/*
Copyright 2019-2024 New Vector Ltd.
Copyright 2019 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 { KeyboardEvent } from "react";

import { Part, CommandPartCreator, PartCreator } from "./parts";
import DocumentPosition from "./position";
import { ICompletion, ISelectionRange } from "../autocomplete/Autocompleter";
import Autocomplete from "../components/views/rooms/Autocomplete";

export interface ICallback {
    replaceParts?: Part[];
    range?: ISelectionRange;
    close?: boolean;
}

export type UpdateCallback = (data: ICallback) => void;
export type GetAutocompleterComponent = () => Autocomplete | null;
export type UpdateQuery = (test: string) => Promise<void>;

export default class AutocompleteWrapperModel {
    private partIndex?: number;

    public constructor(
        private updateCallback: UpdateCallback,
        private getAutocompleterComponent: GetAutocompleterComponent,
        private updateQuery: UpdateQuery,
        private partCreator: PartCreator | CommandPartCreator,
    ) {}

    public onEscape(e: KeyboardEvent): void {
        this.getAutocompleterComponent()?.onEscape(e);
    }

    public close(): void {
        this.updateCallback({ close: true });
    }

    public hasSelection(): boolean {
        return !!this.getAutocompleterComponent()?.hasSelection();
    }

    public hasCompletions(): boolean {
        const ac = this.getAutocompleterComponent();
        return !!ac && ac.countCompletions() > 0;
    }

    public confirmCompletion(): void {
        this.getAutocompleterComponent()?.onConfirmCompletion();
        this.updateCallback({ close: true });
    }

    /**
     * If there is no current autocompletion, start one and move to the first selection.
     */
    public async startSelection(): Promise<void> {
        const acComponent = this.getAutocompleterComponent();
        if (acComponent && acComponent.countCompletions() === 0) {
            // Force completions to show for the text currently entered
            await acComponent.forceComplete();
        }
    }

    public selectPreviousSelection(): void {
        this.getAutocompleterComponent()?.moveSelection(-1);
    }

    public selectNextSelection(): void {
        this.getAutocompleterComponent()?.moveSelection(+1);
    }

    public onPartUpdate(part: Part, pos: DocumentPosition): Promise<void> {
        this.partIndex = pos.index;
        return this.updateQuery(part.text);
    }

    public onComponentConfirm(completion: ICompletion): void {
        this.updateCallback({
            replaceParts: this.partForCompletion(completion),
            close: true,
            range: completion.range,
        });
    }

    private partForCompletion(completion: ICompletion): Part[] {
        const { completionId } = completion;
        const text = completion.completion;
        switch (completion.type) {
            case "room":
                return [this.partCreator.roomPill(text, completionId), this.partCreator.plain(completion.suffix || "")];
            case "at-room":
                return [
                    this.partCreator.atRoomPill(completionId || ""),
                    this.partCreator.plain(completion.suffix || ""),
                ];
            case "user":
                // Insert suffix only if the pill is the part with index 0 - we are at the start of the composer
                return this.partCreator.createMentionParts(this.partIndex === 0, text, completionId || "");
            case "command":
                // command needs special handling for auto complete, but also renders as plain texts
                return [(this.partCreator as CommandPartCreator).command(text)];
            default:
                // used for emoji and other plain text completion replacement
                return this.partCreator.plainWithEmoji(text);
        }
    }
}