package httpapi

import (
	"bytes"
	"crypto/rand"
	"encoding/hex"
	"encoding/json"
	"errors"
	"net/http"
	"strings"
	"time"

	"evobgp/internal/nodedispatch"
	"evobgp/internal/speakerinstall"
	"evobgp/internal/store"
)

var errSpeakerMetaJSONType = errors.New("meta_json must be a JSON object or string")

type speakerCreateRequest struct {
	Role             string          `json:"role"`
	Endpoint         string          `json:"endpoint"`
	MetaJSON         json.RawMessage `json:"meta_json"`
	LetsEncryptEmail string          `json:"letsencrypt_email"`
	CFDNSAPIToken    string          `json:"cf_dns_api_token"`
	PanelIPWhitelist string          `json:"panel_ip_whitelist"`
	ControlPlaneURL  string          `json:"control_plane_url"`
}

func speakerJSONFromStore(st store.Backend, sp *store.Speaker) map[string]any {
	if sp == nil {
		return map[string]any{}
	}
	meta := store.ParseSpeakerMeta(sp.MetaJSON)
	m := map[string]any{
		"id":       sp.ID,
		"role":     sp.Role,
		"endpoint": sp.Endpoint,
	}
	if sp.LastAppliedRevisionID != nil {
		m["last_applied_revision_id"] = *sp.LastAppliedRevisionID
	} else {
		m["last_applied_revision_id"] = nil
	}
	if st != nil {
		if rid, at, err := st.LatestPublishedRevision(sp.ID); err == nil && rid != "" {
			m["published_revision_id"] = rid
			m["published_at"] = at.UTC().Format(time.RFC3339Nano)
		} else {
			m["published_revision_id"] = nil
			m["published_at"] = nil
		}
	}
	if strings.TrimSpace(sp.MetaJSON) != "" && sp.MetaJSON != "{}" {
		var raw map[string]any
		if json.Unmarshal([]byte(sp.MetaJSON), &raw) == nil {
			delete(raw, "agent_secret")
			if len(raw) > 0 {
				m["meta_json"] = raw
			}
		}
	}
	if meta.AgentDomain != "" {
		m["agent_domain"] = meta.AgentDomain
	}
	if meta.NodeIPv4 != "" {
		m["node_ipv4"] = meta.NodeIPv4
	}
	if meta.BirdBgpSourceIPv4 != "" {
		m["bird_bgp_source_ipv4"] = meta.BirdBgpSourceIPv4
	}
	if meta.LastDispatchAt != "" {
		m["last_dispatch_at"] = meta.LastDispatchAt
	}
	if meta.LastDispatchError != "" {
		m["last_dispatch_error"] = meta.LastDispatchError
	}
	if meta.LastDispatchStatus != "" {
		m["dispatch_status"] = meta.LastDispatchStatus
	}
	if meta.SyncStatus != "" {
		m["sync_status"] = meta.SyncStatus
	}
	return m
}

func (s *Server) handleBundleSigningPublicKey(w http.ResponseWriter, r *http.Request) {
	a, ok := authFromContext(r.Context())
	if !ok || !s.requirePerm(w, a, "bgp:network:read") {
		return
	}
	writeJSON(w, http.StatusOK, map[string]any{
		"public_key_base64": s.BundlePublicKeyBase64(),
	})
}

// normalizeSpeakerCreate fills meta defaults and validates replica fields.
func normalizeSpeakerCreate(in *store.Speaker) error {
	if in == nil {
		return store.ErrInvalidInput
	}
	meta := store.ParseSpeakerMeta(in.MetaJSON)
	if meta.AgentSecret == "" {
		b := make([]byte, 24)
		if _, err := rand.Read(b); err != nil {
			return err
		}
		meta.AgentSecret = hex.EncodeToString(b)
	}
	if meta.AgentPort == 0 {
		meta.AgentPort = 8443
	}
	if meta.NodeIPv4 == "" {
		meta.NodeIPv4 = store.IPv4FromEndpoint(in.Endpoint)
	}
	if meta.BirdBgpSourceIPv4 == "" && meta.NodeIPv4 != "" {
		meta.BirdBgpSourceIPv4 = meta.NodeIPv4
	}
	if meta.BirdBgpSourceIPv4 != "" && !store.ValidIPv4(meta.BirdBgpSourceIPv4) {
		return store.ErrInvalidInput
	}
	if meta.AgentDomain == "" && in.Endpoint != "" {
		ep := strings.TrimSpace(in.Endpoint)
		if strings.HasPrefix(ep, "https://") {
			u := strings.TrimPrefix(ep, "https://")
			if idx := strings.Index(u, "/"); idx >= 0 {
				u = u[:idx]
			}
			if idx := strings.Index(u, ":"); idx >= 0 {
				u = u[:idx]
			}
			if u != "" && !store.ValidIPv4(u) {
				meta.AgentDomain = u
			}
		}
	}
	in.MetaJSON = store.SpeakerMetaJSON(meta)
	return nil
}

