/**
 * Step-handlers для stock-invariant-deep.
 *
 * Главный инвариант розничного учёта: для любого (ProductId, StoreId) сумма
 * StockMovement.Quantity точно равна materialized Stock.Quantity. Любое
 * расхождение = bug в Supply.Post / RetailSale.Post / Unpost — потеря товара
 * или ложные минусовые/завышенные остатки.
 *
 * Дополнительно проверяем что Serializable-транзакция RetailSale.Post
 * отбивает гонку: два кассира одновременно проводят чеки на один и тот же
 * остаток — должен пройти ровно один.
 */
import { login, makeClient } from '../lib/api.js'
import { psql } from '../lib/db.js'
import { generateEan13 } from '../lib/barcode.js'
import type { CheckResult, Step, Report } from '../lib/report.js'

const TS = Date.now()

interface Ctx {
  apiOnly: boolean
  superAdminToken?: string
  adminToken?: string
  productId?: string
  storeId?: string
  retailPointId?: string
  supplierId?: string
  currencyId?: string
  retailPriceTypeId?: string
  supplyA?: string
  supplyB?: string
  saleA?: string
  saleB?: string
}
interface StepCtx { ctx: Ctx; step: Step; report: Report }

function check(step: Step, c: CheckResult) { step.checks.push(c) }
function asString(x: unknown): string {
  if (x == null) return ''
  if (typeof x === 'string') return x
  try { return JSON.stringify(x).slice(0, 200) } catch { return String(x) }
}

async function ensureSuperAdmin(ctx: Ctx): Promise<string> {
  if (!ctx.superAdminToken) {
    const sa = await login('admin@food-market.local', 'Admin12345!')
    ctx.superAdminToken = sa.accessToken
  }
  return ctx.superAdminToken
}

function dbQty(productId: string, storeId: string): number {
  const out = psql(`SELECT "Quantity" FROM stocks
    WHERE "ProductId"='${productId}' AND "StoreId"='${storeId}'`).trim()
  return Number((out.split('\n')[0] || '0')) || 0
}

function dbMovementSum(productId: string, storeId: string): number {
  const out = psql(`SELECT COALESCE(SUM("Quantity"),0)::text FROM stock_movements
    WHERE "ProductId"='${productId}' AND "StoreId"='${storeId}'`).trim()
  return Number((out.split('\n')[0] || '0')) || 0
}

function dbMovementCount(productId: string, storeId: string): number {
  const out = psql(`SELECT count(*)::text FROM stock_movements
    WHERE "ProductId"='${productId}' AND "StoreId"='${storeId}'`).trim()
  return Number((out.split('\n')[0] || '0')) || 0
}

function assertInvariant(step: Step, productId: string, storeId: string, expectedQty: number) {
  const stock = dbQty(productId, storeId)
  const sum = dbMovementSum(productId, storeId)
  check(step, { kind: 'db', description: `Stock.Quantity == ${expectedQty}`,
    ok: stock === expectedQty, detail: `actual=${stock}` })
  check(step, { kind: 'db', description: 'Stock.Quantity == Σ StockMovement (invariant)',
    ok: stock === sum, detail: `stock=${stock} sum=${sum}` })
}

// ---------------------------------------------------------------------------

export async function step01_bootstrap({ ctx, step, report }: StepCtx) {
  const sa = await ensureSuperAdmin(ctx)
  const orgRes = await makeClient(sa).post('/api/super-admin/organizations', {
    org: {
      name: `Stock Inv ${TS}`, countryCode: 'KZ',
      bin: null, address: null, phone: null, email: null,
      defaultCurrencyId: null, accountOwnerUserId: null,
    },
    adminLastName: 'Stock', adminFirstName: 'Admin',
    adminEmail: `stock-inv-${TS}@example.kz`, adminPosition: null,
  })
  if (orgRes.status !== 200) { report.bug({ step: '01', severity: 'critical',
    title: 'Не удалось создать орг', detail: asString(orgRes.data) }); return }
  const adminSess = await login(orgRes.data.adminEmail, orgRes.data.adminTempPassword)
  ctx.adminToken = adminSess.accessToken
  const api = makeClient(ctx.adminToken)

  const units = await api.get('/api/catalog/units-of-measure')
  const unitId = units.data?.items?.[0]?.id ?? units.data?.[0]?.id
  const grps = await api.get('/api/catalog/product-groups?pageSize=10')
  let groupId = grps.data?.items?.[0]?.id
  if (!groupId) {
    const g = await api.post('/api/catalog/product-groups', { name: 'G', parentId: null })
    groupId = g.data?.id
  }
  const cur = await api.get('/api/catalog/currencies?pageSize=200')
  ctx.currencyId = cur.data?.items?.find((c: { code: string }) => c.code === 'KZT')?.id
  const pt = await api.get('/api/catalog/price-types')
  ctx.retailPriceTypeId = pt.data?.items?.find((p: { isRetail: boolean }) => p.isRetail)?.id
  const stores = await api.get('/api/catalog/stores?pageSize=10')
  ctx.storeId = stores.data?.items?.[0]?.id
  const rps = await api.get('/api/catalog/retail-points?pageSize=10')
  ctx.retailPointId = rps.data?.items?.[0]?.id

