1 files changed, 299 insertions, 0 deletions
diff --git a/packages/tui/internal/theme/system.go b/packages/tui/internal/theme/system.go
new file mode 100644
index 000000000..7524bb3f9
--- /dev/null
+++ b/packages/tui/internal/theme/system.go
@@ -0,0 +1,299 @@
+package theme
+
+import (
+	"fmt"
+	"image/color"
+	"math"
+
+	"github.com/charmbracelet/lipgloss/v2"
+	"github.com/charmbracelet/lipgloss/v2/compat"
+)
+
+// SystemTheme is a dynamic theme that derives its gray scale colors
+// from the terminal's background color at runtime
+type SystemTheme struct {
+	BaseTheme
+	terminalBg       color.Color
+	terminalBgIsDark bool
+}
+
+// NewSystemTheme creates a new instance of the dynamic system theme
+func NewSystemTheme(terminalBg color.Color, isDark bool) *SystemTheme {
+	theme := &SystemTheme{
+		terminalBg:       terminalBg,
+		terminalBgIsDark: isDark,
+	}
+	theme.initializeColors()
+	return theme
+}
+
+// initializeColors sets up all theme colors
+func (t *SystemTheme) initializeColors() {
+	// Generate gray scale based on terminal background
+	grays := t.generateGrayScale()
+
+	// Set ANSI colors for primary colors
+	t.PrimaryColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Cyan,
+		Light: lipgloss.Cyan,
+	}
+	t.SecondaryColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Magenta,
+		Light: lipgloss.Magenta,
+	}
+	t.AccentColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Cyan,
+		Light: lipgloss.Cyan,
+	}
+
+	// Status colors using ANSI
+	t.ErrorColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Red,
+		Light: lipgloss.Red,
+	}
+	t.WarningColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Yellow,
+		Light: lipgloss.Yellow,
+	}
+	t.SuccessColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Green,
+		Light: lipgloss.Green,
+	}
+	t.InfoColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Cyan,
+		Light: lipgloss.Cyan,
+	}
+
+	// Text colors
+	t.TextColor = compat.AdaptiveColor{
+		Dark:  lipgloss.NoColor{},
+		Light: lipgloss.NoColor{},
+	}
+	// Derive muted text color from terminal foreground
+	t.TextMutedColor = t.generateMutedTextColor()
+
+	// Background colors
+	t.BackgroundColor = compat.AdaptiveColor{
+		Dark:  lipgloss.NoColor{},
+		Light: lipgloss.NoColor{},
+	}
+	t.BackgroundPanelColor = grays[2]
+	t.BackgroundElementColor = grays[3]
+
+	// Border colors
+	t.BorderSubtleColor = grays[6]
+	t.BorderColor = grays[7]
+	t.BorderActiveColor = grays[8]
+
+	// Diff colors using ANSI colors
+	t.DiffAddedColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("2"), // green
+		Light: lipgloss.Color("2"),
+	}
+	t.DiffRemovedColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("1"), // red
+		Light: lipgloss.Color("1"),
+	}
+	t.DiffContextColor = grays[7] // Use gray for context
+	t.DiffHunkHeaderColor = grays[7]
+	t.DiffHighlightAddedColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("2"), // green
+		Light: lipgloss.Color("2"),
+	}
+	t.DiffHighlightRemovedColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("1"), // red
+		Light: lipgloss.Color("1"),
+	}
+	// Use subtle gray backgrounds for diff
+	t.DiffAddedBgColor = grays[2]
+	t.DiffRemovedBgColor = grays[2]
+	t.DiffContextBgColor = grays[1]
+	t.DiffLineNumberColor = grays[6]
+	t.DiffAddedLineNumberBgColor = grays[3]
+	t.DiffRemovedLineNumberBgColor = grays[3]
+
+	// Markdown colors using ANSI
+	t.MarkdownTextColor = compat.AdaptiveColor{
+		Dark:  lipgloss.NoColor{},
+		Light: lipgloss.NoColor{},
+	}
+	t.MarkdownHeadingColor = compat.AdaptiveColor{
+		Dark:  lipgloss.NoColor{},
+		Light: lipgloss.NoColor{},
+	}
+	t.MarkdownLinkColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("4"), // blue
+		Light: lipgloss.Color("4"),
+	}
+	t.MarkdownLinkTextColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("6"), // cyan
+		Light: lipgloss.Color("6"),
+	}
+	t.MarkdownCodeColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("2"), // green
+		Light: lipgloss.Color("2"),
+	}
+	t.MarkdownBlockQuoteColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("3"), // yellow
+		Light: lipgloss.Color("3"),
+	}
+	t.MarkdownEmphColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("3"), // yellow
+		Light: lipgloss.Color("3"),
+	}
+	t.MarkdownStrongColor = compat.AdaptiveColor{
+		Dark:  lipgloss.NoColor{},
+		Light: lipgloss.NoColor{},
+	}
+	t.MarkdownHorizontalRuleColor = t.BorderColor
+	t.MarkdownListItemColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("4"), // blue
