package whois

import (
	"encoding/json"
	"fmt"
	"strings"
)

type rdapDomainDoc struct {
	ObjectClassName string           `json:"objectClassName"`
	LDHName         string           `json:"ldhName"`
	UnicodeName     string           `json:"unicodeName"`
	Handle          string           `json:"handle"`
	Status          []string         `json:"status"`
	Nameservers     []rdapNameServer `json:"nameservers"`
	Events          []rdapEvent      `json:"events"`
	Entities        []rdapEntityDoc  `json:"entities"`
}

type rdapNameServer struct {
	LDHName     string `json:"ldhName"`
	UnicodeName string `json:"unicodeName"`
}

type rdapEvent struct {
	EventAction string `json:"eventAction"`
	EventDate   string `json:"eventDate"`
}

type rdapEntityDoc struct {
	Handle    string         `json:"handle"`
	Roles     []string       `json:"roles"`
	PublicIDs []rdapPublicID `json:"publicIds"`
	VCard     any            `json:"vcardArray"`
}

type rdapPublicID struct {
	Type       string `json:"type"`
	Identifier string `json:"identifier"`
}

func rdapResponseToResult(query string, resp *RDAPResponse, targetKind lookupTargetKind) (Result, error) {
	if resp == nil {
		return Result{}, fmt.Errorf("whois/rdap: nil response")
	}
	var doc rdapDomainDoc
	if err := json.Unmarshal(resp.Body, &doc); err != nil {
		return Result{}, fmt.Errorf("whois/rdap: decode domain response failed: %w", err)
	}

	normalizedQuery := strings.TrimSpace(query)
	if targetKind == lookupTargetDomain {
		normalizedQuery = strings.ToLower(strings.Trim(normalizedQuery, "."))
	}
	result := Result{
		exists:   false,
		domain:   normalizedQuery,
		rawData:  string(resp.Body),
		whoisSer: resp.Endpoint,
	}

	switch targetKind {
	case lookupTargetDomain:
		if n := strings.TrimSpace(doc.LDHName); n != "" {
			result.domain = strings.ToLower(n)
			result.exists = true
		} else if n := strings.TrimSpace(doc.UnicodeName); n != "" {
			result.domain = n
			result.exists = true
		}
		if strings.EqualFold(strings.TrimSpace(doc.ObjectClassName), "domain") {
			result.exists = true
		}
	case lookupTargetIP, lookupTargetASN:
		if strings.TrimSpace(doc.ObjectClassName) != "" || strings.TrimSpace(doc.Handle) != "" {
			result.exists = true
		}
		if result.domain == "" {
			result.domain = normalizedQuery
		}
	}
	if h := strings.TrimSpace(doc.Handle); h != "" {
		result.domainID = h
	}

	result.statusRaw = appendUniqueStrings(result.statusRaw, normalizeStringSlice(doc.Status)...)
	for _, ns := range doc.Nameservers {
		v := strings.TrimSpace(ns.LDHName)
		if v == "" {
			v = strings.TrimSpace(ns.UnicodeName)
		}
		if v != "" {
			result.nsServers = appendUniqueStrings(result.nsServers, v)
		}
	}

	for _, ev := range doc.Events {
		action := strings.ToLower(strings.TrimSpace(ev.EventAction))
		if action == "" {
			continue
		}
		t := parseDateAuto(strings.TrimSpace(ev.EventDate))
		if t.IsZero() {
			continue
		}
		switch {
		case strings.Contains(action, "registration"),
			strings.Contains(action, "registered"),
			strings.Contains(action, "creation"):
			if !result.hasRegisterDate {
				result.hasRegisterDate = true
				result.registerDate = t
			}
		case strings.Contains(action, "expiration"),
			strings.Contains(action, "expiry"),
			strings.Contains(action, "expire"):
			if !result.hasExpireDate {
				result.hasExpireDate = true
				result.expireDate = t
			}
		case strings.Contains(action, "changed"),
			strings.Contains(action, "update"):
			if !result.hasUpdateDate {
				result.hasUpdateDate = true
				result.updateDate = t
			}
		}
	}

	for _, ent := range doc.Entities {
		info := parseRDAPEntityPersonalInfo(ent.VCard)
		isRegistrar, isRegistrant, isAdmin, isTech := classifyRDAPEntityRoles(ent.Roles)

