import { BodyText } from '@servicetitan/design-system';
import {
    ChatMessageModelFile,
    ChatMessageModelText,
    ChatMessageModelWelcome,
    IChatMessageProps,
    useCustomizationChat,
} from '@servicetitan/titan-chat-ui-common';
import { observer } from 'mobx-react';
import { FC, PropsWithChildren, ReactNode } from 'react';
import { MessageContentFile } from '../message-content/message-content-file';
import { MessageContentText } from '../message-content/message-content-text';
import { ChatMessageTemplateAgent } from './chat-message-template-agent';
import { ChatMessageTemplateUser } from './chat-message-template-user';

/**
 * ChatMessage component provides a default way to render chat messages in the chat UI and contains only most generic
 * components and templates/customizations rendering
 */
export const ChatMessage: FC<IChatMessageProps> = observer(
    ({ message, omitAvatar, omitTimestamp }) => {
        const { messageTemplates, messages } = useCustomizationChat();
        const messageCustomization = messages?.find(c => c.predicate(message));
        const isAgent = message.participant.isAgent;
        const isSystem = Boolean(messageCustomization?.isSystem);

        let messageContentNode: ReactNode | undefined;
        if (messageCustomization?.component) {
            messageContentNode = <messageCustomization.component message={message} />;
        } else {
            // Default message content rendering
            switch (message.type) {
                case 'message':
                case 'welcome':
                    messageContentNode = (
                        <MessageContentText
                            useMarkdown={message.participant.isAgent}
                            message={message as ChatMessageModelText | ChatMessageModelWelcome}
                        />
                    );
                    break;
                case 'file':
                    messageContentNode = (
                        <MessageContentFile message={message as ChatMessageModelFile} />
                    );
                    break;
                default: {
                    messageContentNode = <BodyText>Unknown message type: {message.type}</BodyText>;
                }
            }
        }

        if (!messageContentNode || messageCustomization?.isIgnored) {
            return null;
        }

        if (isSystem) {
            return messageContentNode;
        }

        let ComponentTemplate: FC<PropsWithChildren<IChatMessageProps>>;
        if (isAgent) {
            const template = messageTemplates?.agent;
            ComponentTemplate = template?.predicate(message)
                ? template.component
                : ChatMessageTemplateAgent;
        } else {
            const template = messageTemplates?.user;
            ComponentTemplate = template?.predicate(message)
                ? template.component
                : ChatMessageTemplateUser;
        }
        return (
            <ComponentTemplate
                message={message}
                omitAvatar={omitAvatar}
                omitTimestamp={omitTimestamp}
            >
                {messageContentNode}
            </ComponentTemplate>
        );
    }
);