import path from 'node:path';
import * as vscode from 'vscode';
import { diagramFromTemplate, diagramName, invalidNameReason, modelFromTemplate, TEMPLATES } from '../language/templates';
import { diagramBaseName, isArchifyFile } from '../sources/detect';
import { readText } from '../util/files';
import { DIAGRAM_EDITOR_VIEW_TYPE } from '../views/diagramView';
import { CommandContext, exists } from './context';

/** Folder for a new diagram: the clicked folder (or a file's folder), else a workspace folder. */
async function newDiagramFolder(arg?: unknown): Promise<vscode.Uri | undefined> {
  if (arg instanceof vscode.Uri) {
    const stat = await vscode.workspace.fs.stat(arg);
    return stat.type & vscode.FileType.Directory ? arg : vscode.Uri.joinPath(arg, '..');
  }
  const folders = vscode.workspace.workspaceFolders ?? [];
  if (folders.length <= 1) return folders[0]?.uri;
  return (await vscode.window.showWorkspaceFolderPick({ placeHolder: 'Folder for the new diagram' }))?.uri;
}

export function newDiagramCommands(ctx: CommandContext): vscode.Disposable[] {
  return [
    vscode.commands.registerCommand('archify.newDiagram', async (arg?: unknown) => {
      const template = await vscode.window.showQuickPick(
        TEMPLATES.map((item) => ({ label: item.label, description: item.description, template: item })),
        { title: 'Archify | New Diagram', placeHolder: 'Kind of diagram' },
      );
      if (!template) return;
      const { file, defaultName, fixedName } = template.template;

      const folder = await newDiagramFolder(arg);
      let target: vscode.Uri | undefined;
      if (folder && fixedName) {
        target = vscode.Uri.joinPath(folder, fixedName);
        if (await exists(target)) {
          vscode.window.showWarningMessage(`Archify: ${vscode.workspace.asRelativePath(folder, true)} already has a ${fixedName}.`);
          return;
        }
      } else if (folder) {
        const name = await vscode.window.showInputBox({
          title: 'Archify | New Diagram',
          prompt: `File name in ${vscode.workspace.asRelativePath(folder, true)}`,
          value: defaultName,
          validateInput: async (value) =>
            invalidNameReason(value) ??
            ((await exists(vscode.Uri.joinPath(folder, `${diagramName(value)}.archify`))) ? `${diagramName(value)}.archify already exists.` : undefined),
        });
        if (name === undefined) return;
        target = vscode.Uri.joinPath(folder, `${diagramName(name)}.archify`);
      } else {
        // No workspace: let the user choose where to save.
        target = await vscode.window.showSaveDialog({
          title: 'Archify | New Diagram',
          filters: { 'Archify Diagram': ['archify'] },
          saveLabel: 'Create',
        });
        if (!target) return;
        if (!isArchifyFile(target.path)) target = target.with({ path: `${target.path}.archify` });
      }

      const templateText = await readText(vscode.Uri.joinPath(ctx.extension.extensionUri, 'templates', file));
      const text = fixedName
        ? modelFromTemplate(templateText, path.basename(path.dirname(target.fsPath)))
        : diagramFromTemplate(templateText, diagramBaseName(target.path));
      await vscode.workspace.fs.writeFile(target, Buffer.from(text, 'utf8'));
      await vscode.commands.executeCommand('vscode.openWith', target, DIAGRAM_EDITOR_VIEW_TYPE);
    }),
  ];
}