package sqimple

import (
	"fmt"
	"regexp"
	"strings"
)

var selectTableRegexp = regexp.MustCompile("^(from|left join|inner join|right join) ([^ ]+)( (as) ([^ ]+))?( (on) ([^ ]+) (=|!=|>|>=|<|<=) ([^ ]+)( (and) ([^ ]+) (=|!=|>|>=|<|<=) ([^ ]+))*)?$")

type SelectTable string

func (t SelectTable) IsValid() bool {
	return selectTableRegexp.MatchString(string(t))
}

func (t SelectTable) Parse() (selectType, table, as string, on *OnClause, ok bool) {
	if selectTableRegexp.MatchString(string(t)) {
		ok = true

		result := selectTableRegexp.FindAllStringSubmatch(string(t), -1)

		for i, r := range result {
			// for j, c := range r {
			// 	fmt.Println(i, j, c)
			// }

			if i == 0 {
				selectType, table = r[1], r[2]

				if r[4] == "as" {
					as = r[5]
				}

				if r[7] == "on" {
					on = On(r[8], r[9], r[10])
				}
			}

			if r[12] == "and" {
				on.And(r[13], r[14], r[15])
			}
		}
	}

	return
}

func (t SelectTable) String() string {
	return string(t)
}

func From(def string) SelectTable {
	if strings.Index(def, "from ") == 0 {
		return SelectTable(def)
	}

	return SelectTable(fmt.Sprintf("from %s", def))
}

func InnerJoin(def string) SelectTable {
	if strings.Index(def, "inner join ") == 0 {
		return SelectTable(def)
	}

	return SelectTable(fmt.Sprintf("inner join %s", def))
}

func LeftJoin(def string) SelectTable {
	if strings.Index(def, "left join ") == 0 {
		return SelectTable(def)
	}

	return SelectTable(fmt.Sprintf("left join %s", def))
}

func RightJoin(def string) SelectTable {
	if strings.Index(def, "right join ") == 0 {
		return SelectTable(def)
	}

	return SelectTable(fmt.Sprintf("right join %s", def))
}