From 4b7fe0d58402c7ad112f3c4fc5983d81cb037b5f Mon Sep 17 00:00:00 2001
From: Snider <snider@host.uk.com>
Date: Thu, 23 Jul 2026 17:07:19 +0100
Subject: [PATCH] =?UTF-8?q?feat(display/tui/style):=20AdaptiveColor=20?=
 =?UTF-8?q?=E2=80=94=20the=20light/dark=20pair=20lipgloss=20v2=20dropped?=
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lipgloss v2 removed the v1 AdaptiveColor type (implicit light/dark adaptation)
in favour of an explicit isDark resolve. This restores the paired shape as
data — AdaptiveColor{Light, Dark string} + Resolve(isDark) delegating to
NewLightDark — so a consumer's theme keeps its v1 shape and adds one resolve
step per frame. Unblocks go-inference cli/tui's charm-free migration
(10-field theme, 22 paint sites). One test per variant + an Example.

Co-Authored-By: Virgil <virgil@lethean.io>
---
 go/display/tui/style/color.go        | 18 +++++++++++++++
 go/display/tui/style/color_test.go   | 33 ++++++++++++++++++++++++++++
 go/display/tui/style/example_test.go | 12 ++++++++++
 3 files changed, 63 insertions(+)
 create mode 100644 go/display/tui/style/color_test.go

diff --git a/go/display/tui/style/color.go b/go/display/tui/style/color.go
index d075f17..a3951bb 100644
--- a/go/display/tui/style/color.go
+++ b/go/display/tui/style/color.go
@@ -21,3 +21,21 @@ type LightDark = lipgloss.LightDarkFunc
 
 // NewLightDark builds a LightDark chooser for the given background.
 func NewLightDark(isDark bool) LightDark { return lipgloss.LightDark(isDark) }
+
+// AdaptiveColor pairs a light-background and a dark-background colour for one
+// role, resolved once the terminal background is known — the render-time
+// replacement for lipgloss v1's implicit adaptation, which v2 removed. A theme
+// keeps the pair as data and resolves it per frame, e.g.
+//
+//	accent := style.AdaptiveColor{Light: "#2e5cc5", Dark: "#7aa2f7"}
+//	st := style.New().Foreground(accent.Resolve(isDark))
+type AdaptiveColor struct {
+	Light, Dark string
+}
+
+// Resolve returns the Light Paint on a light terminal and the Dark Paint on a
+// dark one, delegating to NewLightDark so it matches every other light/dark
+// choice in the package.
+func (a AdaptiveColor) Resolve(isDark bool) Paint {
+	return NewLightDark(isDark)(Color(a.Light), Color(a.Dark))
+}
diff --git a/go/display/tui/style/color_test.go b/go/display/tui/style/color_test.go
new file mode 100644
index 0000000..9d2acb2
--- /dev/null
+++ b/go/display/tui/style/color_test.go
@@ -0,0 +1,33 @@
+package style_test
+
+import (
+	"testing"
+
+	"dappco.re/go/html/display/tui/style"
+)
+
+func TestAdaptiveColor_Resolve_PicksDarkOnADarkTerminal(t *testing.T) {
+	c := style.AdaptiveColor{Light: "#000000", Dark: "#ffffff"}
+
+	r, g, b, _ := c.Resolve(true).RGBA()
+	if r != 0xffff || g != 0xffff || b != 0xffff {
+		t.Fatalf("Resolve(isDark=true) = %d,%d,%d, want the Dark colour white (65535,65535,65535)", r, g, b)
+	}
+}
+
+func TestAdaptiveColor_Resolve_PicksLightOnALightTerminal(t *testing.T) {
+	c := style.AdaptiveColor{Light: "#000000", Dark: "#ffffff"}
+
+	r, g, b, _ := c.Resolve(false).RGBA()
+	if r != 0 || g != 0 || b != 0 {
+		t.Fatalf("Resolve(isDark=false) = %d,%d,%d, want the Light colour black (0,0,0)", r, g, b)
+	}
+}
+
+func TestAdaptiveColor_Resolve_ZeroValueResolvesWithoutPanicking(t *testing.T) {
+	var c style.AdaptiveColor // both fields empty — an unset theme role
+
+	if got := c.Resolve(true); got == nil {
+		t.Fatal("Resolve on a zero AdaptiveColor returned a nil Paint, want a non-nil no-colour")
+	}
+}
diff --git a/go/display/tui/style/example_test.go b/go/display/tui/style/example_test.go
index cd03791..9849e4c 100644
--- a/go/display/tui/style/example_test.go
+++ b/go/display/tui/style/example_test.go
@@ -32,3 +32,15 @@ func ExampleBlend1D() {
 	// Output:
 	// true
 }
+
+// ExampleAdaptiveColor_Resolve keeps one light/dark colour pair and resolves it
+// for a dark terminal — the per-frame replacement for lipgloss v1's implicit
+// AdaptiveColor, which v2 removed.
+func ExampleAdaptiveColor_Resolve() {
+	accent := style.AdaptiveColor{Light: "#000000", Dark: "#ffffff"}
+
+	r, g, b, _ := accent.Resolve(true).RGBA()
+	fmt.Printf("%d %d %d\n", r, g, b)
+	// Output:
+	// 65535 65535 65535
+}