/**
 * REAL-composition proof: the shipped gateway YAML shape (session +
 * projection registry + credentials + openrouter-usage) boots through the
 * vendored Loader, the service default-export survives, a key resolved from
 * the credentials document lets a mocked OpenRouter fetch populate the
 * pricing table and the balance, and a logged step serves a priced
 * `openRouterCost` view through the composed registry.
 */

import { mkdtemp, rm, writeFile } from 'node:fs/promises'
import { tmpdir } from 'node:os'
import { join } from 'node:path'
import { pathToFileURL } from 'node:url'
import { afterEach, describe, expect, it, vi } from 'vitest'
import { Context } from '@deepseek-ai/cordis'
import Loader from '@deepseek-ai/cordis-plugin-loader'
import Include from '@deepseek-ai/cordis-plugin-include'
import { createMessage } from '@deepseek-ai/dsh-llm'
import SessionStore from '@deepseek-ai/dsh-session'
import SessionProjectionRegistry from '@deepseek-ai/dsh-session-projection'
import LocalCredentialProvider from '@deepseek-ai/dsh-credentials-local'
import FileSettingsProvider from '@deepseek-ai/dsh-settings-file'
import OpenRouterUsageGateway from '@deepseek-ai/dsh-openrouter-usage'

let root: string | undefined
let context: Context | undefined

afterEach(async () => {
  await context?.fiber.dispose()
  context = undefined
  if (root !== undefined) await rm(root, { recursive: true, force: true })
  root = undefined
  vi.unstubAllGlobals()
})

/** Mock OpenRouter's read endpoints and record the calls. */
function stubOpenRouter() {
  const pricing = [
    { id: 'deepseek/deepseek-chat', pricing: { prompt: '0.0000014', completion: '0.0000028', request: '0' } },
  ]
  const credits = { total_credits: 42, total_usage: 1, is_free_tier: false }
  const calls: string[] = []
  vi.stubGlobal('fetch', vi.fn(async (input: RequestInfo | URL) => {
    const url = String(input)
    calls.push(url)
    if (url.endsWith('/models')) {
      return new Response(JSON.stringify({ data: pricing }), { status: 200 })
    }
    if (url.endsWith('/credits')) {
      return new Response(JSON.stringify({ data: { ...credits } }), { status: 200 })
    }
    if (url.endsWith('/auth/key')) {
      return new Response(JSON.stringify({
        data: { label: 'test', usage: 1, limit: 1000, is_free_tier: false },
      }), { status: 200 })
    }
    return new Response('not found', { status: 404 })
  }))
  return { calls, credits }
}

async function loadComposition(): Promise<Context> {
  let rootDir = root
  if (rootDir === undefined) {
    rootDir = await mkdtemp(join(tmpdir(), 'dsh-openrouter-composition-'))
    root = rootDir
  }
  await writeFile(join(rootDir, '.credentials.yaml'), 'OPENROUTER_API_KEY: sk-openrouter-test\n', { mode: 0o600 })
  const settingsPath = join(rootDir, 'settings.yaml')
  await writeFile(settingsPath, '# test settings\n')
  await writeFile(join(rootDir, 'cordis.yml'), [
    "- name: '@deepseek-ai/dsh-session'",
    "- name: '@deepseek-ai/dsh-session-projection'",
    '- id: settings',
    "  name: '@deepseek-ai/dsh-settings-file'",
    '  config:',
    `    path: ${JSON.stringify(settingsPath)}`,
    '    debounceMs: 10',
    '- id: credentials',
    "  name: '@deepseek-ai/dsh-credentials-local'",
    '  config:',
    `    path: ${JSON.stringify(join(rootDir, '.credentials.yaml'))}`,
    '    debounceMs: 10',
    "- name: '@deepseek-ai/dsh-openrouter-usage'",
    '  config:',
    '    syncEnabled: false',
    '',
  ].join('\n'))

