/**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */;
open Common.Option.Infix;
open TestResult;
open TestResult.AggregatedResult;
open Time;

type terminalPrinter = {
  printString: string => unit,
  printEndline: string => unit,
  printNewline: unit => unit,
  flush: out_channel => unit,
};

let indent = (~indent: string, s: string): string => {
  let lines = Str.split(Str.regexp("\n"), s);
  let lines = List.map(line => indent ++ line, lines);
  String.concat("\n", lines);
};

let failFormatter = s => Pastel.red(s);
let messageIndent = "    ";
let stackIndent = "      ";
let titleIndent = "  ";
let passDisplay = () =>
  <Pastel color=Green inverse=true bold=true> " PASS " </Pastel>;
let failDisplay = () =>
  <Pastel color=Red inverse=true bold=true> " FAIL " </Pastel>;
let runningDisplay = () =>
  <Pastel color=Yellow inverse=true bold=true> " RUNS " </Pastel>;

module FCP =
  FileContextPrinter.Make({
    let config =
      FileContextPrinter.Config.initialize({linesBefore: 3, linesAfter: 3});
  });

let getStackInfo = (optLoc: option(Printexc.location), trace: string) => {
  let stackInfo =
    optLoc
    >>= (
      (l: Printexc.location) =>
        FCP.printFile(
          l.filename,
          (
            /* File-context-printer expects line number and column number
             * to both be 1-indexed, however the locations from Printexc
             * have 1 indexed lines and 0 indexed columns*/
            (l.line_number, l.start_char + 1),
            (l.line_number, l.end_char + 1),
          ),
        )
    )
    >>| (
      context =>
        String.concat(
          "\n\n",
          [
            indent(context, ~indent=stackIndent),
            indent(trace, ~indent=stackIndent),
          ],
        )
    );
  stackInfo;
};

let titleBullet = "• ";

let gatherFormattedFailureOutput = (testResults: list(testResult)) =>
  testResults
  |> List.fold_left(
       (acc, r) =>
         switch (r) {
         | {testStatus: Skipped(_), _}
         | {testStatus: Passed(_), _} => acc
         | {testStatus: Failed(message, loc, stack), fullName, _} =>
           let titleBullet = "• ";
           let title =
             Pastel.bold(
               failFormatter(titleIndent ++ titleBullet ++ fullName),
             );
           let indentedMessage = indent(message, ~indent=messageIndent);
           let parts =
             switch (getStackInfo(loc, stack)) {
             | Some(trace) => [title, indentedMessage, trace]
             | None => [title, indentedMessage]
             };
           let formattedOutput = String.concat("\n\n", parts);
           acc @ [formattedOutput];
         | {testStatus: Exception(e, loc, stack), fullName, _} =>
           let titleBullet = "• ";
           let title =
             Pastel.bold(
               failFormatter(titleIndent ++ titleBullet ++ fullName),
             );
           let exceptionMessage =
             indent(
               "Exception " ++ Pastel.dim(Printexc.to_string(e)),
               ~indent=messageIndent,
             );
           let parts =
             switch (getStackInfo(loc, stack)) {
             | Some(trace) => [title, exceptionMessage, trace]
             | None => [title, exceptionMessage]
             };
           let formattedOutput = String.concat("\n\n", parts);
           acc @ [formattedOutput];
         },
       [],
     );

let createRunSummary = (result: AggregatedResult.t) => {
  let testSuitePassFormatter =
    result.numPassedTestSuites > 0 ?
      s => <Pastel color=Green bold=true> s </Pastel> : (s => s);
  let testSuiteSkipFormatter =
    result.numPassedTestSuites > 0 ?
      s => <Pastel color=Yellow bold=true> s </Pastel> : (s => s);
  let testSuiteFailFormatter =
    result.numFailedTestSuites > 0 ?
      s => <Pastel color=Red bold=true> s </Pastel> : (s => s);
  let testPassFormatter =
    result.numPassedTests > 0 ?
      s => <Pastel color=Green bold=true> s </Pastel> : (s => s);
  let testSkipFormatter =
    result.numPassedTests > 0 ?
      s => <Pastel color=Yellow bold=true> s </Pastel> : (s => s);
  let testFailFormatter =
    result.numFailedTests > 0 ?
      s => <Pastel color=Red bold=true> s </Pastel> : (s => s);
  let testSuiteSummaryParts =
    [
      Some(
        testSuiteFailFormatter(
          string_of_int(result.numFailedTestSuites) ++ " failed",
        ),
      ),
      result.numSkippedTestSuites == 0 ?
        None :
        Some(
          testSuiteSkipFormatter(
            string_of_int(result.numSkippedTestSuites) ++ " skipped",
          ),
        ),
      Some(
        testSuitePassFormatter(
          string_of_int(result.numPassedTestSuites) ++ " passed",
        ),
      ),
      Some(string_of_int(result.numTotalTestSuites) ++ " total"),
    ]
    |> List.fold_left(
         (acc, part) =>
           switch (part) {
           | Some(part) => acc @ [part]
           | None => acc
           },
         [],
       );
  let testSuiteSummary =
    String.concat(
      "",
      [
        <Pastel bold=true color=WhiteBright> "Test Suites: " </Pastel>,
        String.concat(", ", testSuiteSummaryParts),
      ],
    );
  let testSummaryParts =
    [
      Some(
        testFailFormatter(string_of_int(result.numFailedTests) ++ " failed"),
      ),
      result.numSkippedTests == 0 ?
        None :
        Some(
          testSkipFormatter(
            string_of_int(result.numSkippedTests) ++ " skipped",
          ),
        ),
      Some(
        testPassFormatter(string_of_int(result.numPassedTests) ++ " passed"),
      ),
      Some(string_of_int(result.numTotalTests) ++ " total"),
    ]
    |> List.fold_left(
         (acc, part) =>
           switch (part) {
           | Some(part) => acc @ [part]
           | None => acc
           },
         [],
       );
  let testSummary =
    String.concat(
      "",
      [
        <Pastel bold=true color=WhiteBright> "Tests:       " </Pastel>,
        String.concat(", ", testSummaryParts),
      ],
    );
  let Seconds(duration) = Time.subtract(Clock.getTime(), result.startTime);
  let timeString =
    duration *. 1000. > 1. ? Printf.sprintf("%.3fs", duration) : "< 1ms";
  let timeSummary =
    String.concat(
      "",
      [
        <Pastel bold=true color=WhiteBright> "Time:        " </Pastel>,
        timeString,
      ],
    );

