import {
  editor,
  IDisposable,
  IMarkdownString,
  languages,
  MarkerSeverity,
  Position,
  Range,
  Uri,
} from 'monaco-editor/esm/vs/editor/editor.api';
import * as ls from 'vscode-languageserver-types';
import { CustomFormatterOptions } from 'yaml-language-server/lib/esm/languageservice/yamlLanguageService';

import { YAMLWorker } from './yamlWorker';

export type WorkerAccessor = (...more: Uri[]) => PromiseLike<YAMLWorker>;

// --- diagnostics --- ---

function toSeverity(lsSeverity: ls.DiagnosticSeverity): MarkerSeverity {
  switch (lsSeverity) {
    case ls.DiagnosticSeverity.Error:
      return MarkerSeverity.Error;
    case ls.DiagnosticSeverity.Warning:
      return MarkerSeverity.Warning;
    case ls.DiagnosticSeverity.Information:
      return MarkerSeverity.Info;
    case ls.DiagnosticSeverity.Hint:
      return MarkerSeverity.Hint;
    default:
      return MarkerSeverity.Info;
  }
}

function toDiagnostics(resource: Uri, diag: ls.Diagnostic): editor.IMarkerData {
  const code = typeof diag.code === 'number' ? String(diag.code) : (diag.code as string);

  return {
    severity: toSeverity(diag.severity),
    startLineNumber: diag.range.start.line + 1,
    startColumn: diag.range.start.character + 1,
    endLineNumber: diag.range.end.line + 1,
    endColumn: diag.range.end.character + 1,
    message: diag.message,
    code,
    source: diag.source,
  };
}

export function createDiagnosticsAdapter(
  languageId: string,
  getWorker: WorkerAccessor,
  defaults: languages.yaml.LanguageServiceDefaults,
): IDisposable {
  let disposables: IDisposable[] = [];
  const listeners: Record<string, IDisposable> = Object.create(null);

  const resetSchema = async (resource: Uri): Promise<void> => {
    const worker = await getWorker();
    worker.resetSchema(String(resource));
  };

  const doValidate = async (resource: Uri, languageId: string): Promise<void> => {
    const worker = await getWorker(resource);
    const diagnostics = await worker.doValidation(String(resource));
    const markers = diagnostics.map((d) => toDiagnostics(resource, d));
    const model = editor.getModel(resource);
    if (model.getModeId() === languageId) {
      editor.setModelMarkers(model, languageId, markers);
    }
  };

  const onModelAdd = (model: editor.IModel): void => {
    const modeId = model.getModeId();
    if (modeId !== languageId) {
      return;
    }

    let handle: number;
    listeners[String(toString)] = model.onDidChangeContent(() => {
      clearTimeout(handle);
      handle = setTimeout(() => doValidate(model.uri, modeId), 500);
    });

    doValidate(model.uri, modeId);
  };

  const onModelRemoved = (model: editor.IModel): void => {
    editor.setModelMarkers(model, languageId, []);
    const uriStr = String(model.uri);
    const listener = listeners[uriStr];
    if (listener) {
      listener.dispose();
      delete listeners[uriStr];
    }
  };

  disposables.push(
    editor.onDidCreateModel(onModelAdd),
    editor.onWillDisposeModel((model) => {
      onModelRemoved(model);
      resetSchema(model.uri);
    }),
    editor.onDidChangeModelLanguage((event) => {
      onModelRemoved(event.model);
      onModelAdd(event.model);
      resetSchema(event.model.uri);
    }),
    defaults.onDidChange(() => {
      editor.getModels().forEach((model) => {
        if (model.getModeId() === languageId) {
          onModelRemoved(model);
          onModelAdd(model);
        }
      });
    }),
    {
      dispose: () => {
        editor.getModels().forEach(onModelRemoved);
        for (const disposable of Object.values(listeners)) {
          disposable.dispose();
        }
      },
    },
  );

  editor.getModels().forEach(onModelAdd);

  return {
    dispose() {
      disposables.forEach((d) => d && d.dispose());
      disposables = [];
    },
  };
}

