package gateway

import (
	"context"
	"encoding/json"
	"errors"
	"net/http"
	"strconv"
	"strings"
	"time"

	"git.yeij.top/AskaEth/Cyrene_v2/internal/auth"
	capreg "git.yeij.top/AskaEth/Cyrene_v2/internal/capability/registry"
	apperr "git.yeij.top/AskaEth/Cyrene_v2/internal/errors"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/knowledge"
	"git.yeij.top/AskaEth/Cyrene_v2/pkg/plugins/sdk"
)

// backthinkListLimit is the number of most-recent think records the admin
// panel asks for when no limit is specified.
const backthinkListLimit = 50

// PluginSummary is the wire shape of a capability/plugin in the admin list.
type PluginSummary struct {
	Name            string `json:"name"`
	Kind            string `json:"kind"`
	Description     string `json:"description"`
	AllowInGroup    bool   `json:"allowInGroup"`
	AllowInStranger bool   `json:"allowInStranger"`
}

// ChannelSummary is the wire shape of a registered channel adapter.
type ChannelSummary struct {
	Name      string `json:"name"`
	Connected bool   `json:"connected"`
}

// policyRequest is the POST /api/v1/admin/plugins/policy body.
type policyRequest struct {
	Name            string `json:"name"`
	AllowInGroup    bool   `json:"allowInGroup"`
	AllowInStranger bool   `json:"allowInStranger"`
}

// AdminLlmProvider is the wire shape of one LLM provider in the admin config.
// The API key is deliberately absent: it is never returned to the client.
type AdminLlmProvider struct {
	ID         string `json:"id"`
	Name       string `json:"name"`
	BaseURL    string `json:"baseUrl"`
	Model      string `json:"model"`
	Multimodal bool   `json:"multimodal"`
	Enabled    bool   `json:"enabled"`
	Fallback   string `json:"fallback,omitempty"`
}

// AdminLlmConfig is the wire shape of GET /api/v1/admin/llm.
type AdminLlmConfig struct {
	Providers []AdminLlmProvider `json:"providers"`
}

// AdminAutomationRecord is the wire shape of one automation/reminder in the
// admin list. Cron carries the cron expression for the cron kind; lastRun and
// nextRun are omitted when the value is unknown.
type AdminAutomationRecord struct {
	ID      string `json:"id"`
	Name    string `json:"name"`
	Kind    string `json:"kind"`
	Cron    string `json:"cron,omitempty"`
	Enabled bool   `json:"enabled"`
	LastRun string `json:"lastRun,omitempty"`
	NextRun string `json:"nextRun,omitempty"`
}

// AdminUserRecord is the wire shape of one account/API key in the admin list.
type AdminUserRecord struct {
	ID        string `json:"id"`
	Username  string `json:"username"`
	Role      string `json:"role"`
	CreatedAt string `json:"createdAt,omitempty"`
}

// AdminBackthinkItem is the wire shape of one background-think record in the
// admin monitor list.
type AdminBackthinkItem struct {
	ID           string `json:"id"`
	Trigger      string `json:"trigger"`
	Conclusion   string `json:"conclusion,omitempty"`
	ShouldNotify bool   `json:"shouldNotify"`
	Pushed       bool   `json:"pushed"`
	At           int64  `json:"at"`
}

// adminListPersonas lists persona summaries (admin read).
func (s *Server) adminListPersonas(w http.ResponseWriter, r *http.Request) {
	writeJSON(w, http.StatusOK, s.collectPersonas())
}

// adminListSessions lists channel sessions (admin read).
func (s *Server) adminListSessions(w http.ResponseWriter, r *http.Request) {
	writeJSON(w, http.StatusOK, s.collectSessions(r.Context()))
}

// adminListMemories lists memory entries (admin read).
func (s *Server) adminListMemories(w http.ResponseWriter, r *http.Request) {
	writeJSON(w, http.StatusOK, s.collectMemories(r.Context()))
}

// adminListPlugins lists every registered capability (admin read).
func (s *Server) adminListPlugins(w http.ResponseWriter, r *http.Request) {
	out := make([]PluginSummary, 0)
	if s.caps != nil {
		for _, cap := range s.caps.List("") {
			out = append(out, PluginSummary{
				Name:            cap.Name,
				Kind:            string(cap.Kind),
				Description:     cap.Description,
				AllowInGroup:    cap.Policy.AllowInGroup,
				AllowInStranger: cap.Policy.AllowInStranger,
			})
		}
	}
	writeJSON(w, http.StatusOK, out)
}

