import * as fs from "fs";
import * as path from "path";
import { performance } from "perf_hooks";

import { safeWhich } from "@chrisgavin/safe-which";
import del from "del";
import * as yaml from "js-yaml";

import * as actionsUtil from "./actions-util";
import { setupCppAutobuild } from "./autobuild";
import {
  CODEQL_VERSION_ANALYSIS_SUMMARY_V2,
  CodeQL,
  getCodeQL,
} from "./codeql";
import * as configUtils from "./config-utils";
import { addDiagnostic, makeDiagnostic } from "./diagnostics";
import { EnvVar } from "./environment";
import { FeatureEnablement, Feature } from "./feature-flags";
import { isScannedLanguage, Language } from "./languages";
import { Logger, withGroup } from "./logging";
import { DatabaseCreationTimings, EventReport } from "./status-report";
import { ToolsFeature } from "./tools-features";
import { endTracingForCluster } from "./tracer-config";
import { validateSarifFileSchema } from "./upload-lib";
import * as util from "./util";
import { BuildMode } from "./util";

export class CodeQLAnalysisError extends Error {
  constructor(
    public queriesStatusReport: QueriesStatusReport,
    public message: string,
    public error: Error,
  ) {
    super(message);
    this.name = "CodeQLAnalysisError";
  }
}

export interface QueriesStatusReport {
  /**
   * Time taken in ms to run queries for cpp (or undefined if this language was not analyzed).
   *
   * The "builtin" designation is now outdated with the move to CLI config parsing: this is the time
   * taken to run _all_ the queries.
   */
  analyze_builtin_queries_cpp_duration_ms?: number;
  /**
   * Time taken in ms to run queries for csharp (or undefined if this language was not analyzed).
   *
   * The "builtin" designation is now outdated with the move to CLI config parsing: this is the time
   * taken to run _all_ the queries.
   */
  analyze_builtin_queries_csharp_duration_ms?: number;
  /**
   * Time taken in ms to run queries for go (or undefined if this language was not analyzed).
   *
   * The "builtin" designation is now outdated with the move to CLI config parsing: this is the time
   * taken to run _all_ the queries.
   */
  analyze_builtin_queries_go_duration_ms?: number;
  /**
   * Time taken in ms to run queries for java (or undefined if this language was not analyzed).
   *
   * The "builtin" designation is now outdated with the move to CLI config parsing: this is the time
   * taken to run _all_ the queries.
   */
  analyze_builtin_queries_java_duration_ms?: number;
  /**
   * Time taken in ms to run queries for javascript (or undefined if this language was not analyzed).
   *
   * The "builtin" designation is now outdated with the move to CLI config parsing: this is the time
   * taken to run _all_ the queries.
   */
  analyze_builtin_queries_javascript_duration_ms?: number;
  /**
   * Time taken in ms to run queries for python (or undefined if this language was not analyzed).
   *
   * The "builtin" designation is now outdated with the move to CLI config parsing: this is the time
   * taken to run _all_ the queries.
   */
  analyze_builtin_queries_python_duration_ms?: number;
  /**
   * Time taken in ms to run queries for ruby (or undefined if this language was not analyzed).
   *
   * The "builtin" designation is now outdated with the move to CLI config parsing: this is the time
   * taken to run _all_ the queries.
   */
  analyze_builtin_queries_ruby_duration_ms?: number;
  /** Time taken in ms to run queries for swift (or undefined if this language was not analyzed).
   *
   * The "builtin" designation is now outdated with the move to CLI config parsing: this is the time
   * taken to run _all_ the queries.
   */
  analyze_builtin_queries_swift_duration_ms?: number;

