package qualify

import (
	"strings"
)

type Query map[string]Filter

type Filter []string

func (q Query) Query() string {
	if query, ok := q["query"]; ok {
		return strings.Join(query, " ")
	}
	return ""
}

func (f Filter) Last() string {
	return f[len(f)-1]
}

func Parse(text string, qualifiers ...string) Query {
	queries := make(map[string]Filter)

	for _, field := range fields(text) {
		var key, value string
		if k, v, ok := qualified(field, qualifiers...); ok {
			key = k
			value = trim(v)
		} else {
			key = "query"
			value = trim(field)
		}

		if queries[key] == nil {
			queries[key] = make([]string, 0)
		}
		queries[key] = append(queries[key], value)
	}

	return queries
}

func qualified(text string, qualifiers ...string) (string, string, bool) {
	if len(qualifiers) == 0 && strings.Contains(text, ":") {
		kv := strings.SplitN(text, ":", 2)
		return kv[0], kv[1], true
	}

	for _, qualifier := range qualifiers {
		if strings.HasPrefix(text, qualifier+":") {
			return text[:len(qualifier)], text[len(qualifier)+1:], true
		}
	}
	return "", "", false
}

func fields(text string) []string {
	var f []string

	var quotes bool
	var last int
	for idx, char := range text {
		if char == '"' {
			quotes = !quotes
			continue
		}

		if char == ' ' {
			if quotes {
				continue
			}
			f = append(f, text[last:idx])
			last = idx + 1
		}
	}
	f = append(f, strings.TrimSpace(text[last:]))
	return f
}

func trim(text string) string {
	return strings.TrimPrefix(strings.TrimSuffix(strings.TrimSpace(text), `"`), `"`)
}