  const cp = await api.post('/api/catalog/counterparties', {
    name: `Inv Supplier ${TS}`, type: 1, bin: '987654321012', phone: '+77001112233',
  })
  ctx.supplierId = cp.data?.id

  const prod = await api.post('/api/catalog/products', {
    name: `Inv Product ${TS}`, unitOfMeasureId: unitId, productGroupId: groupId,
    vat: 12, vatEnabled: true,
    barcodes: [{ code: generateEan13(), type: 1, isPrimary: true }],
    prices: [{ priceTypeId: ctx.retailPriceTypeId, currencyId: ctx.currencyId, amount: 200 }],
  })
  ctx.productId = prod.data?.id
  check(step, { kind: 'api', description: 'Bootstrap product создан',
    ok: prod.status === 201, detail: ctx.productId ?? asString(prod.data) })

  // Стартовый стейт.
  assertInvariant(step, ctx.productId!, ctx.storeId!, 0)
}

async function postSupply(ctx: Ctx, quantity: number, unitPrice: number): Promise<string | undefined> {
  const api = makeClient(ctx.adminToken!)
  const sup = await api.post('/api/purchases/supplies', {
    storeId: ctx.storeId, supplierId: ctx.supplierId, currencyId: ctx.currencyId,
    date: new Date().toISOString(),
    lines: [{ productId: ctx.productId, quantity, unitPrice }],
  })
  if (sup.status !== 201) return undefined
  const p = await api.post(`/api/purchases/supplies/${sup.data.id}/post`)
  if (p.status >= 400) return undefined
  return sup.data.id
}

async function postSale(ctx: Ctx, quantity: number, unitPrice: number): Promise<string | undefined> {
  const api = makeClient(ctx.adminToken!)
  const sale = await api.post('/api/sales/retail', {
    storeId: ctx.storeId, retailPointId: ctx.retailPointId, currencyId: ctx.currencyId,
    date: new Date().toISOString(),
    lines: [{ productId: ctx.productId, quantity, unitPrice, vatPercent: 12 }],
    paidCash: quantity * unitPrice, paidCard: 0,
  })
  if (sale.status !== 201) return undefined
  const p = await api.post(`/api/sales/retail/${sale.data.id}/post`)
  if (p.status >= 400) return undefined
  return sale.data.id
}

export async function step02_supply_a_qty_20({ ctx, step, report }: StepCtx) {
  if (!ctx.productId) { step.status = 'skip'; return }
  ctx.supplyA = await postSupply(ctx, 20, 100)
  check(step, { kind: 'api', description: 'Supply A qty=20 проведена', ok: !!ctx.supplyA })
  assertInvariant(step, ctx.productId, ctx.storeId!, 20)
}

export async function step03_sale_a_qty_5({ ctx, step }: StepCtx) {
  if (!ctx.productId) { step.status = 'skip'; return }
  ctx.saleA = await postSale(ctx, 5, 200)
  check(step, { kind: 'api', description: 'Sale A qty=5 проведена', ok: !!ctx.saleA })
  assertInvariant(step, ctx.productId, ctx.storeId!, 15)
}

export async function step04_supply_b_qty_10({ ctx, step }: StepCtx) {
  if (!ctx.productId) { step.status = 'skip'; return }
  ctx.supplyB = await postSupply(ctx, 10, 120)
  check(step, { kind: 'api', description: 'Supply B qty=10 проведена', ok: !!ctx.supplyB })
  assertInvariant(step, ctx.productId, ctx.storeId!, 25)
}

export async function step05_sale_b_qty_8({ ctx, step }: StepCtx) {
  if (!ctx.productId) { step.status = 'skip'; return }
  ctx.saleB = await postSale(ctx, 8, 200)
  check(step, { kind: 'api', description: 'Sale B qty=8 проведена', ok: !!ctx.saleB })
  assertInvariant(step, ctx.productId, ctx.storeId!, 17)
}

export async function step06_unpost_sale_a({ ctx, step }: StepCtx) {
  if (!ctx.saleA) { step.status = 'skip'; return }
  const api = makeClient(ctx.adminToken!)
  const r = await api.post(`/api/sales/retail/${ctx.saleA}/unpost`)
  check(step, { kind: 'api', description: 'Unpost Sale A → 200/204',
    ok: r.status === 200 || r.status === 204, detail: `status=${r.status}` })
  assertInvariant(step, ctx.productId!, ctx.storeId!, 22)
}

