package yu_url

import "strings"

// Values maps a string key to a list of values.
// It is typically used for query parameters and form values.
// Unlike in the http.Header map, the keys in a Values map
// are case-sensitive.
type Values map[string][]string

// Get gets the first value associated with the given key.
// If there are no values associated with the key, Get returns
// the empty string. To access multiple values, use the map
// directly.
func (v Values) Get(key string) string {
	vs := v[key]
	if len(vs) == 0 {
		return ""
	}
	return vs[0]
}

// Gets gets the first value associated with the given key.
// If there are no values associated with the key, Get returns
// the empty string. To access multiple values, use the map
// directly.
func (v Values) Gets(key string) []string {
	return v[key]
}

// Set sets the key to value. It replaces any existing
// values.
func (v Values) Set(key, value string) {
	v[key] = []string{value}
}

// Add adds the value to key. It appends to any existing
// values associated with key.
func (v Values) Add(key, value string) {
	v[key] = append(v[key], value)
}

// Del deletes the values associated with key.
func (v Values) Del(key string) {
	delete(v, key)
}

// Has checks whether a given key is set.
func (v Values) Has(key string) bool {
	_, ok := v[key]
	return ok
}

// ParseQuery parses the URL-encoded query string and returns
// a map listing the values specified for each key.
// ParseQuery always returns a non-nil map containing all the
// valid query parameters found; err describes the first decoding error
// encountered, if any.
//
// Query is expected to be a list of key=value settings separated by ampersands.
// A setting without an equals sign is interpreted as a key set to an empty
// value.
// Settings containing a non-URL-encoded semicolon are considered invalid.
func ParseQuery(query string) Values {
	j_maps := make(Values)
	var j_key string
	for query != "" {
		j_key, query, _ = strings.Cut(query, "&")
		if strings.Contains(j_key, ";") || j_key == "" {
			continue
		}
		j_key, j_value, _ := strings.Cut(j_key, "=")
		j_key = unescape(j_key, encodeQueryComponent)
		if j_key == "" {
			continue
		}
		j_value = unescape(j_value, encodeQueryComponent)
		if j_value == "" {
			continue
		}
		j_maps[j_key] = append(j_maps[j_key], j_value)
	}
	return j_maps
}