package panel

import (
	"embed"
	"fmt"
	"html/template"
	"io/fs"
	"net/http"
	"os"
)

//go:embed templates static
var embeddedFS embed.FS

var templateFuncs = template.FuncMap{
	"percent": func(count, max int) int {
		if max <= 0 {
			return 0
		}
		v := count * 100 / max
		if v > 100 {
			return 100
		}
		return v
	},
	"fmtMin": func(m int) string {
		if m <= 0 {
			return "—"
		}
		if m < 60 {
			return fmt.Sprintf("%dm", m)
		}
		return fmt.Sprintf("%dh%dm", m/60, m%60)
	},
	"add": func(a, b int) int { return a + b },
	// dict builds a map[string]any for passing multiple values to a sub-template.
	"dict": func(pairs ...any) map[string]any {
		m := make(map[string]any, len(pairs)/2)
		for i := 0; i+1 < len(pairs); i += 2 {
			k, _ := pairs[i].(string)
			m[k] = pairs[i+1]
		}
		return m
	},
	"buttonClass": func(color string) string {
		switch color {
		case "secondary":
			return "bg-gray-600"
		case "success":
			return "bg-green-600"
		case "danger":
			return "bg-red-600"
		default:
			return "bg-indigo-600"
		}
	},
	"not": func(v bool) bool { return !v },
}

// StaticFS returns the file system to use for /static/* routes.
// In dev mode (PANEL_DEV=true), serves from disk for hot reload.
func StaticFS() http.FileSystem {
	if os.Getenv("PANEL_DEV") == "true" {
		return http.Dir("internal/panel/static")
	}
	sub, _ := fs.Sub(embeddedFS, "static")
	return http.FS(sub)
}

// ParseTemplates parses a set of template files by name with global template functions.
// In dev mode templates are loaded from disk on every call (hot reload).
func ParseTemplates(names ...string) (*template.Template, error) {
	var paths []string
	for _, n := range names {
		paths = append(paths, "templates/"+n)
	}
	base := template.New("").Funcs(templateFuncs)
	if os.Getenv("PANEL_DEV") == "true" {
		return base.ParseFiles(prependDir("internal/panel/", paths)...)
	}
	return base.ParseFS(embeddedFS, paths...)
}

func prependDir(dir string, paths []string) []string {
	out := make([]string, len(paths))
	for i, p := range paths {
		out[i] = dir + p
	}
	return out
}