/**
 * @since 1.0.0
 */
import * as Effect from 'effect/Effect'

/**
 * Export style options for generated code
 *
 * @since 1.0.0
 * @category Types
 */
export type ExportStyle = 'named' | 'namespace' | 'default'

/**
 * Options for the code emitter
 *
 * @since 1.0.0
 * @category Types
 */
export interface EmitterOptions {
  /**
   * Export style for generated code
   * - 'named': Named exports only (default)
   * - 'namespace': Named exports plus namespace object
   * - 'default': Named exports plus default export object
   */
  readonly exportStyle?: ExportStyle
  /**
   * List of export names to include in namespace/default export
   * Required when exportStyle is 'namespace' or 'default'
   */
  readonly exportNames?: ReadonlyArray<string>
  /**
   * Name for the namespace export (only used with 'namespace' style)
   */
  readonly namespaceName?: string
}

/**
 * Emit final TypeScript code with file header
 *
 * @since 1.0.0
 * @category Generation
 */
export const emit = (code: string, options?: EmitterOptions): Effect.Effect<string> =>
  Effect.sync(() => {
    const header = [
      '/**',
      ' * Generated by @davidgoli/openapi-server-gen',
      ' *',
      ' * DO NOT EDIT THIS FILE MANUALLY',
      ' *',
      ' * This file was automatically generated from an OpenAPI specification.',
      ' * To regenerate, run the generator again with your OpenAPI spec.',
      ' */',
    ].join('\n')

    let output = `${header}\n\n${code}`

    // Add additional exports based on style
    const exportStyle = options?.exportStyle ?? 'named'
    const exportNames = options?.exportNames ?? []

    if (exportStyle === 'namespace' && exportNames.length > 0) {
      const namespaceName = options?.namespaceName ?? 'Api'
      const namespaceExport = `\nexport const ${namespaceName} = {\n  ${exportNames.join(',\n  ')}\n}`
      output += namespaceExport
    } else if (exportStyle === 'default' && exportNames.length > 0) {
      const defaultExport = `\nexport default {\n  ${exportNames.join(',\n  ')}\n}`
      output += defaultExport
    }

    return `${output}\n`
  })