// adminListChannels lists the registered channel adapters (admin read).
func (s *Server) adminListChannels(w http.ResponseWriter, r *http.Request) {
	out := make([]ChannelSummary, 0)
	if s.caps != nil {
		for _, cap := range s.caps.List(capreg.KindChannel) {
			ch, ok := cap.Value.(sdk.Channel)
			if !ok {
				continue
			}
			out = append(out, ChannelSummary{Name: ch.Name(), Connected: ch.IsConnected()})
		}
	}
	writeJSON(w, http.StatusOK, out)
}

// adminListIoT lists IoT devices (admin read).
func (s *Server) adminListIoT(w http.ResponseWriter, r *http.Request) {
	out := make([]iotDeviceSummary, 0)
	if s.iot != nil {
		devices, err := s.iot.List(r.Context())
		if err != nil {
			s.log.Error("list iot", "err", err)
			writeError(w, apperr.Wrap(apperr.ErrInternal, "iot_failed", "failed to list devices"))
			return
		}
		for _, d := range devices {
			out = append(out, iotDeviceSummary{ID: d.ID, Name: d.Name, Type: d.Type, State: d.State, Online: d.Online})
		}
	}
	writeJSON(w, http.StatusOK, out)
}

// adminGetLlm returns the LLM provider/model configuration read from the live
// config. API keys are never returned (the wire shape carries no key field), so
// the handler leaks nothing sensitive.
func (s *Server) adminGetLlm(w http.ResponseWriter, r *http.Request) {
	cfg := s.cfg.LLM
	providers := []AdminLlmProvider{
		{
			ID:         "openai",
			Name:       "OpenAI",
			BaseURL:    cfg.BaseURL,
			Model:      cfg.Model,
			Multimodal: cfg.VisionModel != "",
			Enabled:    cfg.Provider != "anthropic",
			Fallback:   cfg.Fallback,
		},
		{
			ID:         "anthropic",
			Name:       "Anthropic",
			BaseURL:    cfg.AnthropicBaseURL,
			Model:      cfg.AnthropicModel,
			Multimodal: false,
			Enabled:    cfg.Provider == "anthropic",
			Fallback:   cfg.AnthropicFallback,
		},
	}
	// Fold in providers added at runtime via the admin "add provider" write.
	// They are process-lifetime and not bound to the model router, so the panel
	// reflects them but the response marks nothing else.
	s.llmMu.RLock()
	providers = append(providers, s.llmExtra...)
	s.llmMu.RUnlock()
	writeJSON(w, http.StatusOK, AdminLlmConfig{Providers: providers})
}

// adminListAutomations lists automations and reminders (admin read).
func (s *Server) adminListAutomations(w http.ResponseWriter, r *http.Request) {
	out := make([]AdminAutomationRecord, 0)
	if s.automations != nil {
		for _, a := range s.automations.List() {
			rec := AdminAutomationRecord{
				ID:      a.ID,
				Name:    a.Name,
				Kind:    a.Kind,
				Cron:    a.Cron,
				Enabled: a.Enabled,
			}
			if !a.LastRun.IsZero() {
				rec.LastRun = a.LastRun.Format(time.RFC3339)
			}
			if !a.NextRun.IsZero() {
				rec.NextRun = a.NextRun.Format(time.RFC3339)
			}
			out = append(out, rec)
		}
	}
	writeJSON(w, http.StatusOK, out)
}

// adminListUsers lists accounts and API keys (admin read). Without a wired
// UserStore it reports the single configured admin account rather than
// fabricating a column of virtual users.
func (s *Server) adminListUsers(w http.ResponseWriter, r *http.Request) {
	out := []AdminUserRecord{{
		ID:       "admin",
		Username: s.cfg.Auth.AdminUser,
		Role:     string(auth.RoleOwner),
	}}
	if s.users != nil {
		for _, u := range s.users.List() {
			rec := AdminUserRecord{ID: u.ID, Username: u.Username, Role: string(u.Role)}
			if u.CreatedAt != nil {
				rec.CreatedAt = u.CreatedAt.Format(time.RFC3339)
			}
			out = append(out, rec)
		}
	}
	writeJSON(w, http.StatusOK, out)
}

// adminListBackthink lists the most recent background-think records (admin read).
func (s *Server) adminListBackthink(w http.ResponseWriter, r *http.Request) {
	out := make([]AdminBackthinkItem, 0)
	if s.backthink == nil {
		writeJSON(w, http.StatusOK, out)
		return
	}
	records, err := s.backthink.List(r.Context(), backthinkListLimit)
	if err != nil {
		s.log.Error("list backthink", "err", err)
		writeError(w, apperr.Wrap(apperr.ErrInternal, "backthink_failed", "failed to list backthink records"))
		return
	}
	for _, rec := range records {
		out = append(out, AdminBackthinkItem{
			ID:           strconv.FormatInt(rec.ID, 10),
			Trigger:      rec.Trigger,
			Conclusion:   rec.Conclusion,
			ShouldNotify: rec.ShouldPush,
			Pushed:       rec.PushResult.Pushed,
			At:           rec.At.UnixMilli(),
		})
	}
	writeJSON(w, http.StatusOK, out)
}

