import { describe, it, expect } from 'vitest'
import { openDb } from '../src/db'
import { createClient } from '../src/repos-clients'
import { upsertAwsUsage, getAwsUsage, listAwsUsage, costRanking, awsCostForClient, previousMonth } from '../src/repos-aws'

function setup() {
  const db = openDb(':memory:')
  const a = createClient(db, 'u1', { name: 'Acme', code: 'ACME', stateCode: '32' })
  const b = createClient(db, 'u1', { name: 'Bolt', code: 'BOLT', stateCode: '29' })
  return { db, a, b }
}

describe('aws usage repo', () => {
  it('upserts and merges a (client, month) row without clobbering the other source', () => {
    const { db, a } = setup()
    upsertAwsUsage(db, 'u1', { clientId: a.id, month: '2026-06', costPaise: 5_000_00, source: 'auto' })
    upsertAwsUsage(db, 'u1', { clientId: a.id, month: '2026-06', storageGb: 42.5, source: 'manual' }) // merges
    const row = getAwsUsage(db, a.id, '2026-06')!
    expect(row.costPaise).toBe(5_000_00) // auto cost preserved
    expect(row.storageGb).toBe(42.5)     // manual storage applied
    expect(db.prepare(`SELECT COUNT(*) AS n FROM aws_usage WHERE client_id=?`).get(a.id)).toMatchObject({ n: 1 })
    const audits = db.prepare(`SELECT action FROM audit_log WHERE entity='aws_usage'`).all()
    expect(audits.length).toBe(2) // create + update
  })
  it('lists newest month first, capped', () => {
    const { db, a } = setup()
    for (const m of ['2026-04', '2026-05', '2026-06']) upsertAwsUsage(db, 'u1', { clientId: a.id, month: m, costPaise: 100 })
    expect(listAwsUsage(db, a.id, 2).map((r) => r.month)).toEqual(['2026-06', '2026-05'])
  })
  it('rejects a bad month', () => {
    const { db, a } = setup()
    expect(() => upsertAwsUsage(db, 'u1', { clientId: a.id, month: '2026/06', costPaise: 1 })).toThrow(/month/i)
  })
  it('ranks clients by cost with share in basis points', () => {
    const { db, a, b } = setup()
    upsertAwsUsage(db, 'u1', { clientId: a.id, month: '2026-06', costPaise: 7_500_00 })
    upsertAwsUsage(db, 'u1', { clientId: b.id, month: '2026-06', costPaise: 2_500_00 })
    const r = costRanking(db, '2026-06')
    expect(r.total).toBe(10_000_00)
    expect(r.rows.map((x) => x.clientId)).toEqual([a.id, b.id]) // Acme first (higher cost)
    expect(r.rows[0]!.sharePctBp).toBe(7500) // 75.00%
    expect(r.rows[1]!.sharePctBp).toBe(2500)
  })
  it('sums a client cost over a month range and derives the previous month', () => {
    const { db, a } = setup()
    upsertAwsUsage(db, 'u1', { clientId: a.id, month: '2026-05', costPaise: 100 })
    upsertAwsUsage(db, 'u1', { clientId: a.id, month: '2026-06', costPaise: 200 })
    upsertAwsUsage(db, 'u1', { clientId: a.id, month: '2026-07', costPaise: 400 })
    expect(awsCostForClient(db, a.id, '2026-05-01', '2026-06-30')).toBe(300)
    expect(awsCostForClient(db, a.id)).toBe(700)
    expect(previousMonth('2026-07-10')).toBe('2026-06')
    expect(previousMonth('2026-01-05')).toBe('2025-12') // year rollover
  })
})