import type { MessagesDataSource, MessagesSnapshot, SendMessageInput } from './messages-module.js';

interface Options {
  readonly fetcher?: typeof fetch;
}

function record(value: unknown): Record<string, unknown> | undefined {
  return value !== null && typeof value === 'object' && !Array.isArray(value)
    ? (value as Record<string, unknown>)
    : undefined;
}

export function createMessagesApiDataSource(options: Options = {}): MessagesDataSource {
  const fetcher = options.fetcher ?? fetch;
  return {
    async load(instanceId, signal): Promise<MessagesSnapshot> {
      const response = await fetcher(
        `/api/v1/instances/${encodeURIComponent(instanceId)}/messages?limit=50&offset=0`,
        { headers: { accept: 'application/json' }, credentials: 'same-origin', signal },
      );
      if (!response.ok) throw new Error('message load failed');
      const root = record(await response.json());
      if (!Array.isArray(root?.messages)) throw new Error('message load failed');
      return {
        messages: root.messages.flatMap((item) => {
          const value = record(item);
          return typeof value?.id === 'string' &&
            typeof value.phoneNumber === 'string' &&
            typeof value.content === 'string' &&
            typeof value.timestamp === 'string' &&
            typeof value.status === 'string' &&
            typeof value.direction === 'string'
            ? [
                {
                  id: value.id,
                  phoneNumber: value.phoneNumber,
                  content: value.content,
                  timestamp: value.timestamp,
                  status: value.status,
                  direction: value.direction,
                },
              ]
            : [];
        }),
      };
    },
    async send(instanceId: string, input: SendMessageInput): Promise<void> {
      const response = await fetcher(
        `/api/v1/instances/${encodeURIComponent(instanceId)}/messages/send`,
        {
          method: 'POST',
          headers: { accept: 'application/json', 'content-type': 'application/json' },
          credentials: 'same-origin',
          body: JSON.stringify(input),
        },
      );
      if (!response.ok) throw new Error('message send failed');
    },
  };
}