package service

import (
	"context"
	"errors"
	"testing"

	"gitea.stevedudenhoeffer.com/steve/pansy/internal/domain"
)

func TestNamedRegion(t *testing.T) {
	o := &domain.GardenObject{WidthCM: 200, HeightCM: 100} // hw=100, hh=50
	cases := []struct {
		name                   string
		minX, minY, maxX, maxY float64
	}{
		{"all", -100, -50, 100, 50},
		{"north", -100, -50, 100, 0},
		{"top half", -100, -50, 100, 0},
		{"south", -100, 0, 100, 50},
		{"bottom", -100, 0, 100, 50},
		{"east", 0, -50, 100, 50},
		{"right half", 0, -50, 100, 50},
		{"west", -100, -50, 0, 50},
		{"nw", -100, -50, 0, 0},
		{"NE corner", 0, -50, 100, 0},
		{"northeast", 0, -50, 100, 0},
		{"sw", -100, 0, 0, 50},
		{"se corner", 0, 0, 100, 50},
	}
	for _, c := range cases {
		r, err := NamedRegion(o, c.name)
		if err != nil {
			t.Errorf("%q: unexpected error %v", c.name, err)
			continue
		}
		if r.MinX != c.minX || r.MinY != c.minY || r.MaxX != c.maxX || r.MaxY != c.maxY {
			t.Errorf("%q = [%v,%v,%v,%v], want [%v,%v,%v,%v]", c.name, r.MinX, r.MinY, r.MaxX, r.MaxY, c.minX, c.minY, c.maxX, c.maxY)
		}
	}
	if _, err := NamedRegion(o, "middle-ish"); !errors.Is(err, domain.ErrInvalidInput) {
		t.Errorf("unknown region err = %v, want ErrInvalidInput", err)
	}
	if _, err := NamedRegion(o, ""); !errors.Is(err, domain.ErrInvalidInput) {
		t.Errorf("empty region err = %v, want ErrInvalidInput", err)
	}
	if _, err := NamedRegion(nil, "all"); !errors.Is(err, domain.ErrInvalidInput) {
		t.Errorf("nil object err = %v, want ErrInvalidInput", err)
	}
}

func TestFillRegionCappedForHugeArea(t *testing.T) {
	ctx := context.Background()
	s := newTestService(t, openConfig())
	owner := seedUser(t, s, "a@example.com")
	g, _ := s.CreateGarden(ctx, owner, GardenInput{Name: "Huge", WidthCM: 8000, HeightCM: 8000})
	bed := seedFillBed(t, s, owner, g.ID, 6000, 6000) // ~46k lattice points at radius 15 → over the cap
	plant := seedOwnPlant(t, s, owner, 10)
	region, _ := NamedRegion(bed, "all")
	if _, err := s.FillRegion(ctx, owner, bed.ID, region, plant.ID, nil); !errors.Is(err, domain.ErrInvalidInput) {
		t.Errorf("oversized fill err = %v, want ErrInvalidInput (over maxFillPlops)", err)
	}
}

func TestDefaultPlopRadius(t *testing.T) {
	if got := defaultPlopRadius(4); got != 15 { // 1.5*4=6 → floored to 15
		t.Errorf("radius(4) = %v, want 15", got)
	}
	if got := defaultPlopRadius(20); got != 30 { // 1.5*20
		t.Errorf("radius(20) = %v, want 30", got)
	}
}

// seedFillBed makes a plantable bed of the given size centered in a big garden.
func seedFillBed(t *testing.T, s *Service, owner, gardenID int64, w, h float64) *domain.GardenObject {
	t.Helper()
	o, err := s.CreateObject(context.Background(), owner, gardenID, ObjectInput{
		Kind: domain.KindBed, XCM: 1000, YCM: 1000, WidthCM: w, HeightCM: h,
	})
	if err != nil {
		t.Fatalf("seed bed %vx%v: %v", w, h, err)
	}
	return o
}

