this.getRoom();
        if (!liveTimelineEvents || !room) return [];
        const pendingEvents = room.getPendingEvents();
        const isInThread = Boolean(this.props.editState.getEvent().getThread());
        return liveTimelineEvents.concat(isInThread ? [] : pendingEvents);
    }

    private cancelEdit = (): void => {
        this.endEdit();
    };

    private get shouldSaveStoredEditorState(): boolean {
        return localStorage.getItem(this.editorRoomKey) !== null;
    }

    private restoreStoredEditorState(partCreator: PartCreator): Part[] | undefined {
        const json = localStorage.getItem(this.editorStateKey);
        if (json) {
            try {
                const { parts: serializedParts } = JSON.parse(json);
                const parts: Part[] = serializedParts.map((p: SerializedPart) => partCreator.deserializePart(p));
                return parts;
            } catch (e) {
                logger.error("Error parsing editing state: ", e);
            }
        }
    }

    private clearPreviousEdit(): void {
        if (localStorage.getItem(this.editorRoomKey)) {
            localStorage.removeItem(`mx_edit_state_${localStorage.getItem(this.editorRoomKey)}`);
        }
    }

    private saveStoredEditorState = (): void => {
        const item = SendHistoryManager.createItem(this.model);
        this.clearPreviousEdit();
        localStorage.setItem(this.editorRoomKey, this.props.editState.getEvent().getId()!);
        localStorage.setItem(this.editorStateKey, JSON.stringify(item));
    };

    private isContentModified(newContent: RoomMessageEventContent): boolean {
        // if nothing has changed then bail
        const oldContent = this.props.editState.getEvent().getContent<RoomMessageEventContent>();
        if (
            oldContent["msgtype"] === newContent["msgtype"] &&
            oldContent["body"] === newContent["body"] &&
            (oldContent as RoomMessageTextEventContent)["format"] ===
                (newContent as RoomMessageTextEventContent)["format"] &&
            (oldContent as RoomMessageTextEventContent)["formatted_body"] ===
                (newContent as RoomMessageTextEventContent)["formatted_body"]
        ) {
            return false;
        }
        return true;
    }

    private sendEdit = async (): Promise<void> => {
        if (this.state.saveDisabled) return;

        const editedEvent = this.props.editState.getEvent();

        PosthogAnalytics.instance.trackEvent<ComposerEvent>({
            eventName: "Composer",
            isEditing: true,
            messageType: "Text",
            inThread: !!editedEvent?.getThread(),
            isReply: !!editedEvent.replyEventId,
        });

        // Replace emoticon at the end of the message
        if (SettingsStore.getValue("MessageComposerInput.autoReplaceEmoji") && this.editorRef.current) {
            const caret = this.editorRef.current.getCaret();
            const position = this.model.positionForOffset(caret.offset, caret.atNodeEnd);
            this.editorRef.current.replaceEmoticon(position, REGEX_EMOTICON);
        }
        const editContent = createEditContent(this.model, editedEvent, this.replyToEvent);
        const newContent = editContent["m.new_content"]!;

        let shouldSend = true;

        if (newContent?.body === "") {
            this.cancelPreviousPendingEdit();
            createRedactEventDialog({
                mxEvent: editedEvent,
                onCloseDialog: () => {
                    this.cancelEdit();
                },
            });
            return;
        }

        // If content is modified then send an updated event into the room
        if (this.isContentModified(newContent)) {
            const roomId = editedEvent.getRoomId()!;
            if (!containsEmote(this.model) && isSlashCommand(this.model)) {
                const [cmd, args, commandText] = getSlashCommand(this.model);
                if (cmd) {
                    const threadId = editedEvent?.getThread()?.id || null;
                    const [content, commandSuccessful] = await runSlashCommand(
                        MatrixClientPeg.safeGet(),
                        cmd,
                        args,
                        roomId,
                        threadId,
                    );
                    if (!commandSuccessful) {
                        return; // errored
                    }

                    if (cmd.category === CommandCategories.messages || cmd.category === CommandCategories.effects) {
                        editContent["m.new_content"] = content!;
                    } else {
                        shouldSend = false;
                    }
                } else {
                    const sendAnyway = await shouldSendAnyway(commandText);
                    // re-focus the composer after QuestionDialog is closed
                    dis.dispatch({
                        action: Action.FocusAComposer,
                        context: this.context.timelineRenderingType,
                    });
                    // if !sendAnyway bail to let the user edit the composer and try again
                    if (!sendAnyway) return;
                }
            }
            if (shouldSend) {
                this.cancelPreviousPendingEdit();

