// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.

// These utilities are used by compiler.ts to format TypeScript diagnostics
// into Deno Diagnostics.

import {
  Diagnostic,
  DiagnosticCategory,
  DiagnosticMessageChain,
  DiagnosticItem,
} from "./diagnostics.ts";

const unstableDenoGlobalProperties = [
  "umask",
  "linkSync",
  "link",
  "symlinkSync",
  "symlink",
  "DirKind",
  "dir",
  "loadavg",
  "osRelease",
  "openPlugin",
  "DiagnosticCategory",
  "DiagnosticMessageChain",
  "DiagnosticItem",
  "Diagnostic",
  "formatDiagnostics",
  "CompilerOptions",
  "TranspileOnlyResult",
  "transpileOnly",
  "compile",
  "bundle",
  "Location",
  "applySourceMap",
  "LinuxSignal",
  "MacOSSignal",
  "Signal",
  "SignalStream",
  "signal",
  "signals",
  "setRaw",
  "utimeSync",
  "utime",
  "ShutdownMode",
  "shutdown",
  "DatagramConn",
  "UnixListenOptions",
  "listen",
  "listenDatagram",
  "UnixConnectOptions",
  "connect",
  "StartTlsOptions",
  "startTls",
  "kill",
  "PermissionName",
  "PermissionState",
  "RunPermissionDescriptor",
  "ReadPermissionDescriptor",
  "WritePermissionDescriptor",
  "NetPermissionDescriptor",
  "EnvPermissionDescriptor",
  "PluginPermissionDescriptor",
  "HrtimePermissionDescriptor",
  "PermissionDescriptor",
  "Permissions",
  "PermissionStatus",
  "hostname",
];

function transformMessageText(messageText: string, code: number): string {
  if (code === 2339) {
    const property = messageText
      .replace(/^Property '/, "")
      .replace(/' does not exist on type 'typeof Deno'\.$/, "");
    if (
      messageText.endsWith("on type 'typeof Deno'.") &&
      unstableDenoGlobalProperties.includes(property)
    ) {
      return `${messageText} 'Deno.${property}' is an unstable API. Did you forget to run with the '--unstable' flag?`;
    }
  }
  return messageText;
}

interface SourceInformation {
  sourceLine: string;
  lineNumber: number;
  scriptResourceName: string;
  startColumn: number;
  endColumn: number;
}

function fromDiagnosticCategory(
  category: ts.DiagnosticCategory
): DiagnosticCategory {
  switch (category) {
    case ts.DiagnosticCategory.Error:
      return DiagnosticCategory.Error;
    case ts.DiagnosticCategory.Message:
      return DiagnosticCategory.Info;
    case ts.DiagnosticCategory.Suggestion:
      return DiagnosticCategory.Suggestion;
    case ts.DiagnosticCategory.Warning:
      return DiagnosticCategory.Warning;
    default:
      throw new Error(
        `Unexpected DiagnosticCategory: "${category}"/"${ts.DiagnosticCategory[category]}"`
      );
  }
}

function getSourceInformation(
  sourceFile: ts.SourceFile,
  start: number,
  length: number
): SourceInformation {
  const scriptResourceName = sourceFile.fileName;
  const {
    line: lineNumber,
    character: startColumn,
  } = sourceFile.getLineAndCharacterOfPosition(start);
  const endPosition = sourceFile.getLineAndCharacterOfPosition(start + length);
  const endColumn =
    lineNumber === endPosition.line ? endPosition.character : startColumn;
  const lastLineInFile = sourceFile.getLineAndCharacterOfPosition(
    sourceFile.text.length
  ).line;
  const lineStart = sourceFile.getPositionOfLineAndCharacter(lineNumber, 0);
  const lineEnd =
    lineNumber < lastLineInFile
      ? sourceFile.getPositionOfLineAndCharacter(lineNumber + 1, 0)
      : sourceFile.text.length;
  const sourceLine = sourceFile.text
    .slice(lineStart, lineEnd)
    .replace(/\s+$/g, "")
    .replace("\t", " ");
  return {
    sourceLine,
    lineNumber,
    scriptResourceName,
    startColumn,
    endColumn,
  };
}

function fromDiagnosticMessageChain(
  messageChain: ts.DiagnosticMessageChain[] | undefined
): DiagnosticMessageChain[] | undefined {
  if (!messageChain) {
    return undefined;
  }

  return messageChain.map(({ messageText, code, category, next }) => {
    const message = transformMessageText(messageText, code);
    return {
      message,
      code,
      category: fromDiagnosticCategory(category),
      next: fromDiagnosticMessageChain(next),
    };
  });
}

function parseDiagnostic(
  item: ts.Diagnostic | ts.DiagnosticRelatedInformation
): DiagnosticItem {
  const {
    messageText,
    category: sourceCategory,
    code,
    file,
    start: startPosition,
    length,
  } = item;
  const sourceInfo =
    file && startPosition && length
      ? getSourceInformation(file, startPosition, length)
      : undefined;
  const endPosition =
    startPosition && length ? startPosition + length : undefined;
  const category = fromDiagnosticCategory(sourceCategory);

  let message: string;
  let messageChain: DiagnosticMessageChain | undefined;
  if (typeof messageText === "string") {
    message = transformMessageText(messageText, code);
  } else {
    message = transformMessageText(messageText.messageText, messageText.code);
    messageChain = fromDiagnosticMessageChain([messageText])![0];
  }

  const base = {
    message,
    messageChain,
    code,
    category,
    startPosition,
    endPosition,
  };

  return sourceInfo ? { ...base, ...sourceInfo } : base;
}

function parseRelatedInformation(
  relatedInformation: readonly ts.DiagnosticRelatedInformation[]
): DiagnosticItem[] {
  const result: DiagnosticItem[] = [];
  for (const item of relatedInformation) {
    result.push(parseDiagnostic(item));
  }
  return result;
}

export function fromTypeScriptDiagnostic(
  diagnostics: readonly ts.Diagnostic[]
): Diagnostic {
  const items: DiagnosticItem[] = [];
  for (const sourceDiagnostic of diagnostics) {
    const item: DiagnosticItem = parseDiagnostic(sourceDiagnostic);
    if (sourceDiagnostic.relatedInformation) {
      item.relatedInformation = parseRelatedInformation(
        sourceDiagnostic.relatedInformation
      );
    }
    items.push(item);
  }
  return { items };
}