Add search engine support for files (#16190)

* Add search engine support for files

* Fixing i18n

* Fix golangci-lint

* Fix consistency problem in the Search receiver functio of the SqlFileStore

* Fixing some tests

* Fixing test

* Apply suggestions from code review

Co-authored-by: Mario de Frutos Dieguez <mario@defrutos.org>

* Addressing PR review comments

* Removing some empty lines

* Address PR review comments

* Fixing problem after merge master

* Fixing spelling problem

* Add missed translations

* Fixing certain global variable usages after merge master

* Fixing some constants usage

* Fixing goimports order

Co-authored-by: Mario de Frutos Dieguez <mario@defrutos.org>

model/search_params.go

@@ -25,6 +25,8 @@ type SearchParams struct {
 	ExcludedAfterDate      string
 	BeforeDate             string
 	ExcludedBeforeDate     string
+	Extensions             []string
+	ExcludedExtensions     []string
 	OnDate                 string
 	ExcludedDate           string
 	OrTerms                bool
@@ -106,7 +108,7 @@ func (p *SearchParams) GetExcludedDateMillis() (int64, int64) {
 	return GetStartOfDayMillis(date, p.TimeZoneOffset), GetEndOfDayMillis(date, p.TimeZoneOffset)
 }
 
-var searchFlags = [...]string{"from", "channel", "in", "before", "after", "on"}
+var searchFlags = [...]string{"from", "channel", "in", "before", "after", "on", "ext"}
 
 type flag struct {
 	name    string
@@ -265,6 +267,8 @@ func ParseSearchParams(text string, timeZoneOffset int) []*SearchParams {
 	excludedBeforeDate := ""
 	onDate := ""
 	excludedDate := ""
+	excludedExtensions := []string{}
+	extensions := []string{}
 
 	for _, flag := range flags {
 		if flag.name == "in" || flag.name == "channel" {
@@ -297,6 +301,12 @@ func ParseSearchParams(text string, timeZoneOffset int) []*SearchParams {
 			} else {
 				onDate = flag.value
 			}
+		} else if flag.name == "ext" {
+			if flag.exclude {
+				excludedExtensions = append(excludedExtensions, flag.value)
+			} else {
+				extensions = append(extensions, flag.value)
+			}
 		}
 	}
 
@@ -315,6 +325,8 @@ func ParseSearchParams(text string, timeZoneOffset int) []*SearchParams {
 			ExcludedAfterDate:  excludedAfterDate,
 			BeforeDate:         beforeDate,
 			ExcludedBeforeDate: excludedBeforeDate,
+			Extensions:         extensions,
+			ExcludedExtensions: excludedExtensions,
 			OnDate:             onDate,
 			ExcludedDate:       excludedDate,
 			TimeZoneOffset:     timeZoneOffset,
@@ -334,6 +346,8 @@ func ParseSearchParams(text string, timeZoneOffset int) []*SearchParams {
 			ExcludedAfterDate:  excludedAfterDate,
 			BeforeDate:         beforeDate,
 			ExcludedBeforeDate: excludedBeforeDate,
+			Extensions:         extensions,
+			ExcludedExtensions: excludedExtensions,
 			OnDate:             onDate,
 			ExcludedDate:       excludedDate,
 			TimeZoneOffset:     timeZoneOffset,
@@ -345,6 +359,7 @@ func ParseSearchParams(text string, timeZoneOffset int) []*SearchParams {
 		len(excludedPlainTerms) == 0 && len(excludedHashtagTerms) == 0 &&
 		(len(inChannels) != 0 || len(fromUsers) != 0 ||
 			len(excludedChannels) != 0 || len(excludedUsers) != 0 ||
+			len(extensions) != 0 || len(excludedExtensions) != 0 ||
 			afterDate != "" || excludedAfterDate != "" ||
 			beforeDate != "" || excludedBeforeDate != "" ||
 			onDate != "" || excludedDate != "") {
@@ -360,6 +375,8 @@ func ParseSearchParams(text string, timeZoneOffset int) []*SearchParams {
 			ExcludedAfterDate:  excludedAfterDate,
 			BeforeDate:         beforeDate,
 			ExcludedBeforeDate: excludedBeforeDate,
+			Extensions:         extensions,
+			ExcludedExtensions: excludedExtensions,
 			OnDate:             onDate,
 			ExcludedDate:       excludedDate,
 			TimeZoneOffset:     timeZoneOffset,