// AdminRagDoc is the wire shape of one knowledge-base document (project-index
// entry) in the admin RAG list.
type AdminRagDoc struct {
	ID       string `json:"id"`
	Name     string `json:"name"`
	Desc     string `json:"desc,omitempty"`
	Chunks   int    `json:"chunks"`
	Embedded bool   `json:"embedded"`
}

// AdminRagHit is the wire shape of one RAG retrieval hit.
type AdminRagHit struct {
	DocID    string  `json:"docId"`
	DocName  string  `json:"docName"`
	Chapter  string  `json:"chapter,omitempty"`
	Text     string  `json:"text"`
	Score    float64 `json:"score"`
	Semantic bool    `json:"semantic"`
}

// AdminRagResponse is the wire shape of GET /api/v1/admin/rag. Hits is present
// only when a query parameter was supplied, so callers distinguish "no search
// requested" from "searched and found nothing".
type AdminRagResponse struct {
	Documents []AdminRagDoc `json:"documents"`
	Hits      []AdminRagHit `json:"hits,omitempty"`
}

// ragQueryRequest is the POST /api/v1/admin/rag/query body.
type ragQueryRequest struct {
	Query string `json:"query"`
}

// ragDeleteRequest is the POST /api/v1/admin/rag/delete body.
type ragDeleteRequest struct {
	ID string `json:"id"`
}

// adminListRag lists the knowledge-base documents and, when ?query= is present,
// returns the matching hits too. Without a wired RagStore it degrades to an empty
// list (backward compatible — never a 500).
func (s *Server) adminListRag(w http.ResponseWriter, r *http.Request) {
	out := AdminRagResponse{Documents: make([]AdminRagDoc, 0)}
	if s.rag == nil {
		writeJSON(w, http.StatusOK, out)
		return
	}
	docs, err := s.rag.ListDocuments(r.Context())
	if err != nil {
		s.log.Error("list rag", "err", err)
		writeError(w, apperr.Wrap(apperr.ErrInternal, "rag_failed", "failed to list knowledge documents"))
		return
	}
	out.Documents = ragDocsFrom(docs)
	if query := strings.TrimSpace(r.URL.Query().Get("query")); query != "" {
		hits, herr := s.rag.Search(r.Context(), query)
		if herr != nil {
			s.log.Error("search rag", "err", herr)
			writeError(w, apperr.Wrap(apperr.ErrInternal, "rag_search_failed", "failed to search knowledge base"))
			return
		}
		out.Hits = ragHitsFrom(hits)
	}
	writeJSON(w, http.StatusOK, out)
}

// adminSearchRag runs a knowledge-base query and returns the matching hits.
func (s *Server) adminSearchRag(w http.ResponseWriter, r *http.Request) {
	if s.rag == nil {
		s.auditClaims(r, "rag.query", "error")
		writeError(w, &apperr.AppError{Code: "not_implemented", Message: "知识库 RAG 服务未配置（未注入 RagStore）", HTTPCode: http.StatusNotImplemented})
		return
	}
	var req ragQueryRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeError(w, apperr.Wrap(apperr.ErrBadRequest, "bad_request", "invalid request body"))
		return
	}
	if strings.TrimSpace(req.Query) == "" {
		writeError(w, apperr.Wrap(apperr.ErrBadRequest, "bad_request", "query is required"))
		return
	}
	hits, err := s.rag.Search(r.Context(), req.Query)
	if err != nil {
		s.log.Error("search rag", "err", err)
		writeError(w, apperr.Wrap(apperr.ErrInternal, "rag_search_failed", "failed to search knowledge base"))
		return
	}
	s.auditClaims(r, "rag.query", "ok")
	writeJSON(w, http.StatusOK, map[string]any{"query": req.Query, "hits": ragHitsFrom(hits)})
}