  /** Time taken in ms to interpret results for cpp (or undefined if this language was not analyzed). */
  interpret_results_cpp_duration_ms?: number;
  /** Time taken in ms to interpret results for csharp (or undefined if this language was not analyzed). */
  interpret_results_csharp_duration_ms?: number;
  /** Time taken in ms to interpret results for go (or undefined if this language was not analyzed). */
  interpret_results_go_duration_ms?: number;
  /** Time taken in ms to interpret results for java (or undefined if this language was not analyzed). */
  interpret_results_java_duration_ms?: number;
  /** Time taken in ms to interpret results for javascript (or undefined if this language was not analyzed). */
  interpret_results_javascript_duration_ms?: number;
  /** Time taken in ms to interpret results for python (or undefined if this language was not analyzed). */
  interpret_results_python_duration_ms?: number;
  /** Time taken in ms to interpret results for ruby (or undefined if this language was not analyzed). */
  interpret_results_ruby_duration_ms?: number;
  /** Time taken in ms to interpret results for swift (or undefined if this language was not analyzed). */
  interpret_results_swift_duration_ms?: number;

  /** Name of language that errored during analysis (or undefined if no language failed). */
  analyze_failure_language?: string;
  /** Reports on discrete events associated with this status report. */
  event_reports?: EventReport[];
}

async function setupPythonExtractor(logger: Logger) {
  const codeqlPython = process.env["CODEQL_PYTHON"];
  if (codeqlPython === undefined || codeqlPython.length === 0) {
    // If CODEQL_PYTHON is not set, no dependencies were installed, so we don't need to do anything
    return;
  }

  logger.warning(
    "The CODEQL_PYTHON environment variable is no longer supported. Please remove it from your workflow. This environment variable was originally used to specify a Python executable that included the dependencies of your Python code, however Python analysis no longer uses these dependencies." +
      "\nIf you used CODEQL_PYTHON to force the version of Python to analyze as, please use CODEQL_EXTRACTOR_PYTHON_ANALYSIS_VERSION instead, such as 'CODEQL_EXTRACTOR_PYTHON_ANALYSIS_VERSION=2.7' or 'CODEQL_EXTRACTOR_PYTHON_ANALYSIS_VERSION=3.11'.",
  );
  return;
}

export async function runExtraction(
  codeql: CodeQL,
  config: configUtils.Config,
  logger: Logger,
) {
  for (const language of config.languages) {
    if (dbIsFinalized(config, language, logger)) {
      logger.debug(
        `Database for ${language} has already been finalized, skipping extraction.`,
      );
      continue;
    }

    if (shouldExtractLanguage(config, language)) {
      logger.startGroup(`Extracting ${language}`);
      if (language === Language.python) {
        await setupPythonExtractor(logger);
      }
      if (
        config.buildMode &&
        (await codeql.supportsFeature(ToolsFeature.TraceCommandUseBuildMode))
      ) {
        if (
          language === Language.cpp &&
          config.buildMode === BuildMode.Autobuild
        ) {
          await setupCppAutobuild(codeql, logger);
        }
        await codeql.extractUsingBuildMode(config, language);
      } else {
        await codeql.extractScannedLanguage(config, language);
      }
      logger.endGroup();
    }
  }
}

function shouldExtractLanguage(
  config: configUtils.Config,
  language: Language,
): boolean {
  return (
    config.buildMode === BuildMode.None ||
    (config.buildMode === BuildMode.Autobuild &&
      process.env[EnvVar.AUTOBUILD_DID_COMPLETE_SUCCESSFULLY] !== "true") ||
    (!config.buildMode && isScannedLanguage(language))
  );
}

export function dbIsFinalized(
  config: configUtils.Config,
  language: Language,
  logger: Logger,
) {
  const dbPath = util.getCodeQLDatabasePath(config, language);
  try {
    const dbInfo = yaml.load(
      fs.readFileSync(path.resolve(dbPath, "codeql-database.yml"), "utf8"),
    ) as { inProgress?: boolean };
    return !("inProgress" in dbInfo);
  } catch {
    logger.warning(
      `Could not check whether database for ${language} was finalized. Assuming it is not.`,
    );
    return false;
  }
}

async function finalizeDatabaseCreation(
  codeql: CodeQL,
  config: configUtils.Config,
  threadsFlag: string,
  memoryFlag: string,
  logger: Logger,
): Promise<DatabaseCreationTimings> {
  const extractionStart = performance.now();
  await runExtraction(codeql, config, logger);
  const extractionTime = performance.now() - extractionStart;

