import * as fs from "fs";
import * as os from "os";
import * as path from "path";

import * as core from "@actions/core";
import * as toolrunner from "@actions/exec/lib/toolrunner";
import * as safeWhich from "@chrisgavin/safe-which";

import * as api from "./api-client";
import { Config } from "./config-utils";
import * as sharedEnv from "./shared-environment";
import {
  doesDirectoryExist,
  getCachedCodeQlVersion,
  getCodeQLDatabasePath,
  getRequiredEnvParam,
  GITHUB_DOTCOM_URL,
  isHTTPError,
  isInTestMode,
  UserError,
} from "./util";
import { getWorkflowPath } from "./workflow";

// eslint-disable-next-line import/no-commonjs
const pkg = require("../package.json");

/**
 * Wrapper around core.getInput for inputs that always have a value.
 * Also see getOptionalInput.
 *
 * This allows us to get stronger type checking of required/optional inputs.
 */
export function getRequiredInput(name: string): string {
  return core.getInput(name, { required: true });
}

/**
 * Wrapper around core.getInput that converts empty inputs to undefined.
 * Also see getRequiredInput.
 *
 * This allows us to get stronger type checking of required/optional inputs.
 */
export const getOptionalInput = function (name: string): string | undefined {
  const value = core.getInput(name);
  return value.length > 0 ? value : undefined;
};

export function getTemporaryDirectory(): string {
  const value = process.env["CODEQL_ACTION_TEMP"];
  return value !== undefined && value !== ""
    ? value
    : getRequiredEnvParam("RUNNER_TEMP");
}

/**
 * Gets the SHA of the commit that is currently checked out.
 */
export const getCommitOid = async function (
  checkoutPath: string,
  ref = "HEAD"
): Promise<string> {
  // Try to use git to get the current commit SHA. If that fails then
  // log but otherwise silently fall back to using the SHA from the environment.
  // The only time these two values will differ is during analysis of a PR when
  // the workflow has changed the current commit to the head commit instead of
  // the merge commit, which must mean that git is available.
  // Even if this does go wrong, it's not a huge problem for the alerts to
  // reported on the merge commit.
  try {
    let commitOid = "";
    await new toolrunner.ToolRunner(
      await safeWhich.safeWhich("git"),
      ["rev-parse", ref],
      {
        silent: true,
        listeners: {
          stdout: (data) => {
            commitOid += data.toString();
          },
          stderr: (data) => {
            process.stderr.write(data);
          },
        },
        cwd: checkoutPath,
      }
    ).exec();
    return commitOid.trim();
  } catch (e) {
    core.info(
      `Failed to call git to get current commit. Continuing with data from environment or input: ${e}`
    );
    core.info((e as Error).stack || "NO STACK");
    return getOptionalInput("sha") || getRequiredEnvParam("GITHUB_SHA");
  }
};

/**
 * If the action was triggered by a pull request, determine the commit sha of the merge base.
 * Returns undefined if run by other triggers or the merge base cannot be determined.
 */
export const determineMergeBaseCommitOid = async function (): Promise<
  string | undefined
> {
  if (workflowEventName() !== "pull_request") {
    return undefined;
  }

  const mergeSha = getRequiredEnvParam("GITHUB_SHA");
  const checkoutPath = getOptionalInput("checkout_path");

  try {
    let commitOid = "";
    let baseOid = "";
    let headOid = "";

    await new toolrunner.ToolRunner(
      await safeWhich.safeWhich("git"),
      ["show", "-s", "--format=raw", mergeSha],
      {
        silent: true,
        listeners: {
          stdline: (data) => {
            if (data.startsWith("commit ") && commitOid === "") {
              commitOid = data.substring(7);
            } else if (data.startsWith("parent ")) {
              if (baseOid === "") {
                baseOid = data.substring(7);
              } else if (headOid === "") {
                headOid = data.substring(7);
              }
            }
          },
          stderr: (data) => {
            process.stderr.write(data);
          },
        },
        cwd: checkoutPath,
      }
    ).exec();

    // Let's confirm our assumptions: We had a merge commit and the parsed parent data looks correct
    if (
      commitOid === mergeSha &&
      headOid.length === 40 &&
      baseOid.length === 40
    ) {
      return baseOid;
    }
    return undefined;
  } catch (e) {
    core.info(
      `Failed to call git to determine merge base. Continuing with data from environment: ${e}`
    );
    core.info((e as Error).stack || "NO STACK");
    return undefined;
  }
};