+		Light: lipgloss.Color("4"),
+	}
+	t.MarkdownListEnumerationColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("6"), // cyan
+		Light: lipgloss.Color("6"),
+	}
+	t.MarkdownImageColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("4"), // blue
+		Light: lipgloss.Color("4"),
+	}
+	t.MarkdownImageTextColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("6"), // cyan
+		Light: lipgloss.Color("6"),
+	}
+	t.MarkdownCodeBlockColor = compat.AdaptiveColor{
+		Dark:  lipgloss.NoColor{},
+		Light: lipgloss.NoColor{},
+	}
+
+	// Syntax colors
+	t.SyntaxCommentColor = t.TextMutedColor // Use same as muted text
+	t.SyntaxKeywordColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("5"), // magenta
+		Light: lipgloss.Color("5"),
+	}
+	t.SyntaxFunctionColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("4"), // blue
+		Light: lipgloss.Color("4"),
+	}
+	t.SyntaxVariableColor = compat.AdaptiveColor{
+		Dark:  lipgloss.NoColor{},
+		Light: lipgloss.NoColor{},
+	}
+	t.SyntaxStringColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("2"), // green
+		Light: lipgloss.Color("2"),
+	}
+	t.SyntaxNumberColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("3"), // yellow
+		Light: lipgloss.Color("3"),
+	}
+	t.SyntaxTypeColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("6"), // cyan
+		Light: lipgloss.Color("6"),
+	}
+	t.SyntaxOperatorColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("6"), // cyan
+		Light: lipgloss.Color("6"),
+	}
+	t.SyntaxPunctuationColor = compat.AdaptiveColor{
+		Dark:  lipgloss.NoColor{},
+		Light: lipgloss.NoColor{},
+	}
+}
+
+// generateGrayScale creates a gray scale based on the terminal background
+func (t *SystemTheme) generateGrayScale() map[int]compat.AdaptiveColor {
+	grays := make(map[int]compat.AdaptiveColor)
+
+	r, g, b, _ := t.terminalBg.RGBA()
+	bgR := float64(r >> 8)
+	bgG := float64(g >> 8)
+	bgB := float64(b >> 8)
+
+	luminance := 0.299*bgR + 0.587*bgG + 0.114*bgB
+
+	for i := 1; i <= 12; i++ {
+		var stepColor string
+		factor := float64(i) / 12.0
+
+		if t.terminalBgIsDark {
+			if luminance < 10 {
+				grayValue := int(factor * 0.4 * 255)
+				stepColor = fmt.Sprintf("#%02x%02x%02x", grayValue, grayValue, grayValue)
+			} else {
+				newLum := luminance + (255-luminance)*factor*0.4
+
+				ratio := newLum / luminance
+				newR := math.Min(bgR*ratio, 255)
+				newG := math.Min(bgG*ratio, 255)
+				newB := math.Min(bgB*ratio, 255)
+
+				stepColor = fmt.Sprintf("#%02x%02x%02x", int(newR), int(newG), int(newB))
+			}
+		} else {
+			if luminance > 245 {
+				grayValue := int(255 - factor*0.4*255)
+				stepColor = fmt.Sprintf("#%02x%02x%02x", grayValue, grayValue, grayValue)
+			} else {
+				newLum := luminance * (1 - factor*0.4)
+
+				ratio := newLum / luminance
+				newR := math.Max(bgR*ratio, 0)
+				newG := math.Max(bgG*ratio, 0)
+				newB := math.Max(bgB*ratio, 0)
+
+				stepColor = fmt.Sprintf("#%02x%02x%02x", int(newR), int(newG), int(newB))
+			}
+		}
+
+		grays[i] = compat.AdaptiveColor{
+			Dark:  lipgloss.Color(stepColor),
+			Light: lipgloss.Color(stepColor),
+		}
+	}
+
+	return grays
+}
+
+// generateMutedTextColor creates a muted gray color based on the terminal background
+func (t *SystemTheme) generateMutedTextColor() compat.AdaptiveColor {
+	bgR, bgG, bgB, _ := t.terminalBg.RGBA()
+
+	bgRf := float64(bgR >> 8)
+	bgGf := float64(bgG >> 8)
+	bgBf := float64(bgB >> 8)
+
+	bgLum := 0.299*bgRf + 0.587*bgGf + 0.114*bgBf
+
+	var grayValue int
+	if t.terminalBgIsDark {
+		if bgLum < 10 {
+			// Very dark/black background
+			// grays[3] would be around #2e (46), so we need much lighter
+			grayValue = 180 // #b4b4b4
+		} else {
+			// Scale up for lighter dark backgrounds
+			// Ensure we're always significantly brighter than BackgroundElement
+			grayValue = min(int(160+(bgLum*0.3)), 200)
+		}
+	} else {
+		if bgLum > 245 {
+			// Very light/white background
+			// grays[3] would be around #f5 (245), so we need much darker
+			grayValue = 75 // #4b4b4b
+		} else {
+			// Scale down for darker light backgrounds
+			// Ensure we're always significantly darker than BackgroundElement
+			grayValue = max(int(100-((255-bgLum)*0.2)), 60)
+		}
+	}
+
+	mutedColor := fmt.Sprintf("#%02x%02x%02x", grayValue, grayValue, grayValue)
+
+	return compat.AdaptiveColor{
+		Dark:  lipgloss.Color(mutedColor),
+		Light: lipgloss.Color(mutedColor),
+	}
+}