Colour themes, defaulting to gruvbox dark

Every colour was a 256-colour ANSI index hardcoded in styles.go, so changing
the palette meant editing the styles themselves. This puts a semantic token set
between the two: styles name roles, a theme supplies the colours.

internal/theme holds the twelve tokens, the two built-ins (gruvbox-dark, the
new default, and gruvbox-light) and the loader for user themes in
~/.config/terdut-tui/themes/. A user file may 'extends:' a built-in and
override only what it cares about, and may shadow a built-in name to tweak it
in place. Unknown keys, malformed colours and incomplete themes are refused
with a message naming what went wrong.

Colours are truecolor hex now: lipgloss downsamples for 256- and 16-colour
terminals and honours NO_COLOR, so themes carry no fallbacks of their own.
An ANSI index is still accepted for anyone who would rather follow their
terminal's own palette.

The 21 package-level style vars become a Styles struct on the Model, which is
what rule 3 asked for all along; the four free functions in view.go take one as
their first argument. The embedded bubbles components are restyled from the
same tokens — otherwise a theme would leave a pink selected row and grey help
text behind. Note that the table's Cell style deliberately keeps no foreground:
bubbles renders cells before wrapping the row in Selected, so a colour there
cuts the selection highlight short.

internal/tui/styles.go

@@ -4,96 +4,172 @@ import (
 	"strings"
 
 	"git.ryuvia.com/niklas/terdut-tui/internal/api"
+	"git.ryuvia.com/niklas/terdut-tui/internal/theme"
+	"github.com/charmbracelet/bubbles/help"
+	"github.com/charmbracelet/bubbles/table"
+	"github.com/charmbracelet/bubbles/textinput"
 	"github.com/charmbracelet/lipgloss"
 )
 
-var (
-	colorPrimary  = lipgloss.Color("69")  // blue
-	colorMuted    = lipgloss.Color("240") // gray
-	colorFiring   = lipgloss.Color("196") // red
-	colorResolved = lipgloss.Color("70")  // green
-	colorAccent   = lipgloss.Color("214") // orange
+// Styles is every style the views draw with, built once from a theme and held
+// on the Model. Nothing here reads a colour literal: the theme is the only
+// place a colour is named.
+type Styles struct {
+	Header      lipgloss.Style
+	TabActive   lipgloss.Style
+	TabInactive lipgloss.Style
+	Footer      lipgloss.Style
+	Status      lipgloss.Style
 
-	colorSevCritical = lipgloss.Color("196") // red
-	colorSevError    = lipgloss.Color("202") // dark orange
-	colorSevWarning  = lipgloss.Color("214") // orange
-	colorSevInfo     = lipgloss.Color("39")  // cyan
-
-	styleHeader = lipgloss.NewStyle().
-			Bold(true).
-			Foreground(colorPrimary).
-			Padding(0, 1)
-
-	styleTabActive = lipgloss.NewStyle().
-			Bold(true).
-			Foreground(lipgloss.Color("0")).
-			Background(colorPrimary).
-			Padding(0, 2)
-
-	styleTabInactive = lipgloss.NewStyle().
-				Foreground(colorMuted).
-				Padding(0, 2)
-
-	styleFooter = lipgloss.NewStyle().
-			Foreground(colorMuted)
-
-	styleStatus = lipgloss.NewStyle().
-			Foreground(colorAccent).
-			Bold(true)
-
-	styleError = lipgloss.NewStyle().
-			Foreground(colorFiring).
-			Bold(true)
-
-	styleFiring    = lipgloss.NewStyle().Foreground(colorFiring).Bold(true)
-	styleResolved  = lipgloss.NewStyle().Foreground(colorResolved)
-	styleMuted     = lipgloss.NewStyle().Foreground(colorMuted)
-	styleAlertName = lipgloss.NewStyle().Bold(true)
-	styleBold      = lipgloss.NewStyle().Bold(true)
-	styleSelected  = lipgloss.NewStyle().Foreground(colorPrimary).Bold(true)
-	styleAccent    = lipgloss.NewStyle().Foreground(colorAccent)
+	Error     lipgloss.Style
+	Firing    lipgloss.Style
+	Resolved  lipgloss.Style
+	Muted     lipgloss.Style
+	Accent    lipgloss.Style
+	AlertName lipgloss.Style
+	Bold      lipgloss.Style
+	Selected  lipgloss.Style
 
 	// Incident status. Triggered is unclaimed work and reads as loudly as a
 	// firing alert; acknowledged means somebody has it.
-	styleTriggered    = lipgloss.NewStyle().Foreground(colorFiring).Bold(true)
-	styleAcknowledged = lipgloss.NewStyle().Foreground(colorAccent).Bold(true)
-	styleSnoozed      = lipgloss.NewStyle().Foreground(colorMuted).Italic(true)
+	Triggered    lipgloss.Style
+	Acknowledged lipgloss.Style
+	Snoozed      lipgloss.Style
 
 	// Severity, over the conventional Alertmanager label values.
-	styleSevCritical = lipgloss.NewStyle().Foreground(colorSevCritical).Bold(true)
-	styleSevError    = lipgloss.NewStyle().Foreground(colorSevError).Bold(true)
-	styleSevWarning  = lipgloss.NewStyle().Foreground(colorSevWarning)
-	styleSevInfo     = lipgloss.NewStyle().Foreground(colorSevInfo)
-)
+	SevCritical lipgloss.Style
+	SevError    lipgloss.Style
+	SevWarning  lipgloss.Style
+	SevInfo     lipgloss.Style
 
