package config

import (
	"regexp"
	"strings"
)

// templateName matches a route template: a valid route name ending in "-*".
var templateName = regexp.MustCompile(`^[a-z0-9][a-z0-9-]*-\*$`)

// Route resolves a request route name: an exact entry wins; else the longest template
// "<prefix>-*" whose prefix (including the dash) starts name with a non-empty remainder;
// else ok is false. key is the config key that matched (the template's name for a template).
// A name that is not a valid route name (the pattern below) or contains '*' never matches.
func (c *Config) Route(name string) (r Route, key string, ok bool) {
	if !routeName.MatchString(name) {
		return Route{}, "", false
	}
	if rt, found := c.Routes[name]; found {
		return rt, name, true
	}
	var (
		best    Route
		bestKey string
		bestLen int
	)
	for tmpl, rt := range c.Routes {
		if !templateName.MatchString(tmpl) {
			continue
		}
		prefix := tmpl[:len(tmpl)-1] // drop the trailing '*', keeping the dash
		if len(prefix) > bestLen && strings.HasPrefix(name, prefix) && len(name) > len(prefix) {
			best, bestKey, bestLen = rt, tmpl, len(prefix)
		}
	}
	if bestKey == "" {
		return Route{}, "", false
	}
	return best, bestKey, true
}