// SPDX-License-Identifier: MIT

import { minimatch } from "minimatch";

import { loadPublicConfig } from "../index.ts";
import { getGraphClient } from "../graph/auth.ts";
import { acquireResourceTokenFromLogin, login, logout } from "../azure/index.ts";
import { getDevOpsApiToken } from "../devops/index.ts";
import {
  listApps,
  listAppPermissions,
  listAppPermissionsResolved,
  listAppGrants,
  listResourcePermissions,
} from "../graph/app.ts";
import { readJsonFromStdin } from "./utils.ts";

type CommandValues = {
  [key: string]: string | boolean | undefined;
  type?: string;
  method?: string;
  url?: string;
  header?: string;
  resources?: string;
  "use-device-code"?: boolean;
  "no-browser"?: boolean;
  browser?: string;
  "browser-profile"?: string;
  all?: boolean;
  "display-name"?: string;
  "app-id"?: string;
  filter?: string;
  resolve?: boolean;
};

type PermissionRow = {
  permissionValue?: string | null;
  permissionDisplayName?: string | null;
};

type DisplayNameRow = {
  displayName?: string | null;
};

function parseHeaderLine(header?: string): { name: string; value: string } | null {
  if (!header || header.trim() === "") {
    return null;
  }

  const separatorIndex = header.indexOf(":");
  if (separatorIndex < 1) {
    throw new Error("--header must be in the format 'Name: Value'");
  }

  const name = header.slice(0, separatorIndex).trim();
  const value = header.slice(separatorIndex + 1).trim();
  if (!name || !value) {
    throw new Error("--header must be in the format 'Name: Value'");
  }

  return { name, value };
}

function hasAuthorizationHeader(headers: Headers): boolean {
  for (const headerName of headers.keys()) {
    if (headerName.toLowerCase() === "authorization") {
      return true;
    }
  }

  return false;
}

async function getAutoAuthorizationHeader(url: URL): Promise<string | null> {
  const host = url.hostname.toLowerCase();
  if (host !== "management.azure.com" && host !== "dev.azure.com") {
    return null;
  }

  const config = await loadPublicConfig();
  if (!config.tenantId) {
    throw new Error("tenantId is required");
  }
  if (!config.clientId) {
    throw new Error("clientId is required");
  }

  if (host === "management.azure.com") {
    const result = await acquireResourceTokenFromLogin({
      tenantId: config.tenantId,
      clientId: config.clientId,
      resource: "arm",
    });
    const accessToken = result?.accessToken;
    if (!accessToken) {
      throw new Error("Failed to obtain AzureRM token");
    }
    return `Bearer ${accessToken}`;
  }

  const accessToken = await getDevOpsApiToken(config.tenantId, config.clientId);
  return `Bearer ${accessToken}`;
}

function filterByPermissionName<T extends PermissionRow>(rows: T[], pattern: string): T[] {
  return rows.filter((item) =>
    minimatch(item.permissionValue ?? "", pattern, { nocase: true })
    || minimatch(item.permissionDisplayName ?? "", pattern, { nocase: true }),
  );
}

function filterByDisplayName<T extends DisplayNameRow>(rows: T[], pattern: string): T[] {
  return rows.filter((item) =>
    minimatch(item.displayName ?? "", pattern, { nocase: true }),
  );
}

async function getGraphClientFromPublicConfig(): Promise<{ client: any }> {
  const config = await loadPublicConfig();
  return getGraphClient({
    tenantId: config.tenantId,
    clientId: config.clientId,
  });
}

async function runTableCommand(): Promise<unknown> {
  return readJsonFromStdin();
}

async function runLoginCommand(values: CommandValues): Promise<unknown> {
  const config = await loadPublicConfig();
  return login({
    tenantId: config.tenantId,
    clientId: config.clientId,
    resourcesCsv: values.resources,
    useDeviceCode: Boolean(values["use-device-code"]),
    noBrowser: Boolean(values["no-browser"]),
    browser: values.browser,
    browserProfile: values["browser-profile"],
  });
}

async function runLogoutCommand(values: CommandValues): Promise<unknown> {
  const config = await loadPublicConfig();
  return logout({
    tenantId: config.tenantId,
    clientId: config.clientId,
    clearAll: Boolean(values.all),
  });
}

async function runListAppsCommand(values: CommandValues): Promise<unknown> {
  const { client } = await getGraphClientFromPublicConfig();
  let result = await listApps(client, {
    displayName: values["display-name"],
    appId: values["app-id"],
  });
  if (values["app-id"] && result.length > 1) {
    throw new Error(`Expected a single app for --app-id ${values["app-id"]}, but got ${result.length}`);
  }
  if (values.filter) {
    result = filterByDisplayName(result, values.filter);
  }
  return result;
}