// adminDeleteRag answers the document delete honestly: write operations
// (upload/chunk/embed/delete) are milestone M10, so it returns a clear 501 rather
// than a fabricated success. The route is audited as an admin write.
func (s *Server) adminDeleteRag(w http.ResponseWriter, r *http.Request) {
	if s.rag == nil {
		s.auditClaims(r, "rag.delete", "error")
		writeError(w, &apperr.AppError{Code: "not_implemented", Message: "知识库 RAG 服务未配置（未注入 RagStore）", HTTPCode: http.StatusNotImplemented})
		return
	}
	var req ragDeleteRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeError(w, apperr.Wrap(apperr.ErrBadRequest, "bad_request", "invalid request body"))
		return
	}
	if strings.TrimSpace(req.ID) == "" {
		writeError(w, apperr.Wrap(apperr.ErrBadRequest, "bad_request", "id is required"))
		return
	}
	if err := s.rag.DeleteDocument(r.Context(), req.ID); err != nil {
		s.auditClaims(r, "rag.delete", "error")
		writeError(w, &apperr.AppError{Code: "not_implemented", Message: "知识库写操作（上传/分块/嵌入/删除）由 M10 后端提供", HTTPCode: http.StatusNotImplemented})
		return
	}
	s.auditClaims(r, "rag.delete", "ok")
	writeJSON(w, http.StatusOK, map[string]any{"id": req.ID})
}

// ragDocsFrom maps knowledge docs to their admin wire shape.
func ragDocsFrom(docs []knowledge.Doc) []AdminRagDoc {
	out := make([]AdminRagDoc, 0, len(docs))
	for _, d := range docs {
		out = append(out, AdminRagDoc{ID: d.ID, Name: d.Name, Desc: d.Desc, Chunks: d.Chunks, Embedded: d.Embedded})
	}
	return out
}

// ragHitsFrom maps knowledge hits to their admin wire shape.
func ragHitsFrom(hits []knowledge.Hit) []AdminRagHit {
	out := make([]AdminRagHit, 0, len(hits))
	for _, h := range hits {
		out = append(out, AdminRagHit{
			DocID:    h.DocID,
			DocName:  h.DocName,
			Chapter:  h.Chapter,
			Text:     h.Text,
			Score:    h.Score,
			Semantic: h.Semantic,
		})
	}
	return out
}

// adminSetPolicy upserts the reachability markers for a capability. It is the
// audited admin write example (owner-only, enforced by the route registration).
func (s *Server) adminSetPolicy(w http.ResponseWriter, r *http.Request) {
	var req policyRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeError(w, apperr.Wrap(apperr.ErrBadRequest, "bad_request", "invalid request body"))
		return
	}
	if req.Name == "" {
		writeError(w, apperr.Wrap(apperr.ErrBadRequest, "bad_request", "name is required"))
		return
	}
	if s.caps == nil {
		s.auditClaims(r, "policy.set", "error")
		writeError(w, apperr.Wrap(apperr.ErrInternal, "policy_unavailable", "capability service is not configured"))
		return
	}
	err := s.caps.SetPolicy(req.Name, capreg.ToolPolicy{AllowInGroup: req.AllowInGroup, AllowInStranger: req.AllowInStranger})
	if err != nil {
		s.auditClaims(r, "policy.set", "error")
		if errors.Is(err, capreg.ErrNotFound) {
			writeError(w, apperr.Wrap(apperr.ErrNotFound, "not_found", "capability %q not found", req.Name))
			return
		}
		writeError(w, apperr.Wrap(apperr.ErrInternal, "policy_failed", "failed to set policy"))
		return
	}
	s.auditClaims(r, "policy.set", "ok")
	writeJSON(w, http.StatusOK, map[string]any{"name": req.Name, "allowInGroup": req.AllowInGroup, "allowInStranger": req.AllowInStranger})
}

// collectSessions returns a non-nil session slice from the configured store.
func (s *Server) collectSessions(ctx context.Context) []SessionSummary {
	out := make([]SessionSummary, 0)
	if s.sessions == nil {
		return out
	}
	list, err := s.sessions.List(ctx)
	if err != nil {
		s.log.Error("list sessions", "err", err)
		return out
	}
	for _, sess := range list {
		out = append(out, summaryOfSession(sess))
	}
	return out
}

// collectMemories returns a non-nil memory slice from the configured store.
func (s *Server) collectMemories(ctx context.Context) []MemorySummary {
	out := make([]MemorySummary, 0)
	if s.memories == nil {
		return out
	}
	list, err := s.memories.List(ctx)
	if err != nil {
		s.log.Error("list memories", "err", err)
		return out
	}
	for _, it := range list {
		out = append(out, MemorySummary{ID: it.ID, Scope: string(it.Scope), Text: it.Content})
	}
	return out
}

// iotDeviceSummary is the wire shape of an IoT device.
type iotDeviceSummary struct {
	ID     string         `json:"id"`
	Name   string         `json:"name"`
	Type   string         `json:"type"`
	State  map[string]any `json:"state"`
	Online bool           `json:"online"`
}