feat(core): temp workspace provider implementation.

Signed-off-by: Braden Mars <bradenmars@bradenmars.me>

packages/openapi-generator-clients/src/workspace.ts

@@ -0,0 +1,43 @@
+import type {
+	GeneratorConfig,
+	Workspace,
+	WorkspaceProvider,
+} from '@openapi-generator-clients/types'
+import {Record as ImRecord, type RecordOf} from 'immutable'
+import {getTempDir} from '@openapi-generator-clients/utils'
+import path from 'pathe'
+import {partial} from 'rambdax/immutable.js'
+import fse from 'fs-extra'
+
+export const WorkspaceRecord = ImRecord<Workspace>({
+	rootPath: '',
+	templatesPath: '',
+	configPath: '',
+	outputPath: '',
+})
+export interface WorkspaceRecord extends RecordOf<Workspace> {}
+
+export const temporaryWorkspaceProvider: WorkspaceProvider<WorkspaceRecord> = {
+	workspace: WorkspaceRecord(),
+	async create(outputDir: string, overwrite = false) {
+		const root = getTempDir()
+		const resolve = partial(path.resolve, [root])
+		this.workspace = WorkspaceRecord({
+			rootPath: root,
+			templatesPath: resolve('./templates'),
+			configPath: resolve('./config.json'),
+			outputPath: overwrite ? outputDir : resolve(outputDir),
+		})
+		await fse.ensureDir(this.workspace.templatesPath)
+		return this
+	},
+	async addTemplatePath(path: string) {
+		const templatesDir = this.workspace.templatesPath
+		await fse.copy(path, templatesDir, {overwrite: true, errorOnExist: false})
+		return this
+	},
+	async setConfig(config: GeneratorConfig) {
+		await fse.writeJson(this.workspace.configPath, config, {spaces: 2})
+		return this
+	},
+}