package viewmap

import (
	"strings"
	"testing"

	"github.com/lwoodard/rtsp-streamer/internal/protect"
)

// view builds a live view whose slots each hold one camera id.
func view(name string, ids ...string) protect.LiveView {
	v := protect.LiveView{Name: name}
	for _, id := range ids {
		v.Slots = append(v.Slots, protect.LiveViewSlot{Cameras: []string{id}})
	}
	return v
}

// namesFor maps ids "c0".."cN-1" to themselves so tiles are easy to assert on.
func namesFor(n int) map[string]string {
	m := map[string]string{}
	for i := 0; i < n; i++ {
		m[id(i)] = id(i)
	}
	return m
}

func id(i int) string { return string(rune('a' + i)) }

func ids(n int) []string {
	out := make([]string, n)
	for i := range out {
		out[i] = id(i)
	}
	return out
}

// The 8-camera Protect preset is asymmetric: four 2x2 tiles plus a right-hand
// column of four 1x1 tiles, tiling a 5x4 grid exactly.
func TestLayoutFromView_EightSlotPreset(t *testing.T) {
	got, warns := LayoutFromView(view("Office View", ids(8)...), namesFor(8))

	if got.Grid != "5x4" {
		t.Fatalf("grid = %q, want 5x4", got.Grid)
	}
	if len(warns) != 0 {
		t.Errorf("unexpected warnings: %v", warns)
	}
	if got.ProtectView != "Office View" || got.Name != "office-view" {
		t.Errorf("name/link = %q/%q", got.Name, got.ProtectView)
	}

	want := []struct{ col, row, cs, rs int }{
		{0, 0, 2, 2}, {2, 0, 2, 2}, {4, 0, 1, 1}, {4, 1, 1, 1},
		{0, 2, 2, 2}, {2, 2, 2, 2}, {4, 2, 1, 1}, {4, 3, 1, 1},
	}
	if len(got.Tiles) != len(want) {
		t.Fatalf("got %d tiles, want %d", len(got.Tiles), len(want))
	}
	for i, w := range want {
		tile := got.Tiles[i]
		cs, rs := tile.Span()
		if tile.Col != w.col || tile.Row != w.row || cs != w.cs || rs != w.rs {
			t.Errorf("tile %d = (%d,%d)+%dx%d, want (%d,%d)+%dx%d",
				i, tile.Col, tile.Row, cs, rs, w.col, w.row, w.cs, w.rs)
		}
		if tile.Camera != id(i) {
			t.Errorf("tile %d camera = %q, want %q", i, tile.Camera, id(i))
		}
	}
}

// The 8-slot preset must leave no holes; that was the original bug (8 tiles
// dropped into a 3x3 grid left the bottom-right cell blank).
func TestLayoutFromView_EightSlotsTileGridExactly(t *testing.T) {
	got, _ := LayoutFromView(view("Office View", ids(8)...), namesFor(8))
	if n := unfilled(presetForSlots(8), got.Tiles); n != 0 {
		t.Errorf("%d cells left empty, want 0", n)
	}
}

// Counts without a preset keep the uniform row-major grid.
func TestLayoutFromView_UniformFallback(t *testing.T) {
	got, warns := LayoutFromView(view("Default", ids(9)...), namesFor(9))
	if got.Grid != "3x3" {
		t.Fatalf("grid = %q, want 3x3", got.Grid)
	}
	if len(warns) != 0 {
		t.Errorf("unexpected warnings: %v", warns)
	}
	for i, tile := range got.Tiles {
		if tile.Col != i%3 || tile.Row != i/3 {
			t.Errorf("tile %d at (%d,%d), want (%d,%d)", i, tile.Col, tile.Row, i%3, i/3)
		}
	}
}

// A count whose uniform grid is larger than the slot count leaves holes, and
// the caller must be told rather than silently shipping a wall with blanks.
func TestLayoutFromView_WarnsOnHoles(t *testing.T) {
	got, warns := LayoutFromView(view("Seven", ids(7)...), namesFor(7))
	if got.Grid != "3x3" {
		t.Fatalf("grid = %q, want 3x3", got.Grid)
	}
	if !hasWarn(warns, "empty") {
		t.Errorf("expected an empty-cell warning, got %v", warns)
	}
}

// An unknown camera id is reported and its cell left out.
func TestLayoutFromView_WarnsOnUnknownCamera(t *testing.T) {
	got, warns := LayoutFromView(view("Office View", ids(8)...), namesFor(7))
	if len(got.Tiles) != 7 {
		t.Errorf("got %d tiles, want 7", len(got.Tiles))
	}
	if !hasWarn(warns, "not in config") {
		t.Errorf("expected an unknown-camera warning, got %v", warns)
	}
}

func TestUnfilledCountsUncoveredCells(t *testing.T) {
	p := uniformPreset(3, 3)
	if n := unfilled(p, nil); n != 9 {
		t.Errorf("empty layout: got %d uncovered, want 9", n)
	}
	full, _ := LayoutFromView(view("Default", ids(9)...), namesFor(9))
	if n := unfilled(p, full.Tiles); n != 0 {
		t.Errorf("full 3x3: got %d uncovered, want 0", n)
	}
}

func hasWarn(warns []string, substr string) bool {
	for _, w := range warns {
		if strings.Contains(w, substr) {
			return true
		}
	}
	return false
}