-// severityStyle picks the style for a severity label, falling back to muted for
+	theme theme.Theme
+}
+
+func newStyles(t theme.Theme) Styles {
+	return Styles{
+		Header: lipgloss.NewStyle().
+			Bold(true).
+			Foreground(t.Primary).
+			Padding(0, 1),
+
+		TabActive: lipgloss.NewStyle().
+			Bold(true).
+			Foreground(t.OnPrimary).
+			Background(t.Primary).
+			Padding(0, 2),
+
+		TabInactive: lipgloss.NewStyle().
+			Foreground(t.Muted).
+			Padding(0, 2),
+
+		Footer: lipgloss.NewStyle().Foreground(t.Muted),
+
+		Status: lipgloss.NewStyle().
+			Foreground(t.Accent).
+			Bold(true),
+
+		Error: lipgloss.NewStyle().
+			Foreground(t.Error).
+			Bold(true),
+
+		Firing:    lipgloss.NewStyle().Foreground(t.Firing).Bold(true),
+		Resolved:  lipgloss.NewStyle().Foreground(t.Resolved),
+		Muted:     lipgloss.NewStyle().Foreground(t.Muted),
+		Accent:    lipgloss.NewStyle().Foreground(t.Accent),
+		AlertName: lipgloss.NewStyle().Foreground(t.Text).Bold(true),
+		Bold:      lipgloss.NewStyle().Foreground(t.Text).Bold(true),
+		Selected:  lipgloss.NewStyle().Foreground(t.Primary).Bold(true),
+
+		Triggered:    lipgloss.NewStyle().Foreground(t.Firing).Bold(true),
+		Acknowledged: lipgloss.NewStyle().Foreground(t.Accent).Bold(true),
+		Snoozed:      lipgloss.NewStyle().Foreground(t.Muted).Italic(true),
+
+		SevCritical: lipgloss.NewStyle().Foreground(t.SevCritical).Bold(true),
+		SevError:    lipgloss.NewStyle().Foreground(t.SevError).Bold(true),
+		SevWarning:  lipgloss.NewStyle().Foreground(t.SevWarning),
+		SevInfo:     lipgloss.NewStyle().Foreground(t.SevInfo),
+
+		theme: t,
+	}
+}
+
+// Severity picks the style for a severity label, falling back to muted for
 // values this client does not recognise rather than dropping them.
-func severityStyle(severity string) lipgloss.Style {
+func (s Styles) Severity(severity string) lipgloss.Style {
 	switch strings.ToLower(severity) {
 	case "critical":
-		return styleSevCritical
+		return s.SevCritical
 	case "error":
-		return styleSevError
+		return s.SevError
 	case "warning":
-		return styleSevWarning
+		return s.SevWarning
 	case "info":
-		return styleSevInfo
+		return s.SevInfo
 	default:
-		return styleMuted
+		return s.Muted
 	}
 }
 
-// incidentStatusStyle picks the style for an incident status, falling back to
-// muted for statuses added after this client was built.
-func incidentStatusStyle(status string) lipgloss.Style {
+// IncidentStatus picks the style for an incident status, falling back to muted
+// for statuses added after this client was built.
+func (s Styles) IncidentStatus(status string) lipgloss.Style {
 	switch status {
 	case api.StatusTriggered:
-		return styleTriggered
+		return s.Triggered
 	case api.StatusAcknowledged:
-		return styleAcknowledged
+		return s.Acknowledged
 	case api.StatusResolved:
-		return styleResolved
+		return s.Resolved
 	default:
-		return styleMuted
+		return s.Muted
 	}
 }
+
+// ── Embedded bubbles components ────────────────────────────────────────────
+//
+// Each ships its own hardcoded palette, so a theme that stopped at this
+// package's own styles would leave a pink selected row and grey help text
+// behind. These three restyle them from the same tokens.
+
+// Table styles the six tables. Padding comes from the bubbles defaults; only
+// the colours are ours.
+func (s Styles) Table() table.Styles {
+	ts := table.DefaultStyles()
+	ts.Header = ts.Header.Foreground(s.theme.Muted).Bold(true)
+	// Cell deliberately keeps no foreground: bubbles renders each cell before
+	// wrapping the whole row in Selected, so a colour here would emit a reset
+	// mid-row and cut the selection highlight short.
+	ts.Selected = ts.Selected.
+		Foreground(s.theme.OnPrimary).
+		Background(s.theme.Primary).
+		Bold(true)
+	return ts
+}
+
+// Help styles the key hints in the footer.
+func (s Styles) Help() help.Styles {
+	key := lipgloss.NewStyle().Foreground(s.theme.Text)
+	desc := lipgloss.NewStyle().Foreground(s.theme.Muted)
+	sep := lipgloss.NewStyle().Foreground(s.theme.Muted)
+
+	return help.Styles{
+		Ellipsis:       sep,
+		ShortKey:       key,
+		ShortDesc:      desc,
+		ShortSeparator: sep,
+		FullKey:        key,
+		FullDesc:       desc,
+		FullSeparator:  sep,
+	}
+}
+
+// Input styles a text input and returns it, so NewModel can wrap each one as
+// it is built.
+func (s Styles) Input(ti textinput.Model) textinput.Model {
+	ti.PromptStyle = lipgloss.NewStyle().Foreground(s.theme.Primary)
+	ti.TextStyle = lipgloss.NewStyle().Foreground(s.theme.Text)
+	ti.PlaceholderStyle = lipgloss.NewStyle().Foreground(s.theme.Muted)
+	ti.CompletionStyle = lipgloss.NewStyle().Foreground(s.theme.Muted)
+	ti.Cursor.Style = lipgloss.NewStyle().Foreground(s.theme.Primary)
+	return ti
+}