async function runListAppPermissionsCommand(values: CommandValues): Promise<unknown> {
  if (!values["app-id"]) {
    throw new Error("--app-id is required for list-app-permissions");
  }

  const { client } = await getGraphClientFromPublicConfig();
  let result = values.resolve || values.filter
    ? await listAppPermissionsResolved(client, values["app-id"])
    : await listAppPermissions(client, values["app-id"]);
  if (values.filter) {
    result = filterByPermissionName(result, values.filter);
  }
  return result;
}

async function runListAppGrantsCommand(values: CommandValues): Promise<unknown> {
  if (!values["app-id"]) {
    throw new Error("--app-id is required for list-app-grants");
  }

  const { client } = await getGraphClientFromPublicConfig();
  return listAppGrants(client, values["app-id"]);
}

async function runListResourcePermissionsCommand(values: CommandValues): Promise<unknown> {
  if (!values["app-id"] && !values["display-name"]) {
    throw new Error("--app-id or --display-name is required for list-resource-permissions");
  }
  if (values["app-id"] && values["display-name"]) {
    throw new Error("Use either --app-id or --display-name for list-resource-permissions, not both");
  }

  const { client } = await getGraphClientFromPublicConfig();
  let result = await listResourcePermissions(client, {
    appId: values["app-id"],
    displayName: values["display-name"],
  });
  if (values.filter) {
    result = filterByPermissionName(result, values.filter);
  }
  return result;
}

async function runGetTokenCommand(values: CommandValues): Promise<unknown> {
  const tokenType = (values.type ?? "").toString().trim().toLowerCase();
  if (!tokenType) {
    throw new Error("--type is required for get-token (allowed: azurerm, devops)");
  }

  const config = await loadPublicConfig();
  if (!config.tenantId) {
    throw new Error("tenantId is required");
  }
  if (!config.clientId) {
    throw new Error("clientId is required");
  }

  if (tokenType === "azurerm") {
    const result = await acquireResourceTokenFromLogin({
      tenantId: config.tenantId,
      clientId: config.clientId,
      resource: "arm",
    });

    const accessToken = result?.accessToken;
    if (!accessToken) {
      throw new Error("Failed to obtain AzureRM token");
    }

    return {
      tokenType,
      accessToken,
    };
  }

  if (tokenType === "devops") {
    const accessToken = await getDevOpsApiToken(config.tenantId, config.clientId);
    return {
      tokenType,
      accessToken,
    };
  }

  throw new Error(`Invalid --type '${values.type}'. Allowed: azurerm, devops`);
}

async function runRestCommand(values: CommandValues): Promise<unknown> {
  const method = (values.method ?? "GET").toString().trim().toUpperCase() || "GET";
  const urlValue = (values.url ?? "").toString().trim();

  if (!urlValue) {
    throw new Error("--url is required for rest");
  }

  let targetUrl: URL;
  try {
    targetUrl = new URL(urlValue);
  } catch {
    throw new Error(`Invalid --url '${urlValue}'`);
  }

  const headers = new Headers();
  const customHeader = parseHeaderLine(values.header);
  if (customHeader) {
    headers.set(customHeader.name, customHeader.value);
  }

  if (!hasAuthorizationHeader(headers)) {
    const authorization = await getAutoAuthorizationHeader(targetUrl);
    if (authorization) {
      headers.set("Authorization", authorization);
    }
  }

  const response = await fetch(targetUrl, {
    method,
    headers,
  });

  const contentType = response.headers.get("content-type") ?? "";
  let body: unknown;
  if (contentType.toLowerCase().includes("application/json")) {
    body = await response.json();
  } else {
    body = await response.text();
  }

  return {
    ok: response.ok,
    status: response.status,
    statusText: response.statusText,
    body,
  };
}

export async function runCommand(command: string, values: CommandValues): Promise<unknown> {
  switch (command) {
    case "login":
      return runLoginCommand(values);
    case "logout":
      return runLogoutCommand(values);
    case "table":
      return runTableCommand();
    case "list-apps":
      return runListAppsCommand(values);
    case "list-app-permissions":
      return runListAppPermissionsCommand(values);
    case "list-app-grants":
      return runListAppGrantsCommand(values);
    case "list-resource-permissions":
      return runListResourcePermissionsCommand(values);
    case "get-token":
      return runGetTokenCommand(values);
    case "rest":
      return runRestCommand(values);
    default:
      throw new Error(`Unknown command: ${command}`);
  }
}