  const trapImportStart = performance.now();
  for (const language of config.languages) {
    if (dbIsFinalized(config, language, logger)) {
      logger.info(
        `There is already a finalized database for ${language} at the location where the CodeQL Action places databases, so we did not create one.`,
      );
    } else {
      logger.startGroup(`Finalizing ${language}`);
      await codeql.finalizeDatabase(
        util.getCodeQLDatabasePath(config, language),
        threadsFlag,
        memoryFlag,
        config.debugMode,
      );
      logger.endGroup();
    }
  }
  const trapImportTime = performance.now() - trapImportStart;

  return {
    scanned_language_extraction_duration_ms: Math.round(extractionTime),
    trap_import_duration_ms: Math.round(trapImportTime),
  };
}

/**
 * Set up the diff-informed analysis feature.
 *
 * @param baseRef The base branch name, used for calculating the diff range.
 * @param headRef The head branch name, used for calculating the diff range.
 * @param codeql
 * @param logger
 * @param features
 * @returns Absolute path to the directory containing the extension pack for
 * the diff range information, or `undefined` if the feature is disabled.
 */
export async function setupDiffInformedQueryRun(
  baseRef: string,
  headRef: string,
  codeql: CodeQL,
  logger: Logger,
  features: FeatureEnablement,
): Promise<string | undefined> {
  if (!(await features.getValue(Feature.DiffInformedQueries, codeql))) {
    return undefined;
  }
  return await withGroup("Generating diff range extension pack", async () => {
    const diffRanges = await getPullRequestEditedDiffRanges(
      baseRef,
      headRef,
      logger,
    );
    return writeDiffRangeDataExtensionPack(logger, diffRanges);
  });
}

interface DiffThunkRange {
  path: string;
  startLine: number;
  endLine: number;
}

/**
 * Return the file line ranges that were added or modified in the pull request.
 *
 * @param baseRef The base branch name, used for calculating the diff range.
 * @param headRef The head branch name, used for calculating the diff range.
 * @param logger
 * @returns An array of tuples, where each tuple contains the absolute path of a
 * file, the start line and the end line (both 1-based and inclusive) of an
 * added or modified range in that file. Returns `undefined` if the action was
 * not triggered by a pull request or if there was an error.
 */
async function getPullRequestEditedDiffRanges(
  baseRef: string,
  headRef: string,
  logger: Logger,
): Promise<DiffThunkRange[] | undefined> {
  const checkoutPath = actionsUtil.getOptionalInput("checkout_path");
  if (checkoutPath === undefined) {
    return undefined;
  }

  // To compute the merge bases between the base branch and the PR topic branch,
  // we need to fetch the commit graph from the branch heads to those merge
  // babes. The following 4-step procedure does so while limiting the amount of
  // history fetched.

  // Step 1: Deepen from the PR merge commit to the base branch head and the PR
  // topic branch head, so that the PR merge commit is no longer considered a
  // grafted commit.
  await actionsUtil.deepenGitHistory();
  // Step 2: Fetch the base branch shallow history. This step ensures that the
  // base branch name is present in the local repository. Normally the base
  // branch name would be added by Step 4. However, if the base branch head is
  // an ancestor of the PR topic branch head, Step 4 would fail without doing
  // anything, so we need to fetch the base branch explicitly.
  await actionsUtil.gitFetch(baseRef, ["--depth=1"]);
  // Step 3: Fetch the PR topic branch history, stopping when we reach commits
  // that are reachable from the base branch head.
  await actionsUtil.gitFetch(headRef, [`--shallow-exclude=${baseRef}`]);
  // Step 4: Fetch the base branch history, stopping when we reach commits that
  // are reachable from the PR topic branch head.
  await actionsUtil.gitFetch(baseRef, [`--shallow-exclude=${headRef}`]);
  // Step 5: Deepen the history so that we have the merge bases between the base
  // branch and the PR topic branch.
  await actionsUtil.deepenGitHistory();

