/**
 * file: types/productSearch.go
 * author: Theo Technicguy
 * license: Apache 2.0
 *
 * product searching type and functions
 */

package types

import (
	"errors"
	"fmt"
	"strings"
)

var (
	ErrInvalidSearch = errors.New("invalid search")
)

type ProductSearch struct {
	Ean      string
	Names    []string
	TagIds   []uint
	Oprators ProductSearchOperators
}

type ProductSearchOperators struct {
	Master string
	Names  string
	TagIds string
}

/* *** Validators *** */

func (pso *ProductSearchOperators) ValidOperators() bool {
	return ((pso.Master == "AND" || pso.Master == "OR") &&
		(pso.Names == "AND" || pso.Names == "OR") &&
		(pso.TagIds == "AND" || pso.TagIds == "OR"))
}

func (pso *ProductSearchOperators) Valid() bool {
	return pso.ValidOperators()
}

func (ps *ProductSearch) Valid() bool {
	return ps.Oprators.Valid()
}

/* *** Type functions *** */

func (pso *ProductSearchOperators) FillDefaults() {
	if pso.Master == "" {
		pso.Master = "AND"
	}
	if pso.Names == "" {
		pso.Names = "AND"
	}
	if pso.TagIds == "" {
		pso.TagIds = "AND"
	}
}

func (ps *ProductSearch) BuildNamesSearch() string {
	nameSearch := []string{}
	for _, name := range ps.Names {
		nameSearch = append(nameSearch, fmt.Sprintf("p.name LIKE '%%%s%%'", name))
	}

	return "(" + strings.Join(nameSearch, " "+ps.Oprators.Names+" ") + ")"
}

func (ps *ProductSearch) BuildTagSearch() string {
	tagSearch := []string{}
	for _, tag := range ps.TagIds {
		tagSearch = append(tagSearch, fmt.Sprintf("%d", tag))
	}

	return "ptg.tid IN (" + strings.Join(tagSearch, ", ") + ")"
}

func (ps *ProductSearch) BuildSearch() string {
	sql := `SELECT DISTINCT p.*
	FROM Product p
	LEFT OUTER JOIN ProductTagging ptg ON p.ProductID = ptg.ProductID
	LEFT OUTER JOIN ProductTag pt ON ptg.TagID = pt.TagID
	`

	filters := []string{}

	if ps.Ean != "" {
		filters = append(filters, fmt.Sprintf("p.ean LIKE '%%%s%%'", ps.Ean))
	}
	if len(ps.Names) > 0 {
		filters = append(filters, ps.BuildNamesSearch())
	}
	if len(ps.TagIds) > 0 {
		filters = append(filters, ps.BuildTagSearch())
	}

	if len(filters) > 0 {
		sql = sql + "WHERE (" + strings.Join(filters, " "+ps.Oprators.Master+" ") + ")\n"
	}

	if len(ps.TagIds) > 0 {
		sql = sql + "GROUP BY p.id"
		if ps.Oprators.TagIds == "AND" {
			sql = sql + fmt.Sprintf("\nHAVING COUNT(p.id) = %d", len(ps.TagIds))
		}
	}

	sql = sql + ";"

	return sql
}