package app

import (
	transportcfgpkg "selective-vpn-api/app/transportcfg"
	"sort"
	"strconv"
	"strings"
)

func deriveSingBoxProfileID(name, protocol string, existing []SingBoxProfile) string {
	base := sanitizeID(name)
	if base == "" {
		base = sanitizeID(protocol)
	}
	if base == "" {
		base = "singbox-profile"
	}
	cand := base

	used := make(map[string]struct{}, len(existing))
	for _, it := range existing {
		used[it.ID] = struct{}{}
	}
	if _, ok := used[cand]; !ok {
		return cand
	}
	for i := 2; i < 1000; i++ {
		v := base + "-" + strconv.Itoa(i)
		if _, ok := used[v]; !ok {
			return v
		}
	}
	return ""
}

func findSingBoxProfileIndex(items []SingBoxProfile, id string) int {
	for i := range items {
		if strings.TrimSpace(items[i].ID) == id {
			return i
		}
	}
	return -1
}

func ensureSingBoxProfilesActiveID(st *singBoxProfilesState) {
	if st == nil {
		return
	}
	if len(st.Items) == 0 {
		st.ActiveProfileID = ""
		return
	}
	active := strings.TrimSpace(st.ActiveProfileID)
	if active != "" {
		for _, it := range st.Items {
			if it.ID == active && it.Enabled {
				return
			}
		}
	}
	for _, it := range st.Items {
		if it.Enabled {
			st.ActiveProfileID = it.ID
			return
		}
	}
	st.ActiveProfileID = st.Items[0].ID
}

func normalizeSingBoxProfilesState(in singBoxProfilesState) singBoxProfilesState {
	out := in
	if out.Version == 0 {
		out.Version = singBoxProfilesStateVersion
	}
	if out.Revision < 0 {
		out.Revision = 0
	}

	byID := map[string]SingBoxProfile{}
	for _, raw := range in.Items {
		it := normalizeSingBoxProfile(raw)
		if it.ID == "" {
			continue
		}
		cur, ok := byID[it.ID]
		if !ok || preferSingBoxProfile(it, cur) {
			byID[it.ID] = it
		}
	}
	keys := make([]string, 0, len(byID))
	for id := range byID {
		keys = append(keys, id)
	}
	sort.Strings(keys)

	out.Items = make([]SingBoxProfile, 0, len(keys))
	for _, id := range keys {
		out.Items = append(out.Items, byID[id])
	}
	ensureSingBoxProfilesActiveID(&out)
	return out
}

func normalizeSingBoxProfile(in SingBoxProfile) SingBoxProfile {
	out := in
	out.ID = sanitizeID(in.ID)
	if out.ID == "" {
		return SingBoxProfile{}
	}
	out.Name = strings.TrimSpace(in.Name)
	if out.Name == "" {
		out.Name = out.ID
	}
	if mode, ok := normalizeSingBoxProfileMode(in.Mode); ok {
		out.Mode = mode
	} else {
		out.Mode = SingBoxProfileModeTyped
	}
	out.Protocol = normalizeSingBoxProtocol(in.Protocol)
	out.SchemaVersion = normalizeSingBoxSchemaVersion(in.SchemaVersion)
	if out.ProfileRevision <= 0 {
		out.ProfileRevision = 1
	}
	if out.RenderRevision < 0 {
		out.RenderRevision = 0
	}
	out.LastValidatedAt = strings.TrimSpace(in.LastValidatedAt)
	out.LastAppliedAt = strings.TrimSpace(in.LastAppliedAt)
	out.LastError = strings.TrimSpace(in.LastError)
	out.CreatedAt = strings.TrimSpace(in.CreatedAt)
	out.UpdatedAt = strings.TrimSpace(in.UpdatedAt)
	out.Typed = cloneMapDeep(in.Typed)
	out.RawConfig = cloneMapDeep(in.RawConfig)
	out.Meta = cloneMapDeep(in.Meta)

	secretMap, err := readSingBoxSecrets(out.ID)
	if err == nil {
		out.HasSecrets = len(secretMap) > 0
		out.SecretsMasked = transportcfgpkg.MaskStringMap(secretMap, "******")
	} else {
		out.HasSecrets = in.HasSecrets
		out.SecretsMasked = transportcfgpkg.CloneStringMap(in.SecretsMasked)
	}
	if !out.HasSecrets {
		out.SecretsMasked = nil
	}
	return out
}

func preferSingBoxProfile(cand, cur SingBoxProfile) bool {
	if cand.ProfileRevision != cur.ProfileRevision {
		return cand.ProfileRevision > cur.ProfileRevision
	}
	cu := strings.TrimSpace(cand.UpdatedAt)
	ou := strings.TrimSpace(cur.UpdatedAt)
	if cu != ou {
		if cu == "" {
			return false
		}
		if ou == "" {
			return true
		}
		return cu > ou
	}
	return strings.TrimSpace(cand.CreatedAt) > strings.TrimSpace(cur.CreatedAt)
}