package handlers

import (
	"encoding/json"
	"errors"
	"net/http"
	"strconv"

	"github.com/go-chi/chi/v5"
	"github.com/noderunners/nip05api/internal/audit"
	"github.com/noderunners/nip05api/internal/dm"
	"github.com/noderunners/nip05api/internal/nostr"
	"github.com/noderunners/nip05api/internal/user"
	"github.com/noderunners/nip05api/internal/webhook"
)

type AdminUsers struct {
	Users    *user.Service
	DMs      *dm.Service
	Hooks    *webhook.Service
	Audit    *audit.Logger
	Domain   string
	Frontend string
}

type adminAddReq struct {
	Pubkey           string `json:"pubkey"`
	Username         string `json:"username"`
	SubscriptionType string `json:"subscription_type"`
	Years            int    `json:"years"`
}

func (h *AdminUsers) Add(w http.ResponseWriter, r *http.Request) {
	var body adminAddReq
	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
		WriteError(w, http.StatusBadRequest, "ValidationError", "invalid JSON")
		return
	}
	hexpk, err := nostr.NormalizePubkey(body.Pubkey)
	if err != nil {
		WriteError(w, http.StatusBadRequest, "ValidationError", "Invalid pubkey format")
		return
	}
	sub := user.SubscriptionType(body.SubscriptionType)
	if !sub.Valid() {
		WriteError(w, http.StatusBadRequest, "ValidationError", "invalid subscription_type")
		return
	}
	years := body.Years
	if years <= 0 {
		years = 1
	}

	if existing, err := h.Users.Repo().GetByPubkey(r.Context(), hexpk); err == nil && existing != nil {
		WriteError(w, http.StatusConflict, "Conflict", "user already exists")
		return
	}
	if existing, err := h.Users.Repo().GetByUsername(r.Context(), user.NormalizeUsername(body.Username)); err == nil && existing != nil {
		WriteError(w, http.StatusConflict, "Conflict", "username taken")
		return
	}

	u, err := h.Users.CreateOrActivate(r.Context(), hexpk, body.Username, sub, years, true)
	if err != nil {
		if errors.Is(err, user.ErrInvalidUsername) {
			WriteError(w, http.StatusBadRequest, "ValidationError", "invalid username")
			return
		}
		WriteError(w, http.StatusInternalServerError, "InternalError", err.Error())
		return
	}

	vars := dmVars(u, h.Domain, h.Frontend)
	_ = h.DMs.Send(r.Context(), dm.EventWelcome, u.Pubkey, vars)
	_ = h.Hooks.Enqueue(r.Context(), webhook.EventUserAdded, hookData(u, h.Domain))
	h.Audit.Log(r.Context(), audit.ActionUserAdded, audit.ActorAdmin, u.Pubkey, map[string]any{
		"username":          u.Username,
		"subscription_type": string(u.SubscriptionType),
		"years":             years,
	})

	WriteJSON(w, http.StatusCreated, userResponse(u))
}

func (h *AdminUsers) List(w http.ResponseWriter, r *http.Request) {
	q := r.URL.Query()
	activeOnly := q.Get("active") == "true"
	limit, _ := strconv.Atoi(q.Get("limit"))
	if limit <= 0 {
		limit = 100
	}
	users, err := h.Users.Repo().List(r.Context(), user.ListFilter{
		ActiveOnly: activeOnly,
		Search:     q.Get("q"),
		Limit:      limit,
	})
	if err != nil {
		WriteError(w, http.StatusInternalServerError, "InternalError", err.Error())
		return
	}
	out := make([]map[string]any, 0, len(users))
	for _, u := range users {
		out = append(out, userResponse(u))
	}
	WriteJSON(w, http.StatusOK, out)
}

func (h *AdminUsers) Update(w http.ResponseWriter, r *http.Request) {
	hexpk, err := nostr.NormalizePubkey(chi.URLParam(r, "pubkey"))
	if err != nil {
		WriteError(w, http.StatusBadRequest, "ValidationError", "Invalid pubkey format")
		return
	}
	var body struct {
		Username string `json:"username"`
	}
	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
		WriteError(w, http.StatusBadRequest, "ValidationError", "invalid JSON")
		return
	}
	u, err := h.Users.SetUsername(r.Context(), hexpk, body.Username)
	if err != nil {
		switch {
		case errors.Is(err, user.ErrUserNotFound):
			WriteError(w, http.StatusNotFound, "NotFound", "user not found")
		case errors.Is(err, user.ErrInvalidUsername):
			WriteError(w, http.StatusBadRequest, "ValidationError", "invalid username")
		case errors.Is(err, user.ErrUsernameTaken):
			WriteError(w, http.StatusConflict, "Conflict", "username taken")
		default:
			WriteError(w, http.StatusInternalServerError, "InternalError", err.Error())
		}
		return
	}
	h.Audit.Log(r.Context(), audit.ActionUserUsernameChanged, audit.ActorAdmin, u.Pubkey, map[string]any{
		"username": u.Username,
	})
	WriteJSON(w, http.StatusOK, userResponse(u))
}

func (h *AdminUsers) Delete(w http.ResponseWriter, r *http.Request) {
	hexpk, err := nostr.NormalizePubkey(chi.URLParam(r, "pubkey"))
	if err != nil {
		WriteError(w, http.StatusBadRequest, "ValidationError", "Invalid pubkey format")
		return
	}
	u, err := h.Users.Repo().GetByPubkey(r.Context(), hexpk)
	if errors.Is(err, user.ErrUserNotFound) {
		WriteError(w, http.StatusNotFound, "NotFound", "user not found")
		return
	}
	if err != nil {
		WriteError(w, http.StatusInternalServerError, "InternalError", err.Error())
		return
	}
	if err := h.Users.Delete(r.Context(), hexpk); err != nil {
		WriteError(w, http.StatusInternalServerError, "InternalError", err.Error())
		return
	}
	_ = h.Hooks.Enqueue(r.Context(), webhook.EventUserRemoved, hookData(u, h.Domain))
	h.Audit.Log(r.Context(), audit.ActionUserDeleted, audit.ActorAdmin, u.Pubkey, map[string]any{
		"username": u.Username,
	})
	WriteJSON(w, http.StatusOK, map[string]bool{"deleted": true})
}