export async function step07_repost_sale_a({ ctx, step }: StepCtx) {
  if (!ctx.saleA) { step.status = 'skip'; return }
  const api = makeClient(ctx.adminToken!)
  const r = await api.post(`/api/sales/retail/${ctx.saleA}/post`)
  check(step, { kind: 'api', description: 'Re-post Sale A → 200/204',
    ok: r.status === 200 || r.status === 204, detail: `status=${r.status}` })
  assertInvariant(step, ctx.productId!, ctx.storeId!, 17)
}

export async function step08_movement_count_correct({ ctx, step, report }: StepCtx) {
  if (!ctx.productId) { step.status = 'skip'; return }
  const cnt = dbMovementCount(ctx.productId, ctx.storeId!)
  // 2 supply + 2 sale + 1 reverse(unpost-sale-A) + 1 re-post sale-A = 6 строк.
  // Реализация может писать дополнительные movement'ы (например, при unpost
  // sale-A пишется reversal с положительным qty; при re-post — обычный negative).
  // Минимум 4 (по одному на каждый posted документ) и не больше 8.
  check(step, { kind: 'db', description: 'StockMovement содержит как минимум 4 строки',
    ok: cnt >= 4, detail: `count=${cnt}` })
  check(step, { kind: 'db', description: 'StockMovement не более 8 строк (нет лишних дублей)',
    ok: cnt <= 8, detail: `count=${cnt}` })
  if (cnt > 8) report.gap(`StockMovement аномально большой: ${cnt} строк после 4 documents + 1 unpost + 1 re-post.`)
}

export async function step09_concurrent_sales_serialized({ ctx, step, report }: StepCtx) {
  if (!ctx.productId) { step.status = 'skip'; return }
  // Сейчас остаток 17. Создаём два Draft чека по qty=10 каждый, проводим
  // ОДНОВРЕМЕННО — один должен 200, второй 409 (Serializable).
  const api = makeClient(ctx.adminToken!)
  const mk = async () => {
    const sale = await api.post('/api/sales/retail', {
      storeId: ctx.storeId, retailPointId: ctx.retailPointId, currencyId: ctx.currencyId,
      date: new Date().toISOString(),
      lines: [{ productId: ctx.productId, quantity: 10, unitPrice: 200, vatPercent: 12 }],
      paidCash: 2000, paidCard: 0,
    })
    return sale.data?.id as string
  }
  const a = await mk()
  const b = await mk()
  check(step, { kind: 'api', description: 'Два Draft созданы', ok: !!a && !!b })

  const [r1, r2] = await Promise.all([
    api.post(`/api/sales/retail/${a}/post`),
    api.post(`/api/sales/retail/${b}/post`),
  ])
  const statuses = [r1.status, r2.status].sort()
  // Ожидаем: один 200/204, второй 409 (или 500 если Serializable retry не настроен).
  const success = statuses.filter(s => s >= 200 && s < 300).length
  const fail = statuses.filter(s => s >= 400).length
  check(step, { kind: 'api', description: 'Ровно один post 2xx, второй 4xx (5xx)',
    ok: success === 1 && fail === 1, detail: `statuses=${statuses.join(',')}` })

  // Stock не должен уйти в минус ни в каком случае.
  const stock = dbQty(ctx.productId, ctx.storeId!)
  check(step, { kind: 'db', description: 'Stock >= 0 (не минус из-за гонки)',
    ok: stock >= 0, detail: `stock=${stock}` })
  if (stock < 0) report.bug({ step: '09', severity: 'critical',
    title: 'Конкурентный RetailSale.Post привёл к отрицательному Stock',
    detail: `stock=${stock}. Serializable-транзакция не сработала или dropped.` })
  if (success === 2) report.bug({ step: '09', severity: 'critical',
    title: 'Оба POST /post прошли при остатке < ΣQty',
    detail: 'Гонка не отбита — потеря товара.' })
  // Инвариант после гонки тоже сохраняется.
  const sum = dbMovementSum(ctx.productId, ctx.storeId!)
  check(step, { kind: 'db', description: 'Stock == Σ Movement после гонки',
    ok: stock === sum, detail: `stock=${stock} sum=${sum}` })
}

export async function step10_final_invariant({ ctx, step }: StepCtx) {
  if (!ctx.productId) { step.status = 'skip'; return }
  const stock = dbQty(ctx.productId, ctx.storeId!)
  const sum = dbMovementSum(ctx.productId, ctx.storeId!)
  check(step, { kind: 'db', description: 'Финальный invariant Stock == Σ Movement',
    ok: stock === sum, detail: `stock=${stock} sum=${sum}` })
}