1 files changed, 194 insertions, 0 deletions

diff --git a/vrsite/theme.go b/vrsite/theme.go
new file mode 100644
index 0000000..fc63de1
--- /dev/null
+++ b/vrsite/theme.go
@@ -0,0 +1,194 @@
+// theme.go — Zed theme JSON in, CSS custom properties out. Per-agent colors
+// come from the theme's player (collaborator) palette.
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+)
+
+type SyntaxStyle struct {
+	Color      string   `json:"color"`
+	FontStyle  *string  `json:"font_style"`
+	FontWeight *float64 `json:"font_weight"`
+}
+
+type Theme struct {
+	Name, Appearance                             string
+	Bg, Fg, Panel, Border, LineNo, Muted, Accent string
+	Note, Hover                                  string
+	Syntax                                       map[string]SyntaxStyle
+	Players                                      []string
+}
+
+// defaultTheme finds a zed theme file containing a theme of the wanted
+// appearance; "" means fall back to the embedded One family.
+func defaultTheme(appearance string) string {
+	home, _ := os.UserHomeDir()
+	m, _ := filepath.Glob(filepath.Join(home, ".config", "zed", "themes", "*.json"))
+	for _, path := range m {
+		b, err := os.ReadFile(path)
+		if err != nil {
+			continue
+		}
+		var family struct {
+			Themes []struct {
+				Appearance string `json:"appearance"`
+			} `json:"themes"`
+		}
+		if json.Unmarshal(b, &family) != nil {
+			continue
+		}
+		for _, t := range family.Themes {
+			if t.Appearance == appearance {
+				return path
+			}
+		}
+	}
+	return ""
+}
+
+func loadTheme(path, name, appearance string) *Theme {
+	var b []byte
+	var err error
+	if path == "" {
+		b, err = tfs.ReadFile("assets/one.json")
+	} else {
+		b, err = os.ReadFile(path)
+	}
+	if err != nil {
+		fatal("%v", err)
+	}
+	var family struct {
+		Name   string `json:"name"`
+		Themes []struct {
+			Name       string                     `json:"name"`
+			Appearance string                     `json:"appearance"`
+			Style      map[string]json.RawMessage `json:"style"`
+		} `json:"themes"`
+	}
+	if err := json.Unmarshal(b, &family); err != nil || len(family.Themes) == 0 {
+		fatal("bad zed theme %s: %v", path, err)
+	}
+	th := family.Themes[0]
+	if name != "" {
+		for _, t := range family.Themes {
+			if t.Name == name {
+				th = t
+			}
+		}
+	} else {
+		for _, t := range family.Themes {
+			if t.Appearance == appearance {
+				th = t
+				break
+			}
+		}
+	}
+	get := func(keys ...string) string {
+		for _, k := range keys {
+			var s string
+			if raw, ok := th.Style[k]; ok && json.Unmarshal(raw, &s) == nil && s != "" {
+				return s
+			}
+		}
+		return ""
+	}
+	t := &Theme{Name: th.Name, Appearance: th.Appearance,
+		Bg:     get("editor.background", "background"),
+		Fg:     get("editor.foreground", "text"),
+		Panel:  get("panel.background", "surface.background", "background"),
+		Border: get("border", "border.variant"),
+		LineNo: get("editor.line_number"),
+		Muted:  get("text.muted", "text.disabled"),
+		Accent: get("text.accent", "info"),
+		Note:   get("warning", "conflict", "modified"),
+		Hover:  get("element.hover", "ghost_element.hover"),
+	}
+	json.Unmarshal(th.Style["syntax"], &t.Syntax)
+	var players []struct {
+		Cursor string `json:"cursor"`
+	}
+	json.Unmarshal(th.Style["players"], &players)
+	// agent colors: drop player colors that vanish against fg/bg or collide
+	// with the note color, then order greedily for mutual distance so the
+	// first few agents contrast most
+	var usable []string
+	for _, p := range players {
+		c := hex6(p.Cursor)
+		if c != "" && colorDist(c, hex6(t.Fg)) > 60 && colorDist(c, hex6(t.Bg)) > 60 && colorDist(c, hex6(t.Note)) > 60 {
+			usable = append(usable, c)
+		}
+	}
+	for len(usable) > 0 {
+		best, bestScore := 0, -1
+		for i, c := range usable {
+			score := 1 << 24 // first pick: keep theme order
+			for _, p := range t.Players {
+				if d := colorDist(c, p); d < score {
+					score = d
+				}
+			}
+			if score > bestScore {
+				best, bestScore = i, score
+			}
+		}
+		t.Players = append(t.Players, usable[best])
+		usable = append(usable[:best], usable[best+1:]...)
+	}
+	return t
+}
+
+func colorDist(a, b string) int {
+	var ar, ag, ab, br, bg, bb int
+	if len(a) != 7 || len(b) != 7 {
+		return 1 << 24
+	}
+	fmt.Sscanf(a[1:], "%02x%02x%02x", &ar, &ag, &ab)
+	fmt.Sscanf(b[1:], "%02x%02x%02x", &br, &bg, &bb)
+	d := func(x, y int) int { return (x - y) * (x - y) }
+	return int(float64(d(ar, br)+d(ag, bg)+d(ab, bb)) / 3)
+}
+
+var fallbackPalette = []string{"#7aa2f7", "#e0af68", "#9ece6a", "#f7768e", "#bb9af7", "#2ac3de"}
+
+func (t *Theme) Player(i int) string {
+	if i < len(t.Players) {
+		return t.Players[i]
+	}
+	return fallbackPalette[i%len(fallbackPalette)]
+}
+
+// hex6 strips an alpha channel from #rrggbbaa.
+func hex6(c string) string {
+	if len(c) == 9 && c[0] == '#' {
+		return c[:7]
+	}
+	return c
+}
+
+func mixColors(cols []string) string {
+	if len(cols) == 1 {
+		return cols[0]
+	}
+	var r, g, b int
+	n := 0
+	for _, c := range cols {
+		c = hex6(c)
+		if len(c) != 7 {
+			continue
+		}
+		var cr, cg, cb int
+		fmt.Sscanf(c[1:], "%02x%02x%02x", &cr, &cg, &cb)
+		r += cr
+		g += cg
+		b += cb
+		n++
+	}
+	if n == 0 {
+		return "#888888"
+	}
+	return fmt.Sprintf("#%02x%02x%02x", r/n, g/n, b/n)
+}