export type CourseResponse = {
    id: number | string;
    title: string;
    description?: string;
};

export type DocumentSource = {
    document_id: string;
    filename: string;
    excerpt: string;
};

export type ChatMessageResponse = {
    uuid_id: string;
    role: string;
    content: string;
    sources?: DocumentSource[];
    created_at: string;
};

export type ChatSessionResponse = {
    uuid_id: string;
    user_id: string;
    user_name?: string;
    course_id: string;
    course_name?: string;
    title: string;
    message_count: number;
    last_message_at?: string;
    created_at: string;
    updated_at: string;
};

function createLocalMessageId(prefix: string): string {
    if (typeof crypto !== 'undefined' && 'randomUUID' in crypto) {
        return `${prefix}-${crypto.randomUUID()}`;
    }

    return `${prefix}-${Date.now()}-${Math.random().toString(36).slice(2)}`;
}

export function createLocalUserMessage(content: string): ChatMessageResponse {
    return {
        content,
        created_at: new Date().toISOString(),
        role: 'user',
        sources: [],
        uuid_id: createLocalMessageId('local'),
    };
}

export function createLocalAssistantMessage(
    content = '',
): ChatMessageResponse {
    return {
        content,
        created_at: new Date().toISOString(),
        role: 'assistant',
        sources: [],
        uuid_id: createLocalMessageId('local-assistant'),
    };
}