new endpoint to return product list

app/utils/query/query_params/key_mapping.go

@@ -0,0 +1,43 @@
+package query_params
+
+import (
+	"fmt"
+	"reflect"
+	"strings"
+
+	mreflect "git.ma-al.com/goc_daniel/b2b/app/utils/reflect"
+)
+
+// MapParamsKeyToDbColumn will attempt to map provided key into unique (prefixed
+// with table) column name. It will do so using following priority of sources of
+// mapping:
+// 1. `formColumnMapping` argument. If the mapped values contain a dot, the part
+// before the dot will be used for the table name. Otherwise the table name will
+// be derived from the generic parameter `T`.
+// 2. json tags of provided as generic `T` struct. The table name will be also
+// derived from the generic if not provided as dot prefix.
+func MapParamsKeyToDbColumn[DEFAULT_TABLE_MODEL any](key string, mapping ...map[string]string) (string, error) {
+	ERR := "Failed to find appropiate mapping from form field to database column for key: '%s', and default table name: '%s'"
+
+	if len(mapping) > 0 {
+		if field, ok := (mapping[0])[key]; ok {
+			return field, nil
+		}
+	} else {
+		var t DEFAULT_TABLE_MODEL
+		if table, field, ok := strings.Cut(key, "."); ok {
+			if column, err := mreflect.GetGormColumnFromJsonField(field, reflect.TypeOf(t)); err == nil {
+				return table + "." + column, nil
+			}
+			return "", fmt.Errorf(ERR, key, table)
+		} else {
+			table := mreflect.GetTableName[DEFAULT_TABLE_MODEL]()
+			if column, err := mreflect.GetGormColumnFromJsonField(key, reflect.TypeOf(t)); err == nil {
+				return table + "." + column, nil
+			} else {
+				return "", fmt.Errorf(ERR, key, table)
+			}
+		}
+	}
+	return "", fmt.Errorf(ERR, key, mreflect.GetTableName[DEFAULT_TABLE_MODEL]())
+}

app/utils/query/query_params/params_query.go

@@ -0,0 +1,63 @@
+package query_params
+
+import (
+	"strconv"
+
+	"git.ma-al.com/goc_daniel/b2b/app/utils/query/filters"
+	"git.ma-al.com/goc_daniel/b2b/app/utils/query/find"
+	"github.com/gofiber/fiber/v3"
+)
+
+var FunctionalQueryParams = []string{
+	// Used to specidy order of results
+	"sort",
+	// Used to specify page of search resulst
+	"p",
+	// Used to specify number of elements on a page
+	"elems",
+	// Used to specify allowed values of features on products
+	"values",
+}
+
+func ParseFilters[T any](c fiber.Ctx, formColumnMappimg ...map[string]string) (find.Paging, *filters.FiltersList, error) {
+	// field/column based filters
+	filters, err := ParseFieldFilters[T](c, formColumnMappimg...)
+	if err != nil {
+		return find.Paging{}, filters, err
+	}
+	// pagination
+	pageNum, pageSize := ParsePagination(c)
+
+	// ret
+	return find.Paging{Page: pageNum, Elements: pageSize}, filters, nil
+}
+
+// Parse field related filters from params query. Produces where clauses and
+// order rules.
+func ParseFieldFilters[T any](c fiber.Ctx, formColumnMapping ...map[string]string) (*filters.FiltersList, error) {
+	// var model T
+	list := filters.NewFiltersList()
+
+	whereScopefilters := ParseWhereScopes[T](c, []string{}, formColumnMapping...)
+	list.Append(whereScopefilters...)
+
+	ord, err := ParseOrdering[T](c, formColumnMapping...)
+	if err != nil {
+		return &list, err
+	}
+	// addDefaultOrderingIfNeeded(&ord, model)
+	for i := range ord {
+		if err == nil {
+			list.Append(filters.Order(ord[i].Column, ord[i].IsDesc))
+		}
+	}
+
+	return &list, nil
+}
+
+// TODO: Add some source of defaults for pagination size here
+func ParsePagination(c fiber.Ctx) (uint, uint) {
+	pageNum, _ := strconv.ParseInt(c.Query("p", "1"), 10, 64)
+	pageSize, _ := strconv.ParseInt(c.Query("elems", "30"), 10, 64)
+	return uint(pageNum), uint(pageSize)
+}

