import * as vscode from 'vscode';
import { MODEL_EXAMPLES, mainFromExample } from '../language/examples';
import { diagramName, invalidNameReason } from '../language/templates';
import { DECISION_EXT, slugify } from '../model/decisions';
import { MAIN_FILE } from '../model/format';
import { DECISION_VIEW_TYPE } from '../views/decisionView';
import { readText } from '../util/files';
import { DIAGRAM_EDITOR_VIEW_TYPE } from '../views/diagramView';
import { CommandContext, exists, targetUri } from './context';

/** Folder the new model folder goes into: the clicked folder (or a file's folder), else a workspace folder. */
async function parentFolder(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 model' }))?.uri;
}

export function modelCommands(ctx: CommandContext): vscode.Disposable[] {
  return [
    // Opens the model page (main.archify) of the model the current file is in.
    vscode.commands.registerCommand('archify.openModel', async (arg?: unknown) => {
      const uri = targetUri(ctx, arg);
      const root = uri ? await ctx.models.rootOf(uri) : undefined;
      if (!root) {
        vscode.window.showInformationMessage(`Archify: this file is not inside a model (no ${MAIN_FILE} in a folder above it).`);
        return;
      }
      await vscode.commands.executeCommand('vscode.openWith', vscode.Uri.joinPath(root, MAIN_FILE), DIAGRAM_EDITOR_VIEW_TYPE, vscode.ViewColumn.Active);
    }),

    // Creates a decision file in the clicked folder of a model and opens it.
    vscode.commands.registerCommand('archify.newDecision', async (arg?: unknown) => {
      const folder = await parentFolder(arg);
      if (!folder) return;
      const root = await ctx.models.rootOf(vscode.Uri.joinPath(folder, 'x'));
      if (!root) {
        vscode.window.showWarningMessage(`Archify: ${vscode.workspace.asRelativePath(folder, true)} is not inside a model (no ${MAIN_FILE} in it or a folder above it). Decisions belong to a model.`);
        return;
      }
      const index = await ctx.models.index(root);
      const title = await vscode.window.showInputBox({
        title: 'Archify | New Decision',
        prompt: `Title of the decision (file goes into ${vscode.workspace.asRelativePath(folder, true)})`,
        placeHolder: 'OpenSearch for product search',
        validateInput: async (value) => {
          if (!value.trim()) return 'Enter a title.';
          const id = slugify(value);
          if (index.decisions.decisions.has(id)) return `A decision with id "${id}" already exists in this model.`;
          if (await exists(vscode.Uri.joinPath(folder, `${id}${DECISION_EXT}`))) return `${id}${DECISION_EXT} already exists.`;
          return undefined;
        },
      });
      if (title === undefined) return;
      const id = slugify(title);
      const target = vscode.Uri.joinPath(folder, `${id}${DECISION_EXT}`);
      const template = await readText(vscode.Uri.joinPath(ctx.extension.extensionUri, 'templates', 'decision.archify-decision'));
      const today = new Date().toISOString().slice(0, 10);
      const text = template.replace('__ID__', id).replace('__TITLE__', JSON.stringify(title.trim())).replace('__DATE__', today);
      await vscode.workspace.fs.writeFile(target, Buffer.from(text, 'utf8'));
      await vscode.commands.executeCommand('vscode.openWith', target, DECISION_VIEW_TYPE);
    }),

    // Creates a new model folder from one of the shipped examples and opens its model page.
    vscode.commands.registerCommand('archify.newModel', async (arg?: unknown) => {
      const picked = await vscode.window.showQuickPick(
        MODEL_EXAMPLES.map((example) => ({ label: example.label, description: example.description, example })),
        { title: 'Archify | New Model', placeHolder: 'Example to start from' },
      );
      if (!picked) return;
      const { example } = picked;

      let parent = await parentFolder(arg);
      if (!parent) {
        const chosen = await vscode.window.showOpenDialog({ title: 'Archify | New Model', canSelectFiles: false, canSelectFolders: true, openLabel: 'Create model here' });
        parent = chosen?.[0];
        if (!parent) return;
      }
      const name = await vscode.window.showInputBox({
        title: 'Archify | New Model',
        prompt: `Folder name in ${vscode.workspace.asRelativePath(parent, true)}`,
        value: example.folder,
        validateInput: async (value) =>
          invalidNameReason(value) ?? ((await exists(vscode.Uri.joinPath(parent, diagramName(value)))) ? `${diagramName(value)} already exists.` : undefined),
      });
      if (name === undefined) return;
      const folderName = diagramName(name);
      const target = vscode.Uri.joinPath(parent, folderName);
      if (await exists(target)) {
        vscode.window.showWarningMessage(`Archify: ${vscode.workspace.asRelativePath(target, true)} already exists.`);
        return;
      }

      const source = vscode.Uri.joinPath(ctx.extension.extensionUri, 'templates', 'models', example.folder);
      await vscode.workspace.fs.copy(source, target, { overwrite: false });
      const main = vscode.Uri.joinPath(target, MAIN_FILE);
      await vscode.workspace.fs.writeFile(main, Buffer.from(mainFromExample(await readText(main), folderName, example), 'utf8'));
      await vscode.commands.executeCommand('vscode.openWith', main, DIAGRAM_EDITOR_VIEW_TYPE);
    }),
  ];
}