themes.go

package main

import (
	"encoding/json"
	"os"
	"path/filepath"
	"sort"
)

type Theme struct {
	Name            string `json:"name"`
	Description     string `json:"description"`
	Bg              string `json:"bg"`
	Text            string `json:"text"`
	GradientColor   string `json:"gradient_color"`
	Water           string `json:"water"`
	Parks           string `json:"parks"`
	RoadMotorway    string `json:"road_motorway"`
	RoadPrimary     string `json:"road_primary"`
	RoadSecondary   string `json:"road_secondary"`
	RoadTertiary    string `json:"road_tertiary"`
	RoadResidential string `json:"road_residential"`
	RoadDefault     string `json:"road_default"`
}

const themesDir = "themes"

func getAvailableThemes() ([]string, error) {
	files, err := os.ReadDir(themesDir)
	if err != nil {
		return nil, err
	}

	var themes []string
	for _, file := range files {
		if !file.IsDir() && filepath.Ext(file.Name()) == ".json" {
			themes = append(themes, file.Name()[:len(file.Name())-5])
		}
	}
	sort.Strings(themes)
	return themes, nil
}

func loadTheme(themeName string) (*Theme, error) {
	themeFile := filepath.Join(themesDir, themeName+".json")
	if _, err := os.Stat(themeFile); os.IsNotExist(err) {
		// Fallback to terracotta
		themeFile = filepath.Join(themesDir, "terracotta.json")
	}

	data, err := os.ReadFile(themeFile)
	if err != nil {
		return nil, err
	}

	var theme Theme
	if err := json.Unmarshal(data, &theme); err != nil {
		return nil, err
	}

	return &theme, nil
}