// --- completion ------

function fromPosition(position: Position): ls.Position {
  if (!position) {
    return;
  }
  return { character: position.column - 1, line: position.lineNumber - 1 };
}

function toRange(range: ls.Range): Range {
  if (!range) {
    return;
  }
  return new Range(
    range.start.line + 1,
    range.start.character + 1,
    range.end.line + 1,
    range.end.character + 1,
  );
}

function toCompletionItemKind(kind: languages.CompletionItemKind): languages.CompletionItemKind {
  const mItemKind = languages.CompletionItemKind;

  switch (kind) {
    case ls.CompletionItemKind.Text:
      return mItemKind.Text;
    case ls.CompletionItemKind.Method:
      return mItemKind.Method;
    case ls.CompletionItemKind.Function:
      return mItemKind.Function;
    case ls.CompletionItemKind.Constructor:
      return mItemKind.Constructor;
    case ls.CompletionItemKind.Field:
      return mItemKind.Field;
    case ls.CompletionItemKind.Variable:
      return mItemKind.Variable;
    case ls.CompletionItemKind.Class:
      return mItemKind.Class;
    case ls.CompletionItemKind.Interface:
      return mItemKind.Interface;
    case ls.CompletionItemKind.Module:
      return mItemKind.Module;
    case ls.CompletionItemKind.Property:
      return mItemKind.Property;
    case ls.CompletionItemKind.Unit:
      return mItemKind.Unit;
    case ls.CompletionItemKind.Value:
      return mItemKind.Value;
    case ls.CompletionItemKind.Enum:
      return mItemKind.Enum;
    case ls.CompletionItemKind.Keyword:
      return mItemKind.Keyword;
    case ls.CompletionItemKind.Snippet:
      return mItemKind.Snippet;
    case ls.CompletionItemKind.Color:
      return mItemKind.Color;
    case ls.CompletionItemKind.File:
      return mItemKind.File;
    case ls.CompletionItemKind.Reference:
      return mItemKind.Reference;
    default:
      return mItemKind.Property;
  }
}

function toTextEdit(textEdit: ls.TextEdit): editor.ISingleEditOperation {
  if (!textEdit) {
    return;
  }
  return {
    range: toRange(textEdit.range),
    text: textEdit.newText,
  };
}

export function createCompletionItemProvider(
  getWorker: WorkerAccessor,
): languages.CompletionItemProvider {
  return {
    triggerCharacters: [' ', ':'],

    async provideCompletionItems(model, position) {
      const resource = model.uri;

      const worker = await getWorker(resource);
      const info = await worker.doComplete(String(resource), fromPosition(position));
      if (!info) {
        return;
      }

      const wordInfo = model.getWordUntilPosition(position);
      const wordRange = new Range(
        position.lineNumber,
        wordInfo.startColumn,
        position.lineNumber,
        wordInfo.endColumn,
      );

      const items = info.items.map((entry) => {
        const item: languages.CompletionItem = {
          label: entry.label,
          insertText: entry.insertText || entry.label,
          sortText: entry.sortText,
          filterText: entry.filterText,
          documentation: entry.documentation,
          detail: entry.detail,
          kind: toCompletionItemKind(entry.kind),
          range: wordRange,
        };
        if (entry.textEdit) {
          item.range = toRange(
            'range' in entry.textEdit ? entry.textEdit.range : entry.textEdit.replace,
          );
          item.insertText = entry.textEdit.newText;
        }
        if (entry.additionalTextEdits) {
          item.additionalTextEdits = entry.additionalTextEdits.map(toTextEdit);
        }
        if (entry.insertTextFormat === ls.InsertTextFormat.Snippet) {
          item.insertTextRules = languages.CompletionItemInsertTextRule.InsertAsSnippet;
        }
        return item;
      });

      return {
        incomplete: info.isIncomplete,
        suggestions: items,
      };
    },
  };
}

function isMarkupContent(thing: unknown): thing is ls.MarkupContent {
  return thing && typeof thing === 'object' && typeof (thing as ls.MarkupContent).kind === 'string';
}

