import { ColorSet, prepareColorSet } from './color-set/index.js';
import { BuiltInColorSet, resolveColorSet } from './color-set/all.js';
import type { Template, OutputFile, RenderOptions } from './template/index.js';
import { BuiltInTemplate, resolveTemplate } from './template/all.js';
import { OutputFileTransform, noopTransform } from './transform/index.js';

export async function* themer<T extends { path: string } = OutputFile>(
  colorSets: (BuiltInColorSet | ColorSet)[],
  templates: (BuiltInTemplate | Template)[],
  options: RenderOptions,
  transform: OutputFileTransform<T> = noopTransform,
): AsyncGenerator<T | OutputFile> {
  for (const colorSet of colorSets) {
    const resolvedColorSet = resolveColorSet(colorSet);
    const fullColorSet = prepareColorSet(resolvedColorSet);
    const resolvedTemplates = templates.map(resolveTemplate);
    const instructions: string[] = [`# themer - ${fullColorSet.name}`];
    const rootDir = fullColorSet.name;
    for (const template of resolvedTemplates) {
      const templatePaths: Set<string> = new Set();
      for await (const renderedFile of template.render(fullColorSet, options)) {
        for await (const file of transform(renderedFile)) {
          const path = `${template.name}/${file.path}`;
          yield {
            ...file,
            path: `${rootDir}/${path}`,
          };
          templatePaths.add(path);
        }
      }
      instructions.push(`## ${template.name}`);
      instructions.push(
        template.renderInstructions([...templatePaths], fullColorSet).trim(),
      );
    }
    yield {
      path: `${rootDir}/README.md`,
      content: instructions.join('\n\n'),
    };
  }
}