  // To compute the exact same diff as GitHub would compute for the PR, we need
  // to use the same merge base as GitHub. That is easy to do if there is only
  // one merge base, which is by far the most common case. If there are multiple
  // merge bases, we stop without producing a diff range.
  const mergeBases = await actionsUtil.getAllGitMergeBases([baseRef, headRef]);
  logger.info(`Merge bases: ${mergeBases.join(", ")}`);
  if (mergeBases.length !== 1) {
    logger.info(
      "Cannot compute diff range because baseRef and headRef " +
        `have ${mergeBases.length} merge bases (instead of exactly 1).`,
    );
    return undefined;
  }

  const diffHunkHeaders = await actionsUtil.getGitDiffHunkHeaders(
    mergeBases[0],
    headRef,
  );
  if (diffHunkHeaders === undefined) {
    return undefined;
  }

  const results = new Array<DiffThunkRange>();

  let changedFile = "";
  for (const line of diffHunkHeaders) {
    if (line.startsWith("+++ ")) {
      const filePath = actionsUtil.decodeGitFilePath(line.substring(4));
      if (filePath.startsWith("b/")) {
        // The file was edited: track all hunks in the file
        changedFile = filePath.substring(2);
      } else if (filePath === "/dev/null") {
        // The file was deleted: skip all hunks in the file
        changedFile = "";
      } else {
        logger.warning(`Failed to parse diff hunk header line: ${line}`);
        return undefined;
      }
      continue;
    }
    if (line.startsWith("@@ ")) {
      if (changedFile === "") continue;

      const match = line.match(/^@@ -\d+(?:,\d+)? \+(\d+)(?:,(\d+))? @@/);
      if (match === null) {
        logger.warning(`Failed to parse diff hunk header line: ${line}`);
        return undefined;
      }
      const startLine = parseInt(match[1], 10);
      const numLines = parseInt(match[2], 10);
      if (numLines === 0) {
        // The hunk was a deletion: skip it
        continue;
      }
      const endLine = startLine + (numLines || 1) - 1;
      results.push({
        path: path.join(checkoutPath, changedFile),
        startLine,
        endLine,
      });
    }
  }
  return results;
}

/**
 * Create an extension pack in the temporary directory that contains the file
 * line ranges that were added or modified in the pull request.
 *
 * @param logger
 * @param ranges The file line ranges, as returned by
 * `getPullRequestEditedDiffRanges`.
 * @returns The absolute path of the directory containing the extension pack, or
 * `undefined` if no extension pack was created.
 */
function writeDiffRangeDataExtensionPack(
  logger: Logger,
  ranges: DiffThunkRange[] | undefined,
): string | undefined {
  if (ranges === undefined) {
    return undefined;
  }

  const diffRangeDir = path.join(
    actionsUtil.getTemporaryDirectory(),
    "pr-diff-range",
  );
  fs.mkdirSync(diffRangeDir);
  fs.writeFileSync(
    path.join(diffRangeDir, "qlpack.yml"),
    `
name: codeql-action/pr-diff-range
version: 0.0.0
library: true
extensionTargets:
  codeql/util: '*'
dataExtensions:
  - pr-diff-range.yml
`,
  );

  const header = `
extensions:
  - addsTo:
      pack: codeql/util
      extensible: restrictAlertsTo
    data:
`;

  let data = ranges
    .map((range) => `      - ["${range[0]}", ${range[1]}, ${range[2]}]\n`)
    .join("");
  if (!data) {
    // Ensure that the data extension is not empty, so that a pull request with
    // no edited lines would exclude (instead of accepting) all alerts.
    data = '      - ["", 0, 0]\n';
  }

  const extensionContents = header + data;
  const extensionFilePath = path.join(diffRangeDir, "pr-diff-range.yml");
  fs.writeFileSync(extensionFilePath, extensionContents);
  logger.debug(
    `Wrote pr-diff-range extension pack to ${extensionFilePath}:\n${extensionContents}`,
  );