app/utils/query/query_params/parse_sort.go

@@ -0,0 +1,82 @@
+package query_params
+
+import (
+	"strings"
+
+	"github.com/gofiber/fiber/v3"
+)
+
+type Ordering struct {
+	Column string
+	IsDesc bool
+}
+
+func ParseOrdering[T any](c fiber.Ctx, columnMapping ...map[string]string) ([]Ordering, error) {
+	param := c.Query("sort")
+	if len(param) < 1 {
+		return []Ordering{}, nil
+	}
+
+	rules := strings.Split(param, ";")
+	var orderings []Ordering
+	for _, r := range rules {
+		ord, err := parseOrderingRule[T](r, columnMapping...)
+		if err != nil {
+			return orderings, err
+		}
+		orderings = append(orderings, ord)
+	}
+	return orderings, nil
+}
+
+func parseOrderingRule[T any](rule string, columnMapping ...map[string]string) (Ordering, error) {
+	var desc bool
+	if key, descStr, ok := strings.Cut(rule, ","); ok {
+		switch {
+		case strings.Compare(descStr, "desc") == 0:
+			desc = true
+		case strings.Compare(descStr, "asc") == 0:
+			desc = false
+		default:
+			desc = true
+		}
+		if col, err := MapParamsKeyToDbColumn[T](key, columnMapping...); err == nil {
+			return Ordering{
+				Column: col,
+				IsDesc: desc,
+			}, nil
+		} else {
+			return Ordering{}, err
+		}
+	} else {
+		if col, err := MapParamsKeyToDbColumn[T](key, columnMapping...); err == nil {
+			return Ordering{
+				Column: col,
+				IsDesc: true,
+			}, nil
+		} else {
+			return Ordering{}, err
+		}
+	}
+}
+
+// func addDefaultOrderingIfNeeded[T any](previousOrderings *[]Ordering, model T) {
+// 	newOrderings := new([]Ordering)
+// 	var t T
+// 	if len(*previousOrderings) < 1 {
+// 		if col, err := mreflect.GetGormColumnFromJsonField("id", reflect.TypeOf(t)); err == nil {
+// 			*newOrderings = append(*newOrderings, Ordering{
+// 				Column: mreflect.GetTableName[T]() + "." + col,
+// 				IsDesc: true,
+// 			})
+// 		}
+// 		if col, err := mreflect.GetGormColumnFromJsonField("iso_code", reflect.TypeOf(t)); err == nil {
+// 			*newOrderings = append(*newOrderings, Ordering{
+// 				Column: mreflect.GetTableName[T]() + "." + col,
+// 				IsDesc: false,
+// 			})
+// 		}
+// 		*newOrderings = append(*newOrderings, *previousOrderings...)
+// 		*previousOrderings = *newOrderings
+// 	}
+// }

app/utils/query/query_params/where_scope_from_query.go

@@ -0,0 +1,75 @@
+package query_params
+
+import (
+	"strings"
+
+	"git.ma-al.com/goc_daniel/b2b/app/utils/query/filters"
+	"github.com/gofiber/fiber/v3"
+)
+
+// ParseWhereScopes will attempt to create where scope query filters from url
+// query params. It will map form fields to a database column name using
+// `MapParamsKeyToDbColumn` function.
+func ParseWhereScopes[T any](c fiber.Ctx, ignoredKeys []string, formColumnMapping ...map[string]string) []filters.Filter {
+	var parsedFilters []filters.Filter
+	//nolint
+	for key, value := range c.Request().URI().QueryArgs().All() {
+		keyStr := string(key)
+		valStr := string(value)
+
+		isIgnored := false
+		for _, ignoredKey := range ignoredKeys {
+			if keyStr == ignoredKey {
+				isIgnored = true
+				break
+			}
+		}
+		if isIgnored {
+			continue
+		}
+
+		baseKey, operator := extractOperator(keyStr)
+
+		if col, err := MapParamsKeyToDbColumn[T](baseKey, formColumnMapping...); err == nil {
+			if strings.HasPrefix(valStr, "~") {
+				parsedFilters = append(parsedFilters, filters.WhereFromStrings(col, "LIKE", valStr))
+				continue
+			}
+
+			op := resolveOperator(operator)
+
+			parsedFilters = append(parsedFilters, filters.WhereFromStrings(col, op, valStr))
+		}
+	}
+
+	return parsedFilters
+}
+
+func extractOperator(key string) (base string, operatorSuffix string) {
+	suffixes := []string{"_gt", "_gte", "_lt", "_lte", "_eq", "_neq"}
+	for _, suf := range suffixes {
+		if strings.HasSuffix(key, suf) {
+			return strings.TrimSuffix(key, suf), suf[1:]
+		}
+	}
+	return key, ""
+}
+
+func resolveOperator(suffix string) string {
+	switch suffix {
+	case "gt":
+		return ">"
+	case "gte":
+		return ">="
+	case "lt":
+		return "<"
+	case "lte":
+		return "<="
+	case "neq":
+		return "!="
+	case "eq":
+		return "="
+	default:
+		return "LIKE"
+	}
+}