  const ctx = new Context()
  context = ctx
  ctx.baseUrl = pathToFileURL(rootDir).href + '/'
  await ctx.plugin(Loader)
  ctx.loader.builtins.include = Include
  const modules = new Map<string, unknown>([
    ['@deepseek-ai/dsh-session', SessionStore],
    ['@deepseek-ai/dsh-session-projection', SessionProjectionRegistry],
    ['@deepseek-ai/dsh-settings-file', FileSettingsProvider],
    ['@deepseek-ai/dsh-credentials-local', LocalCredentialProvider],
    ['@deepseek-ai/dsh-openrouter-usage', OpenRouterUsageGateway],
  ])
  ctx.loader.internal = {
    version: 'v2',
    async import(specifier: string) {
      if (!modules.has(specifier)) throw new Error(`unexpected Loader import: ${specifier}`)
      return modules.get(specifier)
    },
  } as unknown as NonNullable<typeof ctx.loader.internal>
  await ctx.loader.create({
    name: 'cordis:include',
    config: { path: pathToFileURL(join(rootDir, 'cordis.yml')).href },
  })
  await ctx.loader.await()
  return ctx
}

describe('openrouter-usage real composition', () => {
  it('resolves the key, fetches pricing, and prices a logged step through the composed registry', async () => {
    const openRouter = stubOpenRouter()
    const loaded = await loadComposition()

    // Give the gateway's refresh a moment to run against the mock.
    await vi.waitFor(() => {
      expect(openRouter.calls.some(url => url.endsWith('/models'))).toBe(true)
    }, { timeout: 5000 })

    const session = loaded.sessions.create()
    session.append('request/context', { provider: 'openrouter', model: 'deepseek/deepseek-chat' })
    session.append('turn/start', { turn: 1 })
    session.append('step/start', { turn: 1, step: 1 })
    session.append('assistant/chunk', {
      turn: 1,
      step: 1,
      chunk: { type: 'usage', usage: { inputTokens: 1_000, outputTokens: 200 } },
    })
    session.append('assistant/message', {
      turn: 1,
      step: 1,
      message: createMessage({
        role: 'assistant',
        content: [{ type: 'text', text: 'hi' }],
        source: { kind: 'model', provider: 'openrouter', model: 'deepseek/deepseek-chat' },
      }),
      usage: { inputTokens: 1_000, outputTokens: 200 },
    }, { surfaceOp: 'append', sourceEventSeqs: [session.events.length - 1] })
    session.append('step/end', { turn: 1, step: 1 })
    session.append('turn/end', { turn: 1, reason: { kind: 'completed' } })

    const cost = loaded.sessionProjections.snapshot(session).values.openRouterCost
    expect(cost).toMatchObject({
      totalUsd: 1000 * 1.4e-6 + 200 * 2.8e-6,
      pricedSteps: 1,
      unknownModelSteps: 0,
      currency: 'USD',
    })
  })

  it('serves the account balance snapshot through the Remote gateway', async () => {
    const openRouter = stubOpenRouter()
    const loaded = await loadComposition()

    await vi.waitFor(() => {
      expect(openRouter.calls.some(url => url.endsWith('/credits'))).toBe(true)
    }, { timeout: 5000 })

    const balance = loaded.openRouterUsage.snapshot()
    expect(balance.balanceUsd).toBe(41)
    expect(balance.label).toBe('test')
    expect(balance.currency).toBe('USD')
    expect(balance.updatedAt).not.toBeNull()
  })

  it('re-fetches the account on demand and serves the moved figure', async () => {
    const openRouter = stubOpenRouter()
    const loaded = await loadComposition()

    await vi.waitFor(() => {
      expect(openRouter.calls.some(url => url.endsWith('/credits'))).toBe(true)
    }, { timeout: 5000 })
    expect(loaded.openRouterUsage.snapshot().balanceUsd).toBe(41)

    openRouter.credits.total_usage = 12
    await expect(loaded.openRouterUsage.refresh()).resolves.toMatchObject({ balanceUsd: 30 })
    expect(loaded.openRouterUsage.snapshot().balanceUsd).toBe(30)
  })

  it('shares one in-flight fetch across concurrent on-demand refreshes', async () => {
    const openRouter = stubOpenRouter()
    const loaded = await loadComposition()

    await vi.waitFor(() => {
      expect(openRouter.calls.some(url => url.endsWith('/credits'))).toBe(true)
    }, { timeout: 5000 })
    const before = openRouter.calls.filter(url => url.endsWith('/credits')).length

    const [first, second] = await Promise.all([
      loaded.openRouterUsage.refresh(),
      loaded.openRouterUsage.refresh(),
    ])
    expect(first).toEqual(second)
    expect(openRouter.calls.filter(url => url.endsWith('/credits')).length).toBe(before + 1)

    // The shared promise is released once it settles, so a later click fetches again.
    await loaded.openRouterUsage.refresh()
    expect(openRouter.calls.filter(url => url.endsWith('/credits')).length).toBe(before + 2)
  })
})