  return diffRangeDir;
}

// Runs queries and creates sarif files in the given folder
export async function runQueries(
  sarifFolder: string,
  memoryFlag: string,
  addSnippetsFlag: string,
  threadsFlag: string,
  diffRangePackDir: string | undefined,
  automationDetailsId: string | undefined,
  config: configUtils.Config,
  logger: Logger,
  features: FeatureEnablement,
): Promise<QueriesStatusReport> {
  const statusReport: QueriesStatusReport = {};

  const dataExtensionFlags = diffRangePackDir
    ? [
        `--additional-packs=${diffRangePackDir}`,
        "--extension-packs=codeql-action/pr-diff-range",
      ]
    : [];
  const sarifRunPropertyFlag = diffRangePackDir
    ? "--sarif-run-property=incrementalMode=diff-informed"
    : undefined;

  const codeql = await getCodeQL(config.codeQLCmd);
  const queryFlags = [memoryFlag, threadsFlag, ...dataExtensionFlags];

  for (const language of config.languages) {
    try {
      const sarifFile = path.join(sarifFolder, `${language}.sarif`);

      // The work needed to generate the query suites
      // is done in the CLI. We just need to make a single
      // call to run all the queries for each language and
      // another to interpret the results.
      logger.startGroup(`Running queries for ${language}`);
      const startTimeRunQueries = new Date().getTime();
      const databasePath = util.getCodeQLDatabasePath(config, language);
      await codeql.databaseRunQueries(databasePath, queryFlags);
      logger.debug(`Finished running queries for ${language}.`);
      // TODO should not be using `builtin` here. We should be using `all` instead.
      // The status report does not support `all` yet.
      statusReport[`analyze_builtin_queries_${language}_duration_ms`] =
        new Date().getTime() - startTimeRunQueries;

      logger.startGroup(`Interpreting results for ${language}`);
      const startTimeInterpretResults = new Date();
      const analysisSummary = await runInterpretResults(
        language,
        undefined,
        sarifFile,
        config.debugMode,
      );
      const endTimeInterpretResults = new Date();
      statusReport[`interpret_results_${language}_duration_ms`] =
        endTimeInterpretResults.getTime() - startTimeInterpretResults.getTime();
      logger.endGroup();
      logger.info(analysisSummary);

      if (await features.getValue(Feature.QaTelemetryEnabled)) {
        const perQueryAlertCounts = getPerQueryAlertCounts(sarifFile, logger);

        const perQueryAlertCountEventReport: EventReport = {
          event: "codeql database interpret-results",
          started_at: startTimeInterpretResults.toISOString(),
          completed_at: endTimeInterpretResults.toISOString(),
          exit_status: "success",
          language,
          properties: {
            alertCounts: perQueryAlertCounts,
          },
        };

        if (statusReport["event_reports"] === undefined) {
          statusReport["event_reports"] = [];
        }
        statusReport["event_reports"].push(perQueryAlertCountEventReport);
      }

      if (
        !(await util.codeQlVersionAtLeast(
          codeql,
          CODEQL_VERSION_ANALYSIS_SUMMARY_V2,
        ))
      ) {
        await runPrintLinesOfCode(language);
      }
    } catch (e) {
      statusReport.analyze_failure_language = language;
      throw new CodeQLAnalysisError(
        statusReport,
        `Error running analysis for ${language}: ${util.getErrorMessage(e)}`,
        util.wrapError(e),
      );
    }
  }

  return statusReport;

  async function runInterpretResults(
    language: Language,
    queries: string[] | undefined,
    sarifFile: string,
    enableDebugLogging: boolean,
  ): Promise<string> {
    const databasePath = util.getCodeQLDatabasePath(config, language);
    return await codeql.databaseInterpretResults(
      databasePath,
      queries,
      sarifFile,
      addSnippetsFlag,
      threadsFlag,
      enableDebugLogging ? "-vv" : "-v",
      sarifRunPropertyFlag,
      automationDetailsId,
      config,
      features,
    );
  }

  /** Get an object with all queries and their counts parsed from a SARIF file path. */
  function getPerQueryAlertCounts(
    sarifPath: string,
    log: Logger,
  ): Record<string, number> {
    validateSarifFileSchema(sarifPath, log);
    const sarifObject = JSON.parse(
      fs.readFileSync(sarifPath, "utf8"),
    ) as util.SarifFile;
    // We do not need to compute fingerprints because we are not sending data based off of locations.

