import { describe, it, expect, beforeEach, vi, afterEach } from 'vitest'
import { StormStore, STORM_REFRESH_MS } from '../../../src/lib/stores/storm.svelte.js'
import { app } from '../../../src/lib/stores/app.svelte.js'
import { clearStormCache } from '../../../src/lib/api/storm.js'

// ---- fixtures ------------------------------------------------------------

const box = (w, s, e, n) => [[[w, s], [e, s], [e, n], [w, n], [w, s]]]

const catFc = (label) => ({
  type: 'FeatureCollection',
  features: [{
    type: 'Feature',
    properties: { LABEL: label, ISSUE_ISO: '2026-10-17T16:14:00+00:00' },
    geometry: { type: 'Polygon', coordinates: box(-100, 30, -90, 40) },
  }],
})

const probFc = (label) => ({
  type: 'FeatureCollection',
  features: [{
    type: 'Feature',
    properties: { LABEL: label },
    geometry: { type: 'Polygon', coordinates: box(-100, 30, -90, 40) },
  }],
})

const alertsFc = (features) => ({ type: 'FeatureCollection', features })

const alertFeature = (props) => ({
  type: 'Feature',
  properties: { status: 'Actual', messageType: 'Alert', ...props },
  geometry: { type: 'Polygon', coordinates: box(-97, 35, -96, 36) },
})

const lsrFc = (features) => ({ type: 'FeatureCollection', features })

const lsr = (city, lon, lat) => ({
  type: 'Feature',
  properties: {
    typetext: 'HAIL', city, county: 'X', state: 'OK', source: 'Trained Spotter',
    valid: '2026-10-17T11:00:00Z', magnitude: '1.75', remark: 'quarter size',
  },
  geometry: { type: 'Point', coordinates: [lon, lat] },
})

// ---- fetch stub ----------------------------------------------------------

let calls
let overrides

function installFetch() {
  calls = []
  overrides = {}
  globalThis.fetch = vi.fn(async (url) => {
    const u = String(url)
    calls.push(u)
    for (const [match, handler] of Object.entries(overrides)) {
      if (u.includes(match)) return handler(u)
    }
    const json = (body) => ({ ok: true, status: 200, json: async () => body })
    if (u.includes('api.weather.gov/alerts/active')) return json(alertsFc([]))
    if (u.includes('day1otlk_cat')) return json(catFc('SLGT'))
    if (u.includes('day2otlk_cat')) return json(catFc('MRGL'))
    if (u.includes('day3otlk_cat')) return json(catFc('TSTM'))
    if (u.includes('day1otlk_torn')) return json(probFc('5%'))
    if (u.includes('day1otlk_wind')) return json(probFc('15%'))
    if (u.includes('day1otlk_hail')) return json(probFc('30%'))
    if (u.includes('mesonet.agron.iastate.edu')) return json(lsrFc([lsr('Near', -95.82, 36.36)]))
    return { ok: false, status: 404, json: async () => ({}) }
  })
}

function setLocation(lat, lon, name = 'Test') {
  app.locations = [{ id: 'loc-1', name, lat, lon, isCurrent: true }]
  app.selectedLocationId = 'loc-1'
}

// ---- tests ---------------------------------------------------------------

describe('StormStore', () => {
  let store

  beforeEach(() => {
    clearStormCache()
    installFetch()
    store = new StormStore()
    setLocation(36.3567, -95.8146, 'Home')
  })

  afterEach(() => {
    store.stop()
    vi.restoreAllMocks()
  })

  it('loads alerts, outlook and reports for the selected location', async () => {
    overrides['api.weather.gov/alerts/active'] = async () => ({
      ok: true, status: 200,
      json: async () => alertsFc([
        alertFeature({ id: 't1', event: 'Tornado Warning', severity: 'Extreme', ends: '2026-10-17T19:00:00Z' }),
      ]),
    })

    await store.watch({ force: true })

    expect(store.alerts).toHaveLength(1)
    expect(store.alerts[0].event).toBe('Tornado Warning')
    expect(store.banner?.id).toBe('t1')
    expect(store.outlook.day1.key).toBe('SLGT')
    expect(store.outlook.day2.key).toBe('MRGL')
    expect(store.outlook.probabilities).toEqual({ tornado: 5, wind: 15, hail: 30 })
    expect(store.reports).toHaveLength(1)
    expect(store.reports[0].city).toBe('Near')
    expect(store.loading).toBe(false)
    expect(store.updatedAt).toBeGreaterThan(0)
    expect(store.alertCount).toBe(1)
  })

  it('serves fresh data from the store/HTTP cache until it expires', async () => {
    await store.watch({ force: true })
    const firstCount = calls.length
    expect(firstCount).toBeGreaterThan(0)

    await store.watch() // store-level: data for this location is fresh
    expect(calls.length).toBe(firstCount)

    await store.watch({ force: true }) // HTTP cache still warm
    expect(calls.length).toBe(firstCount)

    clearStormCache() // simulate the TTLs expiring
    await store.watch({ force: true })
    expect(calls.length).toBeGreaterThan(firstCount)
  })

  it('refetches when the selected location changes', async () => {
    await store.watch({ force: true })
    const firstCount = calls.length

    setLocation(27.2, -82.3, 'Elsewhere')
    await store.watch()

    const fresh = calls.slice(firstCount)
    expect(fresh.length).toBeGreaterThan(0)
    expect(fresh.some((u) => u.includes('36.3567'))).toBe(false) // old point not refetched
    expect(fresh.some((u) => u.includes('27.2'))).toBe(true) // new point queried
  })

  it('keeps the other feeds when one request fails', async () => {
    overrides['mesonet.agron.iastate.edu'] = async () => ({
      ok: false, status: 503, json: async () => ({}),
    })

    await store.watch({ force: true })

    expect(store.reports).toEqual([])
    expect(store.outlook.day1.key).toBe('SLGT')
    expect(store.error).toMatch(/reports/)
  })

  it('skips SPC/LSR requests outside the US and clears the outlook', async () => {
    setLocation(51.5, -0.12, 'London')
    await store.watch({ force: true })

    expect(store.hasUsCoverage).toBe(false)
    expect(store.outlook).toBeNull()
    expect(store.reports).toEqual([])
    expect(calls.some((u) => u.includes('spc.noaa.gov'))).toBe(false)
    expect(calls.some((u) => u.includes('api.weather.gov'))).toBe(true)
  })

  it('reset() drops data and the location key', async () => {
    await store.watch({ force: true })
    store.reset()
    expect(store.alerts).toEqual([])
    expect(store.outlook).toBeNull()
    expect(store.reports).toEqual([])
    expect(store.updatedAt).toBe(0)
  })

  it('start() schedules a refresh at the documented interval', () => {
    vi.useFakeTimers()
    try {
      const spy = vi.spyOn(store, 'watch').mockResolvedValue()
      store.start()
      store.start() // idempotent
      vi.advanceTimersByTime(STORM_REFRESH_MS + 10)
      expect(spy).toHaveBeenCalledTimes(1)
      expect(spy).toHaveBeenCalledWith({ force: true })
      store.stop()
    } finally {
      vi.useRealTimers()
    }
  })
})