import { SkipTestCase, UnexpectedPassError } from '../../framework/fixture.js';
import { globalTestConfig } from '../../framework/test_config.js';
import { now, assert } from '../../util/util.js';

import { LogMessageWithStack } from './log_message.js';
import { Expectation, LiveTestCaseResult, Status } from './result.js';

enum LogSeverity {
  NotRun = 0,
  Skip = 1,
  Pass = 2,
  Warn = 3,
  ExpectFailed = 4,
  ValidationFailed = 5,
  ThrewException = 6,
}

const kMaxLogStacks = 2;
const kMinSeverityForStack = LogSeverity.Warn;

function logSeverityToString(status: LogSeverity): Status {
  switch (status) {
    case LogSeverity.NotRun:
      return 'notrun';
    case LogSeverity.Pass:
      return 'pass';
    case LogSeverity.Skip:
      return 'skip';
    case LogSeverity.Warn:
      return 'warn';
    default:
      return 'fail'; // Everything else is an error
  }
}

/** Holds onto a LiveTestCaseResult owned by the Logger, and writes the results into it. */
export class TestCaseRecorder {
  readonly result: LiveTestCaseResult;
  public nonskippedSubcaseCount: number = 0;
  private inSubCase: boolean = false;
  private subCaseStatus = LogSeverity.NotRun;
  private finalCaseStatus = LogSeverity.NotRun;
  private hideStacksBelowSeverity = kMinSeverityForStack;
  private startTime = -1;
  private logs: LogMessageWithStack[] = [];
  private logLinesAtCurrentSeverity = 0;
  private debugging = false;
  /** Used to dedup log messages which have identical stacks. */
  private messagesForPreviouslySeenStacks = new Map<string, LogMessageWithStack>();

  constructor(result: LiveTestCaseResult, debugging: boolean) {
    this.result = result;
    this.debugging = debugging;
  }

  start(): void {
    assert(this.startTime < 0, 'TestCaseRecorder cannot be reused');
    this.startTime = now();
  }

  finish(): void {
    // This is a framework error. If this assert is hit, it won't be localized
    // to a test. The whole test run will fail out.
    assert(this.startTime >= 0, 'internal error: finish() before start()');

    const timeMilliseconds = now() - this.startTime;
    // Round to next microsecond to avoid storing useless .xxxx00000000000002 in results.
    this.result.timems = Math.ceil(timeMilliseconds * 1000) / 1000;

    if (this.finalCaseStatus === LogSeverity.Skip && this.nonskippedSubcaseCount !== 0) {
      this.threw(new Error('internal error: case is "skip" but has nonskipped subcases'));
    }

    // Convert numeric enum back to string (but expose 'exception' as 'fail')
    this.result.status = logSeverityToString(this.finalCaseStatus);

    this.result.logs = this.logs;
  }

  beginSubCase() {
    this.subCaseStatus = LogSeverity.NotRun;
    this.inSubCase = true;
  }

  endSubCase(expectedStatus: Expectation) {
    if (this.subCaseStatus !== LogSeverity.Skip) {
      this.nonskippedSubcaseCount++;
    }
    try {
      if (expectedStatus === 'fail') {
        if (this.subCaseStatus <= LogSeverity.Warn) {
          throw new UnexpectedPassError();
        } else {
          this.subCaseStatus = LogSeverity.Pass;
        }
      }
    } finally {
      this.inSubCase = false;
      this.finalCaseStatus = Math.max(this.finalCaseStatus, this.subCaseStatus);
    }
  }

  injectResult(injectedResult: LiveTestCaseResult): void {
    Object.assign(this.result, injectedResult);
  }

  debug(ex: Error): void {
    if (!this.debugging) return;
    this.logImpl(LogSeverity.Pass, 'DEBUG', ex);
  }

  info(ex: Error): void {
    // We need this to use the lowest LogSeverity so it doesn't override the current severity for this test case.
    this.logImpl(LogSeverity.NotRun, 'INFO', ex);
  }

  skipped(ex: SkipTestCase): void {
    this.logImpl(LogSeverity.Skip, 'SKIP', ex);
  }

  warn(ex: Error): void {
    this.logImpl(LogSeverity.Warn, 'WARN', ex);
  }

  expectationFailed(ex: Error): void {
    this.logImpl(LogSeverity.ExpectFailed, 'EXPECTATION FAILED', ex);
  }

  validationFailed(ex: Error): void {
    this.logImpl(LogSeverity.ValidationFailed, 'VALIDATION FAILED', ex);
  }

  passed(): void {
    if (this.inSubCase) {
      this.subCaseStatus = Math.max(this.subCaseStatus, LogSeverity.Pass);
    } else {
      this.finalCaseStatus = Math.max(this.finalCaseStatus, LogSeverity.Pass);
    }
  }

  threw(ex: unknown): void {
    if (ex instanceof SkipTestCase) {
      this.skipped(ex);
      return;
    }
    this.logImpl(LogSeverity.ThrewException, 'EXCEPTION', ex);
  }

  private logImpl(level: LogSeverity, name: string, baseException: unknown): void {
    assert(baseException instanceof Error, 'test threw a non-Error object');
    globalTestConfig.testHeartbeatCallback();
    const logMessage = new LogMessageWithStack(name, baseException);

    // Final case status should be the "worst" of all log entries.
    if (this.inSubCase) {
      this.subCaseStatus = Math.max(this.subCaseStatus, level);
    } else {
      this.finalCaseStatus = Math.max(this.finalCaseStatus, level);
    }

    // setFirstLineOnly for all logs except `kMaxLogStacks` stacks at the highest severity
    if (level > this.hideStacksBelowSeverity) {
      this.logLinesAtCurrentSeverity = 0;
      this.hideStacksBelowSeverity = level;

      // Go back and setFirstLineOnly for everything of a lower log level
      for (const log of this.logs) {
        log.setStackHidden('below max severity');
      }
    }
    if (level === this.hideStacksBelowSeverity) {
      this.logLinesAtCurrentSeverity++;
    } else if (level < kMinSeverityForStack) {
      logMessage.setStackHidden('');
    } else if (level < this.hideStacksBelowSeverity) {
      logMessage.setStackHidden('below max severity');
    }
    if (this.logLinesAtCurrentSeverity > kMaxLogStacks) {
      logMessage.setStackHidden(`only ${kMaxLogStacks} shown`);
    }

    this.logs.push(logMessage);
  }
}