                const event = this.props.editState.getEvent();
                const threadId = event.threadRootId || null;

                this.props.mxClient.sendMessage(roomId, threadId, editContent);
                dis.dispatch({ action: "message_sent" });
            }
        }

        this.endEdit();
    };

    private cancelPreviousPendingEdit(): void {
        const originalEvent = this.props.editState.getEvent();
        const previousEdit = originalEvent.replacingEvent();
        if (
            previousEdit &&
            (previousEdit.status === EventStatus.QUEUED || previousEdit.status === EventStatus.NOT_SENT)
        ) {
            this.props.mxClient.cancelPendingEvent(previousEdit);
        }
    }

    public componentWillUnmount(): void {
        // store caret and serialized parts in the
        // editorstate so it can be restored when the remote echo event tile gets rendered
        // in case we're currently editing a pending event
        const sel = document.getSelection()!;
        let caret: DocumentOffset | undefined;
        if (sel.focusNode && this.editorRef.current?.editorRef.current) {
            caret = getCaretOffsetAndText(this.editorRef.current.editorRef.current, sel).caret;
        }
        const parts = this.model.serializeParts();
        // if caret is undefined because for some reason there isn't a valid selection,
        // then when mounting the editor again with the same editor state,
        // it will set the cursor at the end.
        this.props.editState.setEditorState(caret ?? null, parts);
        window.removeEventListener("beforeunload", this.saveStoredEditorState);
        if (this.shouldSaveStoredEditorState) {
            this.saveStoredEditorState();
        }
        dis.unregister(this.dispatcherRef);
    }

    private createEditorModel(): boolean {
        const { editState } = this.props;
        const room = this.getRoom();
        const partCreator = new CommandPartCreator(room, this.props.mxClient);

        let parts: Part[];
        let isRestored = false;
        if (editState.hasEditorState()) {
            // if restoring state from a previous editor,
            // restore serialized parts from the state
            // (editState.hasEditorState() checks getSerializedParts is not null)
            parts = filterBoolean<Part>(editState.getSerializedParts()!.map((p) => partCreator.deserializePart(p)));
        } else {
            // otherwise, either restore serialized parts from localStorage or parse the body of the event
            const restoredParts = this.restoreStoredEditorState(partCreator);
            parts =
                restoredParts ||
                parseEvent(editState.getEvent(), partCreator, {
                    shouldEscape: SettingsStore.getValue("MessageComposerInput.useMarkdown"),
                });
            isRestored = !!restoredParts;
        }
        this.model = new EditorModel(parts, partCreator);
        this.saveStoredEditorState();

        return isRestored;
    }

    private onChange = (): void => {
        if (!this.state.saveDisabled || !this.editorRef.current?.isModified()) {
            return;
        }

        this.setState({
            saveDisabled: false,
        });
    };

    private onAction = (payload: ActionPayload): void => {
        if (!this.editorRef.current) return;

        if (payload.action === Action.ComposerInsert) {
            if (payload.timelineRenderingType !== this.context.timelineRenderingType) return;
            if (payload.composerType !== ComposerType.Edit) return;

            if (payload.userId) {
                this.editorRef.current?.insertMention(payload.userId);
            } else if (payload.event) {
                this.editorRef.current?.insertQuotedMessage(payload.event);
            } else if (payload.text) {
                this.editorRef.current?.insertPlaintext(payload.text);
            }
        } else if (payload.action === Action.FocusEditMessageComposer) {
            this.editorRef.current.focus();
        }
    };

    public render(): React.ReactNode {
        const room = this.getRoom();
        if (!room) return null;

        return (
            <div className={classNames("mx_EditMessageComposer", this.props.className)} onKeyDown={this.onKeyDown}>
                <BasicMessageComposer
                    ref={this.editorRef}
                    model={this.model}
                    room={room}
                    threadId={this.props.editState?.getEvent()?.getThread()?.id}
                    initialCaret={this.props.editState.getCaret() ?? undefined}
                    label={_t("composer|edit_composer_label")}
                    onChange={this.onChange}
                />
                <div className="mx_EditMessageComposer_buttons">
                    <AccessibleButton kind="secondary" onClick={this.cancelEdit}>
                        {_t("action|cancel")}
                    </AccessibleButton>
                    <AccessibleButton kind="primary" onClick={this.sendEdit} disabled={this.state.saveDisabled}>
                        {_t("action|save")}
                    </AccessibleButton>
                </div>
            </div>
        );
    }
}

const EditMessageComposerWithMatrixClient = withMatrixClientHOC(EditMessageComposer);
export default EditMessageComposerWithMatrixClient;