/**
 * Get the analysis key parameter for the current job.
 *
 * This will combine the workflow path and current job name.
 * Computing this the first time requires making requests to
 * the github API, but after that the result will be cached.
 */
export async function getAnalysisKey(): Promise<string> {
  const analysisKeyEnvVar = "CODEQL_ACTION_ANALYSIS_KEY";

  let analysisKey = process.env[analysisKeyEnvVar];
  if (analysisKey !== undefined) {
    return analysisKey;
  }

  const workflowPath = await getWorkflowPath();
  const jobName = getRequiredEnvParam("GITHUB_JOB");

  analysisKey = `${workflowPath}:${jobName}`;
  core.exportVariable(analysisKeyEnvVar, analysisKey);
  return analysisKey;
}

export async function getAutomationID(): Promise<string> {
  const analysis_key = await getAnalysisKey();
  const environment = getRequiredInput("matrix");

  return computeAutomationID(analysis_key, environment);
}

export function computeAutomationID(
  analysis_key: string,
  environment: string | undefined
): string {
  let automationID = `${analysis_key}/`;

  // the id has to be deterministic so we sort the fields
  if (environment !== undefined && environment !== "null") {
    const environmentObject = JSON.parse(environment);
    for (const entry of Object.entries(environmentObject).sort()) {
      if (typeof entry[1] === "string") {
        automationID += `${entry[0]}:${entry[1]}/`;
      } else {
        // In code scanning we just handle the string values,
        // the rest get converted to the empty string
        automationID += `${entry[0]}:/`;
      }
    }
  }

  return automationID;
}

/**
 * Get the ref currently being analyzed.
 */
export async function getRef(): Promise<string> {
  // Will be in the form "refs/heads/master" on a push event
  // or in the form "refs/pull/N/merge" on a pull_request event
  const refInput = getOptionalInput("ref");
  const shaInput = getOptionalInput("sha");
  const checkoutPath =
    getOptionalInput("checkout_path") ||
    getOptionalInput("source-root") ||
    getRequiredEnvParam("GITHUB_WORKSPACE");

  const hasRefInput = !!refInput;
  const hasShaInput = !!shaInput;
  // If one of 'ref' or 'sha' are provided, both are required
  if ((hasRefInput || hasShaInput) && !(hasRefInput && hasShaInput)) {
    throw new Error(
      "Both 'ref' and 'sha' are required if one of them is provided."
    );
  }

  const ref = refInput || getRefFromEnv();
  const sha = shaInput || getRequiredEnvParam("GITHUB_SHA");

  // If the ref is a user-provided input, we have to skip logic
  // and assume that it is really where they want to upload the results.
  if (refInput) {
    return refInput;
  }

  // For pull request refs we want to detect whether the workflow
  // has run `git checkout HEAD^2` to analyze the 'head' ref rather
  // than the 'merge' ref. If so, we want to convert the ref that
  // we report back.
  const pull_ref_regex = /refs\/pull\/(\d+)\/merge/;
  if (!pull_ref_regex.test(ref)) {
    return ref;
  }

  const head = await getCommitOid(checkoutPath, "HEAD");

  // in actions/checkout@v2+ we can check if git rev-parse HEAD == GITHUB_SHA
  // in actions/checkout@v1 this may not be true as it checks out the repository
  // using GITHUB_REF. There is a subtle race condition where
  // git rev-parse GITHUB_REF != GITHUB_SHA, so we must check
  // git rev-parse GITHUB_REF == git rev-parse HEAD instead.
  const hasChangedRef =
    sha !== head &&
    (await getCommitOid(
      checkoutPath,
      ref.replace(/^refs\/pull\//, "refs/remotes/pull/")
    )) !== head;

  if (hasChangedRef) {
    const newRef = ref.replace(pull_ref_regex, "refs/pull/$1/head");
    core.debug(
      `No longer on merge commit, rewriting ref from ${ref} to ${newRef}.`
    );
    return newRef;
  } else {
    return ref;
  }
}

function getRefFromEnv(): string {
  // To workaround a limitation of Actions dynamic workflows not setting
  // the GITHUB_REF in some cases, we accept also the ref within the
  // CODE_SCANNING_REF variable. When possible, however, we prefer to use
  // the GITHUB_REF as that is a protected variable and cannot be overwritten.
  let refEnv: string;
  try {
    refEnv = getRequiredEnvParam("GITHUB_REF");
  } catch (e) {
    // If the GITHUB_REF is not set, we try to rescue by getting the
    // CODE_SCANNING_REF.
    const maybeRef = process.env["CODE_SCANNING_REF"];
    if (maybeRef === undefined || maybeRef.length === 0) {
      throw e;
    }
    refEnv = maybeRef;
  }
  return refEnv;
}