    // Generate the query: alert count object
    const perQueryAlertCounts: Record<string, number> = {};

    // All rules (queries), from all results, from all runs
    for (const sarifRun of sarifObject.runs) {
      if (sarifRun.results) {
        for (const result of sarifRun.results) {
          const query = result.rule?.id || result.ruleId;
          if (query) {
            perQueryAlertCounts[query] = (perQueryAlertCounts[query] || 0) + 1;
          }
        }
      }
    }
    return perQueryAlertCounts;
  }

  async function runPrintLinesOfCode(language: Language): Promise<string> {
    const databasePath = util.getCodeQLDatabasePath(config, language);
    return await codeql.databasePrintBaseline(databasePath);
  }
}

export async function runFinalize(
  outputDir: string,
  threadsFlag: string,
  memoryFlag: string,
  codeql: CodeQL,
  config: configUtils.Config,
  logger: Logger,
): Promise<DatabaseCreationTimings> {
  try {
    await del(outputDir, { force: true });
  } catch (error: any) {
    if (error?.code !== "ENOENT") {
      throw error;
    }
  }
  await fs.promises.mkdir(outputDir, { recursive: true });

  const timings = await finalizeDatabaseCreation(
    codeql,
    config,
    threadsFlag,
    memoryFlag,
    logger,
  );

  // If we didn't already end tracing in the autobuild Action, end it now.
  if (process.env[EnvVar.AUTOBUILD_DID_COMPLETE_SUCCESSFULLY] !== "true") {
    await endTracingForCluster(codeql, config, logger);
  }
  return timings;
}

export async function warnIfGoInstalledAfterInit(
  config: configUtils.Config,
  logger: Logger,
) {
  // Check that `which go` still points at the same path it did when the `init` Action ran to ensure that no steps
  // in-between performed any setup. We encourage users to perform all setup tasks before initializing CodeQL so that
  // the setup tasks do not interfere with our analysis.
  // Furthermore, if we installed a wrapper script in the `init` Action, we need to ensure that there isn't a step
  // in the workflow after the `init` step which installs a different version of Go and takes precedence in the PATH,
  // thus potentially circumventing our workaround that allows tracing to work.
  const goInitPath = process.env[EnvVar.GO_BINARY_LOCATION];

  if (
    process.env[EnvVar.DID_AUTOBUILD_GOLANG] !== "true" &&
    goInitPath !== undefined
  ) {
    const goBinaryPath = await safeWhich("go");

    if (goInitPath !== goBinaryPath) {
      logger.warning(
        `Expected \`which go\` to return ${goInitPath}, but got ${goBinaryPath}: please ensure that the correct version of Go is installed before the \`codeql-action/init\` Action is used.`,
      );

      addDiagnostic(
        config,
        Language.go,
        makeDiagnostic(
          "go/workflow/go-installed-after-codeql-init",
          "Go was installed after the `codeql-action/init` Action was run",
          {
            markdownMessage:
              "To avoid interfering with the CodeQL analysis, perform all installation steps before calling the `github/codeql-action/init` Action.",
            visibility: {
              statusPage: true,
              telemetry: true,
              cliSummaryTable: true,
            },
            severity: "warning",
          },
        ),
      );
    }
  }
}

export async function runCleanup(
  config: configUtils.Config,
  cleanupLevel: string,
  logger: Logger,
): Promise<void> {
  logger.startGroup("Cleaning up databases");
  for (const language of config.languages) {
    const codeql = await getCodeQL(config.codeQLCmd);
    const databasePath = util.getCodeQLDatabasePath(config, language);
    await codeql.databaseCleanup(databasePath, cleanupLevel);
  }
  logger.endGroup();
}