func TestFillRegionDeterministicPacking(t *testing.T) {
	ctx := context.Background()
	s := newTestService(t, openConfig())
	owner := seedUser(t, s, "a@example.com")
	g, err := s.CreateGarden(ctx, owner, GardenInput{Name: "Big", WidthCM: 2000, HeightCM: 2000})
	if err != nil {
		t.Fatalf("garden: %v", err)
	}
	bed := seedFillBed(t, s, owner, g.ID, 60, 60) // hw=hh=30
	plant := seedOwnPlant(t, s, owner, 10)        // radius = max(15,15) = 15

	region, _ := NamedRegion(bed, "all")
	created, err := s.FillRegion(ctx, owner, bed.ID, region, plant.ID, nil)
	if err != nil {
		t.Fatalf("FillRegion: %v", err)
	}
	// Hex lattice on [-30,30]² at pitch 30, rows ~26 apart → 4 plops (2 rows × 2).
	if len(created) != 4 {
		t.Fatalf("filled %d plops, want 4 (60×60 bed, radius 15)", len(created))
	}
	for _, p := range created {
		if p.RadiusCM != 15 || p.PlantedAt == nil || p.DerivedCount < 1 {
			t.Errorf("unexpected created plop: %+v", p)
		}
		if p.XCM < -30 || p.XCM > 30 || p.YCM < -30 || p.YCM > 30 {
			t.Errorf("plop center out of bed bounds: %+v", p)
		}
	}

	// Re-filling the same region skips everything (each candidate sits exactly on
	// an existing plop → entirely inside it).
	again, err := s.FillRegion(ctx, owner, bed.ID, region, plant.ID, nil)
	if err != nil {
		t.Fatalf("second FillRegion: %v", err)
	}
	if len(again) != 0 {
		t.Errorf("re-fill created %d plops, want 0 (all covered)", len(again))
	}
}

func TestFillRegionRotatedBedUsesLocalFrame(t *testing.T) {
	ctx := context.Background()
	s := newTestService(t, openConfig())
	owner := seedUser(t, s, "a@example.com")
	g, _ := s.CreateGarden(ctx, owner, GardenInput{Name: "Big", WidthCM: 2000, HeightCM: 2000})
	bed := seedFillBed(t, s, owner, g.ID, 400, 400)
	// Rotate the bed 45°; the fill must still target the LOCAL NE corner.
	rot := 45.0
	bed, _ = s.UpdateObject(ctx, owner, bed.ID, ObjectPatch{RotationDeg: &rot}, bed.Version)
	plant := seedOwnPlant(t, s, owner, 20)

	region, _ := NamedRegion(bed, "ne")
	created, err := s.FillRegion(ctx, owner, bed.ID, region, plant.ID, nil)
	if err != nil {
		t.Fatalf("FillRegion: %v", err)
	}
	if len(created) == 0 {
		t.Fatal("expected some plops in the NE corner")
	}
	for _, p := range created {
		// NE corner in local coords: x ≥ 0 (east), y ≤ 0 (north).
		if p.XCM < 0 || p.YCM > 0 {
			t.Errorf("plop not in local NE corner: %+v", p)
		}
	}
}

func TestClearObject(t *testing.T) {
	ctx := context.Background()
	s := newTestService(t, openConfig())
	owner := seedUser(t, s, "a@example.com")
	g := seedGarden(t, s, owner)
	bed := seedBed(t, s, owner, g.ID)
	plant := seedOwnPlant(t, s, owner, 10)
	region, _ := NamedRegion(bed, "all")
	if _, err := s.FillRegion(ctx, owner, bed.ID, region, plant.ID, nil); err != nil {
		t.Fatalf("fill: %v", err)
	}

	n, err := s.ClearObject(ctx, owner, bed.ID)
	if err != nil {
		t.Fatalf("ClearObject: %v", err)
	}
	if n < 1 {
		t.Fatalf("cleared %d, want ≥ 1", n)
	}
	full, _ := s.GardenFull(ctx, owner, g.ID, nil)
	if len(full.Plantings) != 0 {
		t.Errorf("plantings after clear = %d, want 0", len(full.Plantings))
	}
	// Clearing an already-empty object clears 0.
	if again, _ := s.ClearObject(ctx, owner, bed.ID); again != 0 {
		t.Errorf("second clear = %d, want 0", again)
	}
}

