import { z } from 'astro/zod'

const operationCClientSchema = z.enum(['libcurl'])
const operationCSharpClientSchema = z.enum(['httpclient'])
const operationGoClientSchema = z.enum(['nethttp'])
const operationJavaClientSchema = z.enum(['nethttp', 'okhttp'])
const operationJavaScriptClientSchema = z.enum(['axios', 'fetch'])
const operationKotlinClientSchema = z.enum(['okhttp'])
const operationRustClientSchema = z.enum(['reqwest'])
const operationShellClientSchema = z.enum(['curl', 'wget'])

const operationReferenceSchema = z.discriminatedUnion('target', [
  z.object({ target: z.literal('c'), client: operationCClientSchema }),
  z.object({ target: z.literal('csharp'), client: operationCSharpClientSchema }),
  z.object({ target: z.literal('go'), client: operationGoClientSchema }),
  z.object({ target: z.literal('java'), client: operationJavaClientSchema }),
  z.object({ target: z.literal('javascript'), client: operationJavaScriptClientSchema }),
  z.object({ target: z.literal('kotlin'), client: operationKotlinClientSchema }),
  z.object({ target: z.literal('rust'), client: operationRustClientSchema }),
  z.object({ target: z.literal('shell'), client: operationShellClientSchema }),
])

const operationClientsSchema = z
  .object({
    c: z.array(operationCClientSchema).optional(),
    csharp: z.array(operationCSharpClientSchema).optional(),
    go: z.array(operationGoClientSchema).optional(),
    java: z.array(operationJavaClientSchema).optional(),
    javascript: z.array(operationJavaScriptClientSchema).optional(),
    kotlin: z.array(operationKotlinClientSchema).optional(),
    rust: z.array(operationRustClientSchema).optional(),
    shell: z.array(operationShellClientSchema).optional(),
  })
  .partial()

const defaultOperationClients = {
  javascript: ['fetch'],
  shell: ['curl'],
} as const satisfies z.input<typeof operationClientsSchema>

const defaultOperationReference = {
  target: 'shell',
  client: 'curl',
} as const satisfies z.input<typeof operationReferenceSchema>

const operationConfigSchema = z
  .object({
    /**
     * Defines the enabled clients for which operation snippets should be generated.
     */
    clients: operationClientsSchema.default(defaultOperationClients),
    /**
     * Defines the operation snippet that should be used by default on operation pages among the enabled operation
     * snippet clients.
     */
    default: operationReferenceSchema.optional(),
  })
  .transform((value, ctx) => {
    for (const [target, clients] of Object.entries(value.clients)) {
      if (!clients) continue

      if (new Set(clients).size !== clients.length) {
        ctx.addIssue({
          code: 'custom',
          message: 'Operation snippet clients must be unique.',
          path: ['clients', target],
        })

        return z.NEVER
      }
    }

    if (value.default && !includesOperationReference(value.clients, value.default)) {
      ctx.addIssue({
        code: 'custom',
        message: 'The default operation snippet client must be one of the enabled operation snippet clients.',
        path: ['default'],
      })

      return z.NEVER
    }

    const defaultReference = getDefaultOperationReference(value.clients, value.default)

    if (!defaultReference) {
      ctx.addIssue({
        code: 'custom',
        message: 'At least one operation snippet client must be enabled.',
        path: ['clients'],
      })

      return z.NEVER
    }

    return {
      clients: Object.entries(value.clients).flatMap(([target, clients]) =>
        (clients ?? []).map((client) => ({ target: target, client }) as SnippetOperationReference),
      ),
      default: defaultReference,
    }
  })

const defaultOperationConfig = operationConfigSchema.parse({})

const operationSchema = z
  .union([z.literal(true), z.literal(false), operationConfigSchema])
  .transform((value) => (value === true ? defaultOperationConfig : value))
  .default(defaultOperationConfig)

export const SnippetsSchema = z
  .object({
    /**
     * Controls whether autogenerated operation snippets are available on operation pages.
     * Authored `x-codeSamples` are not affected by this option and are always shown when available.
     */
    operation: operationSchema,
    /**
     * Controls whether autogenerated request body snippets are available in request body sections for JSON-like and
     * URL-encoded form request body media types.
     * Authored request body examples are not affected by this option and are always shown when available.
     */
    requestBody: z.boolean().default(true),
    /**
     * Controls whether autogenerated response snippets are available in response sections for JSON-like response media
     * types.
     * Authored response examples are not affected by this option and are always shown when available.
     */
    response: z.boolean().default(true),
  })
  .default({ operation: defaultOperationConfig, requestBody: true, response: true })

function includesOperationReference(clients: SnippetOperationClients, reference: SnippetOperationReference): boolean {
  return clients[reference.target]?.includes(reference.client as never) ?? false
}

function getDefaultOperationReference(
  clients: SnippetOperationClients,
  reference: SnippetOperationReference | undefined,
): SnippetOperationReference | undefined {
  if (reference) return reference
  if (includesOperationReference(clients, defaultOperationReference)) return defaultOperationReference

  for (const [target, targetClients] of Object.entries(clients)) {
    const [client] = targetClients ?? []
    if (client) return { target, client } as SnippetOperationReference
  }

  return
}

type SnippetOperationClients = z.output<typeof operationClientsSchema>

export type SnippetOperationReference = z.output<typeof operationReferenceSchema>