type ActionName = "init" | "autobuild" | "finish" | "upload-sarif";
type ActionStatus =
  | "starting"
  | "aborted"
  | "success"
  | "failure"
  | "user-error";

export interface StatusReportBase {
  /** ID of the workflow run containing the action run. */
  workflow_run_id: number;
  /** Workflow name. Converted to analysis_name further down the pipeline.. */
  workflow_name: string;
  /** Job name from the workflow. */
  job_name: string;
  /** Analysis key, normally composed from the workflow path and job name. */
  analysis_key: string;
  /** Value of the matrix for this instantiation of the job. */
  matrix_vars?: string;
  /** Commit oid that the workflow was triggered on. */
  commit_oid: string;
  /** Ref that the workflow was triggered on. */
  ref: string;
  /** Name of the action being executed. */
  action_name: ActionName;
  /** Version of the action being executed, as a ref. */
  action_ref?: string;
  /** Version of the action being executed, as a commit oid. */
  action_oid: string;
  /** Time the first action started. Normally the init action. */
  started_at: string;
  /** Time this action started. */
  action_started_at: string;
  /** Time this action completed, or undefined if not yet completed. */
  completed_at?: string;
  /** State this action is currently in. */
  status: ActionStatus;
  /**
   * Testing environment: Set if non-production environment.
   * The server accepts one of the following values:
   *  `["", "qa-rc", "qa-rc-1", "qa-rc-2", "qa-experiment-1", "qa-experiment-2", "qa-experiment-3"]`.
   */
  testing_environment: string;
  /**
   * Information about the enablement of the ML-powered JS query pack.
   *
   * @see {@link util.getMlPoweredJsQueriesStatus}
   */
  ml_powered_javascript_queries?: string;
  /** Cause of the failure (or undefined if status is not failure). */
  cause?: string;
  /** Stack trace of the failure (or undefined if status is not failure). */
  exception?: string;
  /** Action runner operating system (context runner.os). */
  runner_os: string;
  /** Action runner hardware architecture (context runner.arch). */
  runner_arch?: string;
  /** Action runner operating system release (x.y.z from os.release()). */
  runner_os_release?: string;
  /** Action version (x.y.z from package.json). */
  action_version: string;
  /** CodeQL CLI version (x.y.z from the CLI). */
  codeql_version?: string;
}

export interface DatabaseCreationTimings {
  scanned_language_extraction_duration_ms?: number;
  trap_import_duration_ms?: number;
}

export function getActionsStatus(
  error?: unknown,
  otherFailureCause?: string
): ActionStatus {
  if (error || otherFailureCause) {
    return error instanceof UserError ? "user-error" : "failure";
  } else {
    return "success";
  }
}

/**
 * Compose a StatusReport.
 *
 * @param actionName The name of the action, e.g. 'init', 'finish', 'upload-sarif'
 * @param status The status. Must be 'success', 'failure', or 'starting'
 * @param startedAt The time this action started executing.
 * @param cause  Cause of failure (only supply if status is 'failure')
 * @param exception Exception (only supply if status is 'failure')
 */
export async function createStatusReportBase(
  actionName: ActionName,
  status: ActionStatus,
  actionStartedAt: Date,
  cause?: string,
  exception?: string
): Promise<StatusReportBase> {
  const commitOid = getOptionalInput("sha") || process.env["GITHUB_SHA"] || "";
  const ref = await getRef();
  const workflowRunIDStr = process.env["GITHUB_RUN_ID"];
  let workflowRunID = -1;
  if (workflowRunIDStr) {
    workflowRunID = parseInt(workflowRunIDStr, 10);
  }
  const workflowName = process.env["GITHUB_WORKFLOW"] || "";
  const jobName = process.env["GITHUB_JOB"] || "";
  const analysis_key = await getAnalysisKey();
  let workflowStartedAt = process.env[sharedEnv.CODEQL_WORKFLOW_STARTED_AT];
  if (workflowStartedAt === undefined) {
    workflowStartedAt = actionStartedAt.toISOString();
    core.exportVariable(
      sharedEnv.CODEQL_WORKFLOW_STARTED_AT,
      workflowStartedAt
    );
  }
  const runnerOs = getRequiredEnvParam("RUNNER_OS");
  const codeQlCliVersion = getCachedCodeQlVersion();
  const actionRef = process.env["GITHUB_ACTION_REF"];
  const testingEnvironment =
    process.env[sharedEnv.CODEQL_ACTION_TESTING_ENVIRONMENT] || "";
  // re-export the testing environment variable so that it is available to subsequent steps,
  // even if it was only set for this step
  if (testingEnvironment !== "") {
    core.exportVariable(
      sharedEnv.CODEQL_ACTION_TESTING_ENVIRONMENT,
      testingEnvironment
    );
  }