function toMarkdownString(entry: ls.MarkedString | ls.MarkupContent): IMarkdownString {
  if (typeof entry === 'string') {
    return {
      value: entry,
    };
  }
  if (isMarkupContent(entry)) {
    if (entry.kind === 'plaintext') {
      return {
        value: entry.value.replace(/[!#()*+.[\\\]_`{}-]/g, '\\$&'),
      };
    }
    return {
      value: entry.value,
    };
  }

  return { value: `\`\`\`${entry.language}\n${entry.value}\n\`\`\`\n` };
}

function toMarkedStringArray(
  contents: ls.MarkedString | ls.MarkedString[] | ls.MarkupContent,
): IMarkdownString[] {
  if (!contents) {
    return;
  }
  if (Array.isArray(contents)) {
    return contents.map(toMarkdownString);
  }
  return [toMarkdownString(contents)];
}

// --- hover ------

export function createHoverProvider(getWorker: WorkerAccessor): languages.HoverProvider {
  return {
    async provideHover(model, position) {
      const resource = model.uri;

      const worker = await getWorker(resource);
      const info = await worker.doHover(String(resource), fromPosition(position));
      if (!info) {
        return;
      }
      return {
        range: toRange(info.range),
        contents: toMarkedStringArray(info.contents),
      };
    },
  };
}

// --- document symbols ------

function toSymbolKind(kind: ls.SymbolKind): languages.SymbolKind {
  const mKind = languages.SymbolKind;

  switch (kind) {
    case ls.SymbolKind.File:
      return mKind.Array;
    case ls.SymbolKind.Module:
      return mKind.Module;
    case ls.SymbolKind.Namespace:
      return mKind.Namespace;
    case ls.SymbolKind.Package:
      return mKind.Package;
    case ls.SymbolKind.Class:
      return mKind.Class;
    case ls.SymbolKind.Method:
      return mKind.Method;
    case ls.SymbolKind.Property:
      return mKind.Property;
    case ls.SymbolKind.Field:
      return mKind.Field;
    case ls.SymbolKind.Constructor:
      return mKind.Constructor;
    case ls.SymbolKind.Enum:
      return mKind.Enum;
    case ls.SymbolKind.Interface:
      return mKind.Interface;
    case ls.SymbolKind.Function:
      return mKind.Function;
    case ls.SymbolKind.Variable:
      return mKind.Variable;
    case ls.SymbolKind.Constant:
      return mKind.Constant;
    case ls.SymbolKind.String:
      return mKind.String;
    case ls.SymbolKind.Number:
      return mKind.Number;
    case ls.SymbolKind.Boolean:
      return mKind.Boolean;
    case ls.SymbolKind.Array:
      return mKind.Array;
    default:
      return mKind.Function;
  }
}

function toDocumentSymbol(item: ls.DocumentSymbol): languages.DocumentSymbol {
  return {
    detail: '',
    range: toRange(item.range),
    name: item.name,
    kind: toSymbolKind(item.kind),
    selectionRange: toRange(item.selectionRange),
    children: item.children.map((child) => toDocumentSymbol(child)),
    tags: [],
  };
}

export function createDocumentSymbolProvider(
  getWorker: WorkerAccessor,
): languages.DocumentSymbolProvider {
  return {
    async provideDocumentSymbols(model) {
      const resource = model.uri;

      const worker = await getWorker(resource);
      const items = await worker.findDocumentSymbols(String(resource));
      if (!items) {
        return;
      }
      return items.map((item) => toDocumentSymbol(item));
    },
  };
}

function fromFormattingOptions(
  options: languages.FormattingOptions,
): CustomFormatterOptions & ls.FormattingOptions {
  return {
    tabSize: options.tabSize,
    insertSpaces: options.insertSpaces,
    ...options,
  };
}

export function createDocumentFormattingEditProvider(
  getWorker: WorkerAccessor,
): languages.DocumentFormattingEditProvider {
  return {
    async provideDocumentFormattingEdits(model, options) {
      const resource = model.uri;

      const worker = await getWorker(resource);
      const edits = await worker.format(String(resource), fromFormattingOptions(options));
      if (!edits || edits.length === 0) {
        return;
      }
      return edits.map(toTextEdit);
    },
  };
}