package assignment

import (
	"testing"
	"time"
)

// The per-miler concurrent-stop cap.
//
// This is the knob that now decides how much one rider carries, because
// eligibility no longer stops at the first order. It is read per call so it
// can be changed without a redeploy — and a typo must never uncap the fleet.
func TestMaxActiveBookings(t *testing.T) {
	cases := []struct {
		env  string
		want int64
		why  string
	}{
		{"", defaultMaxActive, "unset falls back to the default"},
		{"10", 10, "a plain number is honoured"},
		{" 8 ", 8, "surrounding whitespace is tolerated"},
		{"1", 1, "one stop at a time is a legitimate policy"},
		{"0", defaultMaxActive, "zero would assign to nobody — treated as unset, not as a cap"},
		{"-4", defaultMaxActive, "negative is meaningless here"},
		{"lots", defaultMaxActive, "a typo must not uncap the fleet"},
		{"3.5", defaultMaxActive, "not an integer"},
	}

	for _, tc := range cases {
		t.Setenv("MILER_MAX_ACTIVE_BOOKINGS", tc.env)
		if got := maxActiveBookings(); got != tc.want {
			t.Errorf("MILER_MAX_ACTIVE_BOOKINGS=%q gave %d, want %d (%s)", tc.env, got, tc.want, tc.why)
		}
	}
}

// The cap counts only stops assigned since midnight India time, so an order
// left open yesterday or last month no longer blocks a working rider.
func TestStartOfISTDay(t *testing.T) {
	ist := time.FixedZone("IST", 5*3600+30*60)
	cases := []struct{ now, want time.Time }{
		// 11:43 IST on 6 Oct -> 00:00 IST 6 Oct
		{time.Date(2026, 10, 6, 11, 43, 0, 0, ist), time.Date(2026, 10, 6, 0, 0, 0, 0, ist)},
		// 20:00 UTC on 5 Oct is already 01:30 on 6 Oct in India
		{time.Date(2026, 10, 5, 20, 0, 0, 0, time.UTC), time.Date(2026, 10, 6, 0, 0, 0, 0, ist)},
		// 18:29 UTC on 5 Oct is still 23:59 on 5 Oct in India
		{time.Date(2026, 10, 5, 18, 29, 0, 0, time.UTC), time.Date(2026, 10, 5, 0, 0, 0, 0, ist)},
	}
	for _, c := range cases {
		if got := startOfISTDay(c.now); !got.Equal(c.want) {
			t.Errorf("startOfISTDay(%v) = %v, want %v", c.now, got, c.want)
		}
	}
}