func TestOpsForbiddenForViewer(t *testing.T) {
	ctx := context.Background()
	s := newTestService(t, openConfig())
	owner := seedUser(t, s, "owner@example.com")
	viewer := seedUser(t, s, "viewer@example.com")
	g := seedGarden(t, s, owner)
	bed := seedBed(t, s, owner, g.ID)
	plant := seedOwnPlant(t, s, owner, 10)
	if _, err := s.AddShare(ctx, owner, g.ID, "viewer@example.com", domain.RoleViewer); err != nil {
		t.Fatalf("share: %v", err)
	}
	region, _ := NamedRegion(bed, "all")

	if _, err := s.FillRegion(ctx, viewer, bed.ID, region, plant.ID, nil); !errors.Is(err, domain.ErrForbidden) {
		t.Errorf("viewer fill = %v, want ErrForbidden", err)
	}
	if _, err := s.ClearObject(ctx, viewer, bed.ID); !errors.Is(err, domain.ErrForbidden) {
		t.Errorf("viewer clear = %v, want ErrForbidden", err)
	}
	// But a viewer can DescribeGarden (read).
	if _, err := s.DescribeGarden(ctx, viewer, g.ID); err != nil {
		t.Errorf("viewer describe = %v, want ok", err)
	}
}

// TestFillScenario is the DESIGN scenario: garlic in the NE corner, basil in the
// NW, beans across the south — three distinct groups in the right places.
func TestFillScenario(t *testing.T) {
	ctx := context.Background()
	s := newTestService(t, openConfig())
	owner := seedUser(t, s, "a@example.com")
	g, _ := s.CreateGarden(ctx, owner, GardenInput{Name: "Plot", WidthCM: 2000, HeightCM: 2000})
	bed := seedFillBed(t, s, owner, g.ID, 400, 400)
	garlic := seedNamedPlant(t, s, owner, "Garlic", 15)
	basil := seedNamedPlant(t, s, owner, "Basil", 25)
	beans := seedNamedPlant(t, s, owner, "Beans", 10)

	fill := func(name string, plantID int64) {
		t.Helper()
		region, err := NamedRegion(bed, name)
		if err != nil {
			t.Fatalf("region %q: %v", name, err)
		}
		if _, err := s.FillRegion(ctx, owner, bed.ID, region, plantID, nil); err != nil {
			t.Fatalf("fill %q: %v", name, err)
		}
	}
	fill("ne", garlic.ID)
	fill("nw", basil.ID)
	fill("south", beans.ID)

	desc, err := s.DescribeGarden(ctx, owner, g.ID)
	if err != nil {
		t.Fatalf("DescribeGarden: %v", err)
	}
	if len(desc.Objects) != 1 {
		t.Fatalf("objects = %d, want 1", len(desc.Objects))
	}
	// Tally plant → the set of rough locations it appears in.
	locs := map[string]map[string]bool{}
	for _, p := range desc.Objects[0].Plantings {
		if locs[p.Plant] == nil {
			locs[p.Plant] = map[string]bool{}
		}
		locs[p.Plant][p.Location] = true
	}
	if len(locs["Garlic"]) == 0 || !locs["Garlic"]["NE corner"] {
		t.Errorf("garlic locations = %v, want NE corner", locs["Garlic"])
	}
	if !locs["Basil"]["NW corner"] {
		t.Errorf("basil locations = %v, want NW corner", locs["Basil"])
	}
	// Beans fill the south half → their plops read as "south" (and possibly the
	// SE/SW corners at the edges), never north.
	for loc := range locs["Beans"] {
		if loc == "north" || loc == "NE corner" || loc == "NW corner" || loc == "center" {
			t.Errorf("beans appeared in %q, want only southern locations", loc)
		}
	}
	if len(locs["Beans"]) == 0 {
		t.Error("beans produced no plops")
	}
}

// seedNamedPlant creates a custom plant with a specific name + spacing.
func seedNamedPlant(t *testing.T, s *Service, owner int64, name string, spacingCM float64) *domain.Plant {
	t.Helper()
	p, err := s.CreatePlant(context.Background(), owner, PlantInput{
		Name: name, Category: domain.CategoryVegetable, SpacingCM: spacingCM, Color: "#4a7c3f", Icon: "🌱",
	})
	if err != nil {
		t.Fatalf("seed plant %s: %v", name, err)
	}
	return p
}