		if isRegistrar {
			if result.registrar == "" {
				result.registrar = firstNonEmpty(info.Org, info.Name, ent.Handle)
			}
			if result.ianaID == "" {
				for _, pid := range ent.PublicIDs {
					typed := strings.ToLower(strings.TrimSpace(pid.Type))
					if strings.Contains(typed, "iana") {
						result.ianaID = strings.TrimSpace(pid.Identifier)
						break
					}
				}
			}
		}
		if isRegistrant {
			result.registerInfo = mergePersonalInfo(result.registerInfo, info)
		}
		if isAdmin {
			result.adminInfo = mergePersonalInfo(result.adminInfo, info)
		}
		if isTech {
			result.techInfo = mergePersonalInfo(result.techInfo, info)
		}
	}

	result.meta = buildResultMeta(result, "rdap", resp.Endpoint)
	result.meta.Charset = "utf-8"
	return result, nil
}

func parseRDAPEntityPersonalInfo(vcard any) PersonalInfo {
	info := PersonalInfo{}
	root, ok := vcard.([]any)
	if !ok || len(root) < 2 {
		return info
	}
	props, ok := root[1].([]any)
	if !ok {
		return info
	}

	for _, p := range props {
		kv, ok := p.([]any)
		if !ok || len(kv) < 4 {
			continue
		}
		key := strings.ToLower(strings.TrimSpace(fmt.Sprint(kv[0])))
		val := kv[3]
		switch key {
		case "fn":
			info.Name = firstNonEmpty(info.Name, rdapValueString(val))
		case "org":
			info.Org = firstNonEmpty(info.Org, rdapValueString(val))
		case "email":
			info.Email = firstNonEmpty(info.Email, rdapValueString(val))
		case "tel":
			info.Phone = firstNonEmpty(info.Phone, rdapValueString(val))
		case "adr":
			addr, city, state, zip, country := rdapAddressFields(val)
			info.Addr = firstNonEmpty(info.Addr, addr)
			info.City = firstNonEmpty(info.City, city)
			info.State = firstNonEmpty(info.State, state)
			info.Zip = firstNonEmpty(info.Zip, zip)
			info.Country = firstNonEmpty(info.Country, country)
		}
	}
	return info
}

func rdapAddressFields(v any) (addr, city, state, zip, country string) {
	arr, ok := v.([]any)
	if !ok {
		return rdapValueString(v), "", "", "", ""
	}
	get := func(i int) string {
		if i < 0 || i >= len(arr) {
			return ""
		}
		return strings.TrimSpace(rdapValueString(arr[i]))
	}
	addr = strings.TrimSpace(strings.Join(compactStrings([]string{get(0), get(1), get(2)}), " "))
	city = get(3)
	state = get(4)
	zip = get(5)
	country = get(6)
	return
}

func rdapValueString(v any) string {
	switch x := v.(type) {
	case string:
		return strings.TrimSpace(x)
	case []any:
		parts := make([]string, 0, len(x))
		for _, item := range x {
			s := strings.TrimSpace(rdapValueString(item))
			if s != "" {
				parts = append(parts, s)
			}
		}
		return strings.Join(parts, " ")
	default:
		return strings.TrimSpace(fmt.Sprint(v))
	}
}

func classifyRDAPEntityRoles(roles []string) (isRegistrar, isRegistrant, isAdmin, isTech bool) {
	for _, role := range roles {
		r := strings.ToLower(strings.TrimSpace(role))
		switch {
		case strings.Contains(r, "registrar"):
			isRegistrar = true
		case strings.Contains(r, "registrant"), strings.Contains(r, "holder"):
			isRegistrant = true
		case strings.Contains(r, "administrative"), strings.Contains(r, "admin"):
			isAdmin = true
		case strings.Contains(r, "technical"), strings.Contains(r, "tech"):
			isTech = true
		}
	}
	return
}

func normalizeStringSlice(in []string) []string {
	out := make([]string, 0, len(in))
	seen := make(map[string]struct{}, len(in))
	for _, v := range in {
		v = strings.TrimSpace(v)
		if v == "" {
			continue
		}
		if _, ok := seen[v]; ok {
			continue
		}
		seen[v] = struct{}{}
		out = append(out, v)
	}
	return out
}

func compactStrings(in []string) []string {
	out := make([]string, 0, len(in))
	for _, s := range in {
		s = strings.TrimSpace(s)
		if s != "" {
			out = append(out, s)
		}
	}
	return out
}

func firstNonEmpty(values ...string) string {
	for _, v := range values {
		if strings.TrimSpace(v) != "" {
			return strings.TrimSpace(v)
		}
	}
	return ""
}