package seeder_test

import (
	"testing"
	"time"

	"github.com/krow/krow-backend/go-api/internal/seeder"
)

// The shift generator is a port of src/api/attendanceSeed.js. These tests pin
// the distribution that module's own documentation describes, so a drift in the
// port shows up as a failing assertion rather than as quietly different
// attendance figures.

func shiftsFor(anchor time.Time, email string) []map[string]any {
	var out []map[string]any
	for _, r := range seeder.BuildShifts(anchor) {
		if r["worker_email"] == email {
			out = append(out, r)
		}
	}
	return out
}

func TestShiftDistributionMatchesSource(t *testing.T) {
	anchor := time.Date(2026, 8, 21, 12, 0, 0, 0, time.Local)
	all := seeder.BuildShifts(anchor)

	counts := map[string]int{}
	for _, r := range all {
		counts[r["status"].(string)]++
	}

	// Marcus alone supplies the attendance anomaly: two absences, one no-show
	// and three late arrivals in the recent window, plus one older late.
	if counts["absent"] != 2 {
		t.Errorf("absent = %d, want 2", counts["absent"])
	}
	if counts["no_show"] != 1 {
		t.Errorf("no_show = %d, want 1", counts["no_show"])
	}
	// Marcus i=1,5,9,26 plus Marco i=14.
	if counts["late"] != 5 {
		t.Errorf("late = %d, want 5", counts["late"])
	}
	if counts["present"] == 0 {
		t.Error("no present shifts generated")
	}
}

func TestShiftRosterIsThreePeople(t *testing.T) {
	anchor := time.Date(2026, 8, 21, 12, 0, 0, 0, time.Local)
	emails := map[string]bool{}
	for _, r := range seeder.BuildShifts(anchor) {
		emails[r["worker_email"].(string)] = true
	}
	if len(emails) != 3 {
		t.Fatalf("roster has %d people, want 3 (one per hire)", len(emails))
	}
}

// A missed shift is zero hours worked, not a short one — and the schema's
// shift_records_absence_has_no_hours constraint depends on it.
func TestAbsencesHaveNoHours(t *testing.T) {
	anchor := time.Date(2026, 8, 21, 12, 0, 0, 0, time.Local)
	for _, r := range seeder.BuildShifts(anchor) {
		status := r["status"].(string)
		if status != "absent" && status != "no_show" {
			continue
		}
		if r["actual_hours"].(float64) != 0 {
			t.Errorf("%s: %s shift has actual_hours %v", r["id"], status, r["actual_hours"])
		}
		if r["minutes_late"].(int) != 0 {
			t.Errorf("%s: %s shift has minutes_late %v", r["id"], status, r["minutes_late"])
		}
		if r["actual_start"] != nil || r["actual_end"] != nil {
			t.Errorf("%s: %s shift has actual timestamps", r["id"], status)
		}
	}
}

// Antoine's overtime climbs week on week — a trend rather than a spike. It is
// the overtime anomaly the analytics are shaped to surface.
func TestAntoineOvertimeClimbs(t *testing.T) {
	anchor := time.Date(2026, 8, 21, 12, 0, 0, 0, time.Local)
	shifts := shiftsFor(anchor, "antoine.dubois@email.com")
	if len(shifts) == 0 {
		t.Fatal("no shifts generated for Antoine")
	}

	// BuildShifts returns most-recent-first, so recent overtime should exceed
	// the overtime from the far end of the window.
	var recent, older float64
	for i, r := range shifts {
		ot := r["overtime_hours"].(float64)
		if i < 10 {
			recent += ot
		}
		if i >= len(shifts)-10 {
			older += ot
		}
	}
	if recent <= older {
		t.Errorf("overtime is not climbing: recent 10 = %.1fh, oldest 10 = %.1fh", recent, older)
	}
}

// created_date is the instant the shift was worked. dataResolver windows every
// collection on it, so a shift dated anywhere else would vanish from every
// period reading.
func TestShiftCreatedDateIsTheShiftInstant(t *testing.T) {
	anchor := time.Date(2026, 8, 21, 12, 0, 0, 0, time.Local)
	for _, r := range seeder.BuildShifts(anchor) {
		if r["created_date"] != r["scheduled_start"] {
			t.Fatalf("%s: created_date %v is not the scheduled start %v",
				r["id"], r["created_date"], r["scheduled_start"])
		}
	}
}

// The window rolls forward with the anchor: shifts must stay recent relative to
// whenever the seeder runs, which is the whole reason this is a port rather
// than a frozen snapshot.
func TestShiftWindowFollowsTheAnchor(t *testing.T) {
	early := seeder.BuildShifts(time.Date(2026, 3, 1, 12, 0, 0, 0, time.Local))
	late := seeder.BuildShifts(time.Date(2026, 8, 21, 12, 0, 0, 0, time.Local))
	if early[0]["created_date"] == late[0]["created_date"] {
		t.Fatal("shift dates did not move with the anchor")
	}
	if got := late[0]["created_date"].(string)[:4]; got != "2026" {
		t.Errorf("most recent shift is dated %s", got)
	}
}