  const statusReport: StatusReportBase = {
    workflow_run_id: workflowRunID,
    workflow_name: workflowName,
    job_name: jobName,
    analysis_key,
    commit_oid: commitOid,
    ref,
    action_name: actionName,
    action_ref: actionRef,
    action_oid: "unknown", // TODO decide if it's possible to fill this in
    started_at: workflowStartedAt,
    action_started_at: actionStartedAt.toISOString(),
    status,
    testing_environment: testingEnvironment,
    runner_os: runnerOs,
    action_version: pkg.version,
  };

  // Add optional parameters
  if (cause) {
    statusReport.cause = cause;
  }
  if (exception) {
    statusReport.exception = exception;
  }
  if (
    status === "success" ||
    status === "failure" ||
    status === "aborted" ||
    status === "user-error"
  ) {
    statusReport.completed_at = new Date().toISOString();
  }
  const matrix = getRequiredInput("matrix");
  if (matrix) {
    statusReport.matrix_vars = matrix;
  }
  if ("RUNNER_ARCH" in process.env) {
    // RUNNER_ARCH is available only in GHES 3.4 and later
    // Values other than X86, X64, ARM, or ARM64 are discarded server side
    statusReport.runner_arch = process.env["RUNNER_ARCH"];
  }
  if (runnerOs === "Windows" || runnerOs === "macOS") {
    statusReport.runner_os_release = os.release();
  }
  if (codeQlCliVersion !== undefined) {
    statusReport.codeql_version = codeQlCliVersion;
  }

  return statusReport;
}

const GENERIC_403_MSG =
  "The repo on which this action is running is not opted-in to CodeQL code scanning.";
const GENERIC_404_MSG =
  "Not authorized to use the CodeQL code scanning feature on this repo.";
const OUT_OF_DATE_MSG =
  "CodeQL Action is out-of-date. Please upgrade to the latest version of codeql-action.";
const INCOMPATIBLE_MSG =
  "CodeQL Action version is incompatible with the code scanning endpoint. Please update to a compatible version of codeql-action.";

/**
 * Send a status report to the code_scanning/analysis/status endpoint.
 *
 * Optionally checks the response from the API endpoint and sets the action
 * as failed if the status report failed. This is only expected to be used
 * when sending a 'starting' report.
 *
 * Returns whether sending the status report was successful of not.
 */
export async function sendStatusReport<S extends StatusReportBase>(
  statusReport: S
): Promise<boolean> {
  const statusReportJSON = JSON.stringify(statusReport);
  core.debug(`Sending status report: ${statusReportJSON}`);
  // If in test mode we don't want to upload the results
  if (isInTestMode()) {
    core.debug("In test mode. Status reports are not uploaded.");
    return true;
  }

  const nwo = getRequiredEnvParam("GITHUB_REPOSITORY");
  const [owner, repo] = nwo.split("/");
  const client = api.getApiClient();

  try {
    await client.request(
      "PUT /repos/:owner/:repo/code-scanning/analysis/status",
      {
        owner,
        repo,
        data: statusReportJSON,
      }
    );

    return true;
  } catch (e) {
    console.log(e);
    if (isHTTPError(e)) {
      switch (e.status) {
        case 403:
          if (workflowIsTriggeredByPushEvent() && isDependabotActor()) {
            core.setFailed(
              'Workflows triggered by Dependabot on the "push" event run with read-only access. ' +
                "Uploading Code Scanning results requires write access. " +
                'To use Code Scanning with Dependabot, please ensure you are using the "pull_request" event for this workflow and avoid triggering on the "push" event for Dependabot branches. ' +
                "See https://docs.github.com/en/code-security/secure-coding/configuring-code-scanning#scanning-on-push for more information on how to configure these events."
            );
          } else {
            core.setFailed(e.message || GENERIC_403_MSG);
          }
          return false;
        case 404:
          core.setFailed(GENERIC_404_MSG);
          return false;
        case 422:
          // schema incompatibility when reporting status
          // this means that this action version is no longer compatible with the API
          // we still want to continue as it is likely the analysis endpoint will work
          if (getRequiredEnvParam("GITHUB_SERVER_URL") !== GITHUB_DOTCOM_URL) {
            core.debug(INCOMPATIBLE_MSG);
          } else {
            core.debug(OUT_OF_DATE_MSG);
          }
          return true;
      }
    }

