platform: modularize api/gui, add docs-tests-web foundation, and refresh root config

selective-vpn-api/app/vpn_locations_selection.go

@@ -0,0 +1,164 @@
+package app
+
+import (
+	"fmt"
+	"strings"
+)
+
+type vpnLocationChoice struct {
+	ISO       string
+	Label     string
+	RawTarget string
+	Name      string
+	Connect   string
+}
+
+func resolveVPNLocationSelection(
+	reqTarget string,
+	reqISO string,
+	reqLabel string,
+	locs []vpnLocationItem,
+) (target string, iso string, label string, validated bool, err error) {
+	targetReq := strings.TrimSpace(reqTarget)
+	isoReq := strings.ToUpper(strings.TrimSpace(reqISO))
+	labelReq := strings.TrimSpace(reqLabel)
+
+	choices := buildVPNLocationChoices(locs)
+	if len(choices) == 0 {
+		if isISO2(isoReq) {
+			return isoReq, isoReq, "", false, nil
+		}
+		if isISO2(targetReq) {
+			t := strings.ToUpper(strings.TrimSpace(targetReq))
+			return t, t, "", false, nil
+		}
+		return "", "", "", false, fmt.Errorf("location catalog unavailable; use ISO code")
+	}
+
+	findBy := func(pred func(vpnLocationChoice) bool) *vpnLocationChoice {
+		for i := range choices {
+			if pred(choices[i]) {
+				return &choices[i]
+			}
+		}
+		return nil
+	}
+
+	var chosen *vpnLocationChoice
+
+	if labelReq != "" {
+		chosen = findBy(func(it vpnLocationChoice) bool {
+			return equalsFoldTrim(labelReq, it.Label)
+		})
+	}
+
+	if chosen == nil && targetReq != "" {
+		chosen = findBy(func(it vpnLocationChoice) bool {
+			return equalsFoldTrim(targetReq, it.Connect) ||
+				equalsFoldTrim(targetReq, it.Name) ||
+				equalsFoldTrim(targetReq, it.RawTarget) ||
+				equalsFoldTrim(targetReq, it.Label)
+		})
+	}
+
+	if chosen == nil && isISO2(isoReq) {
+		chosen = findBy(func(it vpnLocationChoice) bool {
+			return it.ISO == isoReq
+		})
+	}
+
+	if chosen == nil && isISO2(targetReq) {
+		isoByTarget := strings.ToUpper(strings.TrimSpace(targetReq))
+		chosen = findBy(func(it vpnLocationChoice) bool {
+			return it.ISO == isoByTarget
+		})
+	}
+
+	if chosen == nil {
+		return "", "", "", false, fmt.Errorf("location not recognized; current connection kept")
+	}
+
+	connectArg := strings.TrimSpace(chosen.Connect)
+	if connectArg == "" {
+		connectArg = chosen.ISO
+	}
+
+	isValidated := true
+	if targetReq != "" &&
+		!equalsFoldTrim(targetReq, connectArg) &&
+		!equalsFoldTrim(targetReq, chosen.ISO) &&
+		!equalsFoldTrim(targetReq, chosen.Name) &&
+		!equalsFoldTrim(targetReq, chosen.RawTarget) &&
+		!equalsFoldTrim(targetReq, chosen.Label) {
+		isValidated = false
+	}
+
+	return connectArg, chosen.ISO, chosen.Label, isValidated, nil
+}
+
+func buildVPNLocationChoices(locs []vpnLocationItem) []vpnLocationChoice {
+	choices := make([]vpnLocationChoice, 0, len(locs))
+	namesByISO := map[string][][]string{}
+	countByISO := map[string]int{}
+
+	for _, it := range locs {
+		iso := strings.ToUpper(strings.TrimSpace(it.ISO))
+		if !isISO2(iso) {
+			continue
+		}
+		label := strings.TrimSpace(it.Label)
+		rawTarget := strings.TrimSpace(it.Target)
+
+		name := inferVPNLocationTargetFromLabel(label, iso)
+		if name == "" {
+			name = rawTarget
+		}
+		if name == "" {
+			name = iso
+		}
+
+		namesByISO[iso] = append(namesByISO[iso], strings.Fields(name))
+		countByISO[iso]++
+		choices = append(choices, vpnLocationChoice{
+			ISO:       iso,
+			Label:     label,
+			RawTarget: rawTarget,
+			Name:      name,
+		})
+	}
+
+	commonByISO := map[string][]string{}
+	for iso, names := range namesByISO {
+		if len(names) < 2 {
+			continue
+		}
+		pfx := commonPrefixTokens(names)
+		if len(pfx) > 0 {
+			commonByISO[iso] = pfx
+		}
+	}
+
+	for i := range choices {
+		iso := choices[i].ISO
+		if countByISO[iso] <= 1 {
+			choices[i].Connect = iso
+			continue
+		}
+		tokens := strings.Fields(choices[i].Name)
+		pfx := commonByISO[iso]
+		if len(pfx) > 0 && len(tokens) > len(pfx) {
+			choices[i].Connect = strings.TrimSpace(strings.Join(tokens[len(pfx):], " "))
+		} else if choices[i].Name != "" {
+			choices[i].Connect = choices[i].Name
+		}
+		if choices[i].Connect == "" {
+			choices[i].Connect = iso
+		}
+	}
+
+	return choices
+}
+
+func equalsFoldTrim(a, b string) bool {
+	return strings.EqualFold(strings.TrimSpace(a), strings.TrimSpace(b))
+}