const MONDAY_API = "https://api.monday.com/v2";
const MONDAY_FILE_API = "https://api.monday.com/v2/file";

type MondayColumn = { id: string; title: string; type: string };

async function gql(token: string, query: string, variables?: Record<string, unknown>) {
  const res = await fetch(MONDAY_API, {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      Authorization: token,
    },
    body: JSON.stringify({ query, variables }),
  });
  if (!res.ok) {
    const text = await res.text().catch(() => "");
    throw new Error(`Monday.com API ${res.status}: ${text}`);
  }
  const json = await res.json();
  if (json.errors?.length) {
    throw new Error(`Monday.com GraphQL: ${json.errors[0].message}`);
  }
  return json.data;
}

export async function fetchBoardColumns(token: string, boardId: string): Promise<MondayColumn[]> {
  const data = await gql(token, `
    query ($boardId: [ID!]!) {
      boards(ids: $boardId) {
        columns { id title type }
      }
    }
  `, { boardId: [boardId] });
  return data?.boards?.[0]?.columns ?? [];
}

export async function createItem(
  token: string,
  boardId: string,
  itemName: string,
  columnValues: Record<string, unknown>
): Promise<string> {
  const data = await gql(token, `
    mutation ($boardId: ID!, $itemName: String!, $columnValues: JSON!) {
      create_item(
        board_id: $boardId,
        item_name: $itemName,
        column_values: $columnValues,
        create_labels_if_missing: true
      ) { id }
    }
  `, {
    boardId,
    itemName,
    columnValues: JSON.stringify(columnValues),
  });
  return String(data.create_item.id);
}

export async function updateItem(
  token: string,
  boardId: string,
  itemId: string,
  columnValues: Record<string, unknown>
): Promise<void> {
  await gql(token, `
    mutation ($boardId: ID!, $itemId: ID!, $columnValues: JSON!) {
      change_multiple_column_values(
        board_id: $boardId,
        item_id: $itemId,
        column_values: $columnValues,
        create_labels_if_missing: true
      ) { id }
    }
  `, {
    boardId,
    itemId,
    columnValues: JSON.stringify(columnValues),
  });
}

export async function uploadFileToItem(
  token: string,
  itemId: string,
  columnId: string,
  fileBuffer: Buffer,
  fileName: string
): Promise<void> {
  const query = `mutation ($file: File!) { add_file_to_column(file: $file, item_id: ${itemId}, column_id: "${columnId}") { id } }`;

  const form = new FormData();
  form.append("query", query);
  form.append("variables[file]", new Blob([new Uint8Array(fileBuffer)]), fileName);

  const res = await fetch(MONDAY_FILE_API, {
    method: "POST",
    headers: { Authorization: token },
    body: form,
  });
  if (!res.ok) {
    const text = await res.text().catch(() => "");
    throw new Error(`Monday.com file upload ${res.status}: ${text}`);
  }
}

type ItemColumnValue = { id: string; text: string; value: string | null };

export async function readItem(
  token: string,
  itemId: string
): Promise<{ name: string; columnValues: ItemColumnValue[] } | null> {
  const data = await gql(token, `
    query ($itemId: [ID!]!) {
      items(ids: $itemId) {
        name
        column_values { id text value }
      }
    }
  `, { itemId: [itemId] });
  const item = data?.items?.[0];
  if (!item) return null;
  return {
    name: item.name,
    columnValues: item.column_values.map((cv: { id: string; text: string; value: string | null }) => ({
      id: cv.id,
      text: cv.text,
      value: cv.value,
    })),
  };
}

export function mapCardToColumnValues(
  card: Record<string, unknown>,
  columnMap: Record<string, string>
): Record<string, unknown> {
  const values: Record<string, unknown> = {};

  for (const [cardField, colId] of Object.entries(columnMap)) {
    if (!colId || !cardField) continue;
    const val = card[cardField];
    if (val === null || val === undefined) continue;
    values[colId] = String(val);
  }

  return values;
}

export function mapItemToCardFields(
  columnValues: ItemColumnValue[],
  columnMap: Record<string, string>
): Record<string, string> {
  const reverseMap: Record<string, string> = {};
  for (const [cardField, colId] of Object.entries(columnMap)) {
    reverseMap[colId] = cardField;
  }

  const cardData: Record<string, string> = {};
  for (const cv of columnValues) {
    const cardField = reverseMap[cv.id];
    if (cardField && cv.text) {
      cardData[cardField] = cv.text;
    }
  }
  return cardData;
}

export async function createWebhookSubscription(
  token: string,
  boardId: string,
  callbackUrl: string
): Promise<string> {
  const data = await gql(token, `
    mutation ($boardId: ID!, $url: String!) {
      create_webhook(board_id: $boardId, url: $url, event: change_column_value) { id }
    }
  `, { boardId, url: callbackUrl });
  return String(data.create_webhook.id);
}

export async function deleteWebhookSubscription(
  token: string,
  webhookId: string
): Promise<void> {
  await gql(token, `
    mutation ($webhookId: ID!) {
      delete_webhook(id: $webhookId) { id }
    }
  `, { webhookId });
}