func metaJSONRawToString(raw json.RawMessage) (string, error) {
	t := bytes.TrimSpace(raw)
	if len(t) == 0 {
		return "{}", nil
	}
	switch t[0] {
	case '"':
		var s string
		if err := json.Unmarshal(t, &s); err != nil {
			return "", err
		}
		s = strings.TrimSpace(s)
		if s == "" {
			return "{}", nil
		}
		return s, nil
	case '{':
		return string(t), nil
	default:
		return "", errSpeakerMetaJSONType
	}
}

func publicControlPlaneURL(r *http.Request, override string) string {
	if s := strings.TrimSpace(override); s != "" {
		return strings.TrimRight(s, "/")
	}
	if origin := strings.TrimSpace(r.Header.Get("Origin")); strings.HasPrefix(origin, "http://") || strings.HasPrefix(origin, "https://") {
		return strings.TrimRight(origin, "/")
	}
	proto := strings.TrimSpace(r.Header.Get("X-Forwarded-Proto"))
	if proto == "" {
		proto = "https"
	}
	host := strings.TrimSpace(r.Header.Get("X-Forwarded-Host"))
	if i := strings.Index(host, ","); i >= 0 {
		host = strings.TrimSpace(host[:i])
	}
	if host == "" {
		host = strings.TrimSpace(r.Host)
	}
	if host == "" {
		return ""
	}
	return proto + "://" + host
}

func (s *Server) attachReplicaInstall(resp map[string]any, sp *store.Speaker, nodeToken string, req speakerCreateRequest, r *http.Request) {
	if s == nil || sp == nil || resp == nil {
		return
	}
	meta := store.ParseSpeakerMeta(sp.MetaJSON)
	built, err := speakerinstall.Build(speakerinstall.Params{
		SpeakerID:        sp.ID,
		AgentSecret:      meta.AgentSecret,
		NodeToken:        nodeToken,
		BundlePubkey:     s.BundlePublicKeyBase64(),
		ControlPlaneURL:  publicControlPlaneURL(r, req.ControlPlaneURL),
		AgentDomain:      meta.AgentDomain,
		LetsEncryptEmail: req.LetsEncryptEmail,
		CFDNSAPIToken:    req.CFDNSAPIToken,
		PanelIPWhitelist: req.PanelIPWhitelist,
	})
	if err != nil {
		return
	}
	resp["bundle_pubkey_base64"] = s.BundlePublicKeyBase64()
	resp["install"] = map[string]any{
		"docker_commands": built.DockerCommands,
		"compose_yaml":    built.ComposeYAML,
	}
}

func (s *Server) recordSpeakerDispatch(tenantID string, sp *store.Speaker, res nodedispatch.Result) {
	if s == nil || s.store == nil || sp == nil {
		return
	}
	patch := store.SpeakerMeta{
		LastDispatchAt:     time.Now().UTC().Format(time.RFC3339Nano),
		LastDispatchStatus: res.Status,
	}
	if res.Error != "" {
		patch.LastDispatchError = res.Error
		patch.SyncStatus = "error"
	} else if res.Status == "ok" {
		patch.LastDispatchError = ""
		patch.SyncStatus = "synced"
	}
	meta := store.MergeSpeakerMetaJSON(sp.MetaJSON, patch)
	_, _ = s.store.UpdateSpeaker(tenantID, sp.ID, &store.SpeakerPatch{MetaJSON: &meta})
}