    // something else has gone wrong and the request/response will be logged by octokit
    // it's possible this is a transient error and we should continue scanning
    core.error(
      "An unexpected error occurred when sending code scanning status report."
    );
    return true;
  }
}

export function workflowEventName() {
  // If the original event is dynamic CODESCANNING_EVENT_NAME will contain the right info (push/pull_request)
  if (process.env["GITHUB_EVENT_NAME"] === "dynamic") {
    const value = process.env["CODESCANNING_EVENT_NAME"];
    if (value === undefined || value.length === 0) {
      return process.env["GITHUB_EVENT_NAME"];
    }
    return value;
  }
  return process.env["GITHUB_EVENT_NAME"];
}

// Was the workflow run triggered by a `push` event, for example as opposed to a `pull_request` event.
function workflowIsTriggeredByPushEvent() {
  return workflowEventName() === "push";
}

// Is dependabot the actor that triggered the current workflow run.
function isDependabotActor() {
  return process.env["GITHUB_ACTOR"] === "dependabot[bot]";
}

// Is the current action executing a local copy (i.e. we're running a workflow on the codeql-action repo itself)
// as opposed to running a remote action (i.e. when another repo references us)
export function isRunningLocalAction(): boolean {
  const relativeScriptPath = getRelativeScriptPath();
  return (
    relativeScriptPath.startsWith("..") || path.isAbsolute(relativeScriptPath)
  );
}

// Get the location where the action is running from.
// This can be used to get the actions name or tell if we're running a local action.
export function getRelativeScriptPath(): string {
  const runnerTemp = getRequiredEnvParam("RUNNER_TEMP");
  const actionsDirectory = path.join(path.dirname(runnerTemp), "_actions");
  return path.relative(actionsDirectory, __filename);
}

// Reads the contents of GITHUB_EVENT_PATH as a JSON object
function getWorkflowEvent(): any {
  const eventJsonFile = getRequiredEnvParam("GITHUB_EVENT_PATH");
  try {
    return JSON.parse(fs.readFileSync(eventJsonFile, "utf-8"));
  } catch (e) {
    throw new Error(
      `Unable to read workflow event JSON from ${eventJsonFile}: ${e}`
    );
  }
}

function removeRefsHeadsPrefix(ref: string): string {
  return ref.startsWith("refs/heads/") ? ref.slice("refs/heads/".length) : ref;
}

// Is the version of the repository we are currently analyzing from the default branch,
// or alternatively from another branch or a pull request.
export async function isAnalyzingDefaultBranch(): Promise<boolean> {
  // Get the current ref and trim and refs/heads/ prefix
  let currentRef = await getRef();
  currentRef = removeRefsHeadsPrefix(currentRef);

  const event = getWorkflowEvent();
  let defaultBranch = event?.repository?.default_branch;

  if (process.env.GITHUB_EVENT_NAME === "schedule") {
    defaultBranch = removeRefsHeadsPrefix(getRequiredEnvParam("GITHUB_REF"));
  }

  return currentRef === defaultBranch;
}

export async function printDebugLogs(config: Config) {
  for (const language of config.languages) {
    const databaseDirectory = getCodeQLDatabasePath(config, language);
    const logsDirectory = path.join(databaseDirectory, "log");
    if (!doesDirectoryExist(logsDirectory)) {
      core.info(`Directory ${logsDirectory} does not exist.`);
      continue; // Skip this language database.
    }

    const walkLogFiles = (dir: string) => {
      const entries = fs.readdirSync(dir, { withFileTypes: true });
      if (entries.length === 0) {
        core.info(`No debug logs found at directory ${logsDirectory}.`);
      }
      for (const entry of entries) {
        if (entry.isFile()) {
          const absolutePath = path.resolve(dir, entry.name);
          core.startGroup(
            `CodeQL Debug Logs - ${language} - ${entry.name} from file at path ${absolutePath}`
          );
          process.stdout.write(fs.readFileSync(absolutePath));
          core.endGroup();
        } else if (entry.isDirectory()) {
          walkLogFiles(path.resolve(dir, entry.name));
        }
      }
    };
    walkLogFiles(logsDirectory);
  }
}