feat(maps): draw every travel day's route at once, with the trip total

Extract the day route builder out of useRouteCalculation into a pure module and
aggregate it over the whole trip: one map with every day's route, each day in its
own colour, the mode per stage and the trip's total distance. Straight lines first,
roads as they answer; a refused leg keeps its line and adds no distance.

Give the floating map controls one shared drop shadow while adding the toggle, so
the new pill and the base-layer switcher stand off the tiles the way the locate
button always has. Document the control in wiki/Map-Features.md.

Addresses #1736

client/src/components/Map/useTripRouteOverview.test.ts

@@ -0,0 +1,137 @@
+import { renderHook, waitFor } from '@testing-library/react'
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+import { TRACK_COLORS } from '@trek/shared'
+import { useTripRouteOverview } from './useTripRouteOverview'
+import { buildAssignment, buildDay, buildPlace } from '../../../tests/helpers/factories'
+import type { AssignmentsMap, RouteSegment } from '../../types'
+
+vi.mock('./RouteCalculator', async (importActual) => {
+  const actual = await importActual<typeof import('./RouteCalculator')>()
+  return { ...actual, calculateRouteWithLegs: vi.fn() }
+})
+
+const { calculateRouteWithLegs } = await import('./RouteCalculator')
+
+const leg = (distance: number, duration: number): RouteSegment => ({
+  mid: [0, 0], from: [0, 0], to: [0, 0],
+  distance, duration,
+  distanceText: `${Math.round(distance / 1000)} km`,
+  durationText: '1 h', walkingText: '5 h', drivingText: '1 h',
+})
+
+const at = (lat: number, lng: number, order: number, dayId: number, extra: Record<string, unknown> = {}) =>
+  buildAssignment({ day_id: dayId, order_index: order, place: buildPlace({ lat, lng }), ...extra })
+
+const DAYS = [buildDay({ id: 1, day_number: 1 }), buildDay({ id: 2, day_number: 2 })]
+const ASSIGNMENTS: AssignmentsMap = {
+  '1': [at(48.86, 2.35, 0, 1), at(48.88, 2.36, 1, 1)],
+  '2': [at(45.76, 4.83, 0, 2), at(45.78, 4.85, 1, 2)],
+}
+
+const render = (enabled = true, assignments: AssignmentsMap = ASSIGNMENTS, days = DAYS) =>
+  renderHook(
+    ({ assignments: a }: { assignments: AssignmentsMap }) =>
+      useTripRouteOverview(7, days, a, [], [], 'driving', enabled),
+    { initialProps: { assignments } },
+  )
+
+beforeEach(() => {
+  vi.mocked(calculateRouteWithLegs).mockReset()
+  vi.mocked(calculateRouteWithLegs).mockResolvedValue({
+    coordinates: [[48.86, 2.35], [48.87, 2.355], [48.88, 2.36]],
+    distance: 12000, duration: 900,
+    legs: [leg(12000, 900)],
+  })
+})
+
+describe('useTripRouteOverview', () => {
+  it('FE-MAP-TRO-001: does nothing at all until it is switched on', () => {
+    const { result } = render(false)
+
+    expect(result.current.days).toEqual([])
+    expect(result.current.totalDistance).toBe(0)
+    expect(result.current.loading).toBe(false)
+    expect(calculateRouteWithLegs).not.toHaveBeenCalled()
+  })
+
+  it('FE-MAP-TRO-002: sums every day into the trip total', async () => {
+    const { result } = render()
+
+    await waitFor(() => expect(result.current.loading).toBe(false))
+    expect(result.current.days).toHaveLength(2)
+    expect(result.current.days.map(d => d.distance)).toEqual([12000, 12000])
+    expect(result.current.totalDistance).toBe(24000)
+    expect(result.current.totalDuration).toBe(1800)
+  })
+
+  it('FE-MAP-TRO-003: gives each day its own colour from the map palette', async () => {
+    const { result } = render()
+
+    await waitFor(() => expect(result.current.loading).toBe(false))
+    const colors = result.current.days.map(d => d.color)
+    expect(colors[0]).toBe(TRACK_COLORS[1])
+    expect(colors[1]).toBe(TRACK_COLORS[2])
+    // Every drawn line is labelled with the colour of the day it belongs to.
+    expect(result.current.lineColors).toHaveLength(result.current.lines.length)
+    expect(new Set(result.current.lineColors).size).toBe(2)
+  })
+
+  it('FE-MAP-TRO-004: reports the modes each day is travelled in', async () => {
+    const { result } = render(true, {
+      '1': [at(48.86, 2.35, 0, 1, { leg_transport_mode: 'walking' }), at(48.88, 2.36, 1, 1)],
+      '2': ASSIGNMENTS['2'],
+    })
+
+    await waitFor(() => expect(result.current.loading).toBe(false))
+    expect(result.current.days[0].modes).toEqual(['walking'])
+    expect(result.current.days[1].modes).toEqual(['driving'])
+    expect(result.current.days[0].segments[0].mode).toBe('walking')
+  })
+
+  it('FE-MAP-TRO-005: draws straight lines first and keeps them when routing refuses', async () => {
+    vi.mocked(calculateRouteWithLegs).mockRejectedValue(new Error('429'))
+    const { result } = render()
+
+    await waitFor(() => expect(result.current.loading).toBe(false))
+    // The shape of the trip is still on the map...
+    expect(result.current.lines).toHaveLength(2)
+    expect(result.current.lines[0]).toEqual([[48.86, 2.35], [48.88, 2.36]])
+    // ...but a leg that never answered contributes no distance.
+    expect(result.current.totalDistance).toBe(0)
+  })
+
+  it('FE-MAP-TRO-006: a day with nothing to drive is left out', async () => {
+    const { result } = render(true, { '1': ASSIGNMENTS['1'], '2': [at(45.76, 4.83, 0, 2)] })
+
+    await waitFor(() => expect(result.current.loading).toBe(false))
+    expect(result.current.days.map(d => d.dayId)).toEqual([1])
+  })
+
+  it('FE-MAP-TRO-007: frames the whole trip, not one day of it', async () => {
+    const { result } = render()
+
+    await waitFor(() => expect(result.current.loading).toBe(false))
+    expect(result.current.focusPoints.length).toBe(result.current.lines.flat().length)
+    expect(result.current.focusPoints.length).toBeGreaterThan(2)
+  })
+
+  it('FE-MAP-TRO-008: renaming a place does not re-route the trip', async () => {
+    const { result, rerender } = render()
+    await waitFor(() => expect(result.current.loading).toBe(false))
+    const calls = vi.mocked(calculateRouteWithLegs).mock.calls.length
+
+    expect(calls).toBeGreaterThan(0)
+
+    // A new object identity with the same geometry: the plan memo re-runs, the
+    // routing round must not.
+    rerender({
+      assignments: {
+        ...ASSIGNMENTS,
+        '1': ASSIGNMENTS['1'].map(a => ({ ...a, place: { ...a.place, name: 'Renamed' } })),
+      },
+    })
+
+    await waitFor(() => expect(result.current.loading).toBe(false))
+    expect(vi.mocked(calculateRouteWithLegs).mock.calls.length).toBe(calls)
+  })
+})