// Package tmux provides theme support for Gas Town tmux sessions.
package tmux

import (
	"fmt"
	"hash/fnv"
)

// Theme represents a tmux status bar color scheme.
type Theme struct {
	Name string // Human-readable name
	BG   string // Background color (hex or tmux color name)
	FG   string // Foreground color (hex or tmux color name)
}

// DefaultPalette is the curated set of distinct, professional color themes.
// Each theme has good contrast and is visually distinct from others.
var DefaultPalette = []Theme{
	{Name: "ocean", BG: "#1e3a5f", FG: "#e0e0e0"},    // Deep blue
	{Name: "forest", BG: "#2d5a3d", FG: "#e0e0e0"},   // Forest green
	{Name: "rust", BG: "#8b4513", FG: "#f5f5dc"},     // Rust/brown
	{Name: "plum", BG: "#4a3050", FG: "#e0e0e0"},     // Purple
	{Name: "slate", BG: "#4a5568", FG: "#e0e0e0"},    // Slate gray
	{Name: "ember", BG: "#b33a00", FG: "#f5f5dc"},    // Burnt orange
	{Name: "midnight", BG: "#1a1a2e", FG: "#c0c0c0"}, // Dark blue-black
	{Name: "wine", BG: "#722f37", FG: "#f5f5dc"},     // Burgundy
	{Name: "teal", BG: "#0d5c63", FG: "#e0e0e0"},     // Teal
	{Name: "copper", BG: "#6d4c41", FG: "#f5f5dc"},   // Warm brown
}

// MayorTheme returns the special theme for the Mayor session.
// Gold/dark to distinguish it from rig themes.
func MayorTheme() Theme {
	return Theme{Name: "mayor", BG: "#3d3200", FG: "#ffd700"}
}

// DeaconTheme returns the special theme for the Deacon session.
// Purple/silver - ecclesiastical, distinct from Mayor's gold.
func DeaconTheme() Theme {
	return Theme{Name: "deacon", BG: "#2d1f3d", FG: "#c0b0d0"}
}

// GetThemeByName finds a theme by name from the default palette.
// Returns nil if not found.
func GetThemeByName(name string) *Theme {
	for _, t := range DefaultPalette {
		if t.Name == name {
			return &t
		}
	}
	return nil
}

// AssignTheme picks a theme for a rig based on its name.
// Uses consistent hashing so the same rig always gets the same color.
func AssignTheme(rigName string) Theme {
	return AssignThemeFromPalette(rigName, DefaultPalette)
}

// AssignThemeFromPalette picks a theme using a custom palette.
func AssignThemeFromPalette(rigName string, palette []Theme) Theme {
	if len(palette) == 0 {
		return DefaultPalette[0]
	}
	h := fnv.New32a()
	_, _ = h.Write([]byte(rigName))
	idx := int(h.Sum32()) % len(palette)
	return palette[idx]
}

// Style returns the tmux status-style string for this theme.
func (t Theme) Style() string {
	return fmt.Sprintf("bg=%s,fg=%s", t.BG, t.FG)
}

// ListThemeNames returns the names of all themes in the default palette.
func ListThemeNames() []string {
	names := make([]string, len(DefaultPalette))
	for i, t := range DefaultPalette {
		names[i] = t.Name
	}
	return names
}