import { isAbsolute } from 'node:path'
import { z } from 'zod'
import { isDeepSeekHarnessCompatibleBaseUrl } from '../../shared/deepseek-harness-compatibility'
import {
  modelRequestHeadersSchema
} from '../../shared/model-request-customization'
import {
  runtimeExtensionConfigurationSchema,
  runtimeExtensionIdSchema
} from '../../shared/runtime-extension-contracts'
import { bundledDeepSeekHarnessVersion } from './bundled-runtimes'

export const DEEPSEEK_HARNESS_CONTROL_PROTOCOL =
  'goodbuddy.deepseek-harness.control'
export const DEEPSEEK_HARNESS_CONTROL_VERSION = 3
export const DEEPSEEK_HARNESS_HOST_VERSION =
  bundledDeepSeekHarnessVersion
export const DEEPSEEK_HARNESS_CREDENTIAL_REF =
  'GOODBUDDY_HARNESS_MODEL_API_KEY'
export const DEEPSEEK_HARNESS_MAX_FRAME_BYTES =
  8 * 1024 * 1024
export const DEEPSEEK_HARNESS_EXTENSION_ACTIVATION_TIMEOUT_MS =
  5_000
export const DEEPSEEK_HARNESS_EXTENSION_DISPOSAL_TIMEOUT_MS =
  1_000
export const DEEPSEEK_HARNESS_TOTAL_EXTENSION_ACTIVATION_TIMEOUT_MS =
  90_000
const DEEPSEEK_HARNESS_HOST_STARTUP_OVERHEAD_MS = 10_000
const DEEPSEEK_HARNESS_STARTUP_FAILURE_CLEANUP_MS = 2_000

export function deepSeekHarnessStartupBudget(
  extensionCount: number
): {
  hostTimeoutMs: number
  mainTimeoutMs: number
} {
  const boundedExtensionCount = Math.max(
    0,
    Math.floor(extensionCount)
  )
  const extensionSequenceMs = Math.min(
    DEEPSEEK_HARNESS_TOTAL_EXTENSION_ACTIVATION_TIMEOUT_MS +
      DEEPSEEK_HARNESS_EXTENSION_DISPOSAL_TIMEOUT_MS,
    boundedExtensionCount *
      (DEEPSEEK_HARNESS_EXTENSION_ACTIVATION_TIMEOUT_MS +
        DEEPSEEK_HARNESS_EXTENSION_DISPOSAL_TIMEOUT_MS)
  )
  const hostTimeoutMs =
    DEEPSEEK_HARNESS_HOST_STARTUP_OVERHEAD_MS +
    extensionSequenceMs
  return {
    hostTimeoutMs,
    mainTimeoutMs:
      hostTimeoutMs +
      DEEPSEEK_HARNESS_STARTUP_FAILURE_CLEANUP_MS
  }
}

const skillPackageSchema = z
  .object({
    id: z
      .string()
      .min(1)
      .max(128)
      .regex(/^[a-z0-9]+(?:-[a-z0-9]+)*$/u),
    directory: z.string().min(1).max(32_768).refine(isAbsolute)
  })
  .strict()

const extensionPackageSchema = z
  .object({
    id: runtimeExtensionIdSchema,
    entrypoint: z.string().min(1).max(32_768).refine(isAbsolute),
    configuration: runtimeExtensionConfigurationSchema
  })
  .strict()

export const controlledHarnessHostConfigSchema = z
  .object({
    workspace: z.string().min(1).max(32_768).refine(isAbsolute),
    dshHome: z.string().min(1).max(32_768).refine(isAbsolute),
    baseUrl: z
      .url()
      .max(2_048)
      .refine(isDeepSeekHarnessCompatibleBaseUrl),
    api: z.literal('openai-completions'),
    provider: z.literal('goodbuddy'),
    model: z.string().min(1).max(128),
    supportsImageInput: z.boolean(),
    requestHeaders: modelRequestHeadersSchema,
    harnessVersion: z.literal(DEEPSEEK_HARNESS_HOST_VERSION),
    credentialRefs: z
      .tuple([z.literal(DEEPSEEK_HARNESS_CREDENTIAL_REF)])
      .readonly(),
    skillPackages: z.array(skillPackageSchema).max(64),
    extensionPackages: z.array(extensionPackageSchema).max(64),
    maxFrameBytes: z.literal(DEEPSEEK_HARNESS_MAX_FRAME_BYTES)
  })
  .strict()

export type ControlledHarnessBootstrapConfig = z.infer<
  typeof controlledHarnessHostConfigSchema
>

export type DeepSeekHarnessControlMessage =
  | {
      protocol: typeof DEEPSEEK_HARNESS_CONTROL_PROTOCOL
      version: typeof DEEPSEEK_HARNESS_CONTROL_VERSION
      type: 'start'
      config: ControlledHarnessBootstrapConfig
    }
  | {
      protocol: typeof DEEPSEEK_HARNESS_CONTROL_PROTOCOL
      version: typeof DEEPSEEK_HARNESS_CONTROL_VERSION
      type: 'ready'
      failedExtensionIds: readonly string[]
    }
  | {
      protocol: typeof DEEPSEEK_HARNESS_CONTROL_PROTOCOL
      version: typeof DEEPSEEK_HARNESS_CONTROL_VERSION
      type: 'fatal'
      code: string
    }

export function parseHarnessControlMessage(
  value: unknown
): DeepSeekHarnessControlMessage | undefined {
  if (
    !value ||
    typeof value !== 'object' ||
    Array.isArray(value)
  ) {
    return undefined
  }
  const record = value as Record<string, unknown>
  if (
    record.protocol !== DEEPSEEK_HARNESS_CONTROL_PROTOCOL ||
    record.version !== DEEPSEEK_HARNESS_CONTROL_VERSION
  ) {
    return undefined
  }
  if (
    record.type === 'ready' &&
    Object.keys(record).length === 4 &&
    Array.isArray(record.failedExtensionIds)
  ) {
    const failedExtensionIds = z
      .array(runtimeExtensionIdSchema)
      .max(64)
      .safeParse(record.failedExtensionIds)
    return failedExtensionIds.success
      ? {
          protocol: DEEPSEEK_HARNESS_CONTROL_PROTOCOL,
          version: DEEPSEEK_HARNESS_CONTROL_VERSION,
          type: 'ready',
          failedExtensionIds: failedExtensionIds.data
        }
      : undefined
  }
  if (
    record.type === 'fatal' &&
    Object.keys(record).length === 4 &&
    typeof record.code === 'string' &&
    /^[A-Z][A-Z0-9_]{0,63}$/u.test(record.code)
  ) {
    return record as DeepSeekHarnessControlMessage
  }
  if (
    record.type === 'start' &&
    Object.keys(record).length === 4
  ) {
    const parsed = controlledHarnessHostConfigSchema.safeParse(
      record.config
    )
    return parsed.success
      ? {
          protocol: DEEPSEEK_HARNESS_CONTROL_PROTOCOL,
          version: DEEPSEEK_HARNESS_CONTROL_VERSION,
          type: 'start',
          config: parsed.data
        }
      : undefined
  }
  return undefined
}