  String.concat("\n", [testSuiteSummary, testSummary, timeSummary]);
};

let printSnapshotStatus = testResult =>
  testResult.snapshotSummary
  >>= (
    snapshotSummary => {
      let {numCreatedSnapshots, numRemovedSnapshots, numUpdatedSnapshots} = snapshotSummary;
      let messages: ref(list(string)) = ref([]);
      if (numCreatedSnapshots > 0) {
        messages :=
          messages^
          @ [
            Pastel.yellow(
              String.concat(
                "",
                [
                  "Created ",
                  string_of_int(numCreatedSnapshots),
                  " missing snapshots",
                ],
              ),
            ),
          ];
      };

      if (numUpdatedSnapshots > 0) {
        messages :=
          messages^
          @ [
            Pastel.yellow(
              String.concat(
                "",
                [
                  "Updated ",
                  string_of_int(numUpdatedSnapshots),
                  " snapshots",
                ],
              ),
            ),
          ];
      };

      if (numRemovedSnapshots > 0) {
        messages :=
          messages^
          @ [
            Pastel.yellow(
              String.concat(
                "",
                [
                  "Removed ",
                  string_of_int(numRemovedSnapshots),
                  " unused snapshots",
                ],
              ),
            ),
          ];
      };
      if (List.length(messages^) > 0) {
        Some(String.concat("\n", messages^));
      } else {
        None;
      };
    }
  );

let createTerminalReporter = (printer: terminalPrinter): Reporter.t => {
  let runningDisplayLength = ref(0);
  {
    onTestSuiteStart: (testSuite: Reporter.testSuite) =>
      if (Pastel.getMode() == Terminal) {
        let update =
          String.concat(
            " ",
            [
              runningDisplay(),
              <Pastel color=WhiteBright> {testSuite.name} </Pastel>,
            ],
          );
        runningDisplayLength := String.length(update);
        printer.printString("\r" ++ update);
        printer.flush(stdout);
        ();
      },
    onTestSuiteResult: (aggregatedResult, testSuite, testSuiteResult) => {
      if (Pastel.getMode() == Terminal) {
        printer.printString(
          "\027[" ++ string_of_int(runningDisplayLength^) ++ "D\027[K",
        );
      };
      switch (testSuiteResult) {
      | {numFailedTests: 0, numPassedTests: 0, numSkippedTests} => ()
      | {numFailedTests: 0, numPassedTests: n, testResults: _, displayName} =>
        printer.printEndline(
          String.concat(
            " ",
            [passDisplay(), <Pastel color=WhiteBright> displayName </Pastel>],
          ),
        )
      | {numFailedTests: n, numPassedTests, testResults, displayName}
          when n > 0 =>
        printer.printEndline(
          String.concat(
            " ",
            [failDisplay(), <Pastel color=WhiteBright> displayName </Pastel>],
          ),
        );
        printer.printEndline(
          String.concat("\n\n", gatherFormattedFailureOutput(testResults)),
        );
        printer.printEndline("");
      | _ => raise(Invalid_argument("todo handle"))
      };
    },
    onRunStart: runStartInfo => {
      let numTestSuites = List.length(runStartInfo.testSuites);
      printer.printEndline(
        "Running "
        ++ string_of_int(numTestSuites)
        ++ (numTestSuites == 1 ? " test suite" : " test suites"),
      );
    },
    onRunComplete: aggregatedResult => {
      printer.printEndline(
        "\n" ++ createRunSummary(aggregatedResult) ++ "\n",
      );
      let _ = aggregatedResult |> printSnapshotStatus >>| printer.printEndline;
      ();
    },
  };
};