package httpapi

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

	"github.com/descrybe/descrybe-v2/apps/api/internal/auth"
	"github.com/descrybe/descrybe-v2/apps/api/internal/support"
	"github.com/go-chi/chi/v5"
	"github.com/google/uuid"
)

// handleAdminListStaff returns platform staff users (admin|developer only).
// GET /api/admin/staff
func (s *Server) handleAdminListStaff(w http.ResponseWriter, r *http.Request) {
	if s.Auth == nil {
		Error(w, http.StatusServiceUnavailable, "auth unavailable")
		return
	}
	limit, offset := ParseLimitOffset(r)
	users, err := s.Auth.ListStaffUsers(r.Context(), limit, offset)
	if err != nil {
		Error(w, http.StatusInternalServerError, "list failed")
		return
	}
	JSON(w, http.StatusOK, map[string]any{
		"staff":  users,
		"limit":  limit,
		"offset": offset,
	})
}

// handleAdminSetStaffRole assigns or clears a platform staff role (admin|developer only).
// PATCH /api/admin/users/{id}/staff-role
// Body: {"staff_role":"admin"|"developer"|"support_staff"|null}
func (s *Server) handleAdminSetStaffRole(w http.ResponseWriter, r *http.Request) {
	if s.Auth == nil {
		Error(w, http.StatusServiceUnavailable, "auth unavailable")
		return
	}
	actorID, ok := UserIDFromContext(r.Context())
	if !ok {
		Error(w, http.StatusUnauthorized, "unauthorized")
		return
	}
	targetID, err := uuid.Parse(chi.URLParam(r, "id"))
	if err != nil {
		Error(w, http.StatusBadRequest, "invalid id")
		return
	}
	if targetID == actorID {
		Error(w, http.StatusForbidden, "cannot change own staff role")
		return
	}

	var body struct {
		StaffRole *string `json:"staff_role"`
	}
	dec := json.NewDecoder(r.Body)
	dec.DisallowUnknownFields()
	if err := dec.Decode(&body); err != nil {
		Error(w, http.StatusBadRequest, "invalid json")
		return
	}
	role := ""
	if body.StaffRole != nil {
		role = strings.TrimSpace(*body.StaffRole)
	}
	user, err := s.Auth.SetStaffRole(r.Context(), targetID, role)
	if err != nil {
		if errors.Is(err, auth.ErrInvalidStaffRole) {
			Error(w, http.StatusBadRequest, "invalid staff_role")
			return
		}
		if errors.Is(err, auth.ErrStaffUserNotFound) {
			Error(w, http.StatusNotFound, "user not found")
			return
		}
		Error(w, http.StatusInternalServerError, "update failed")
		return
	}
	JSON(w, http.StatusOK, map[string]any{
		"user":               user,
		"staff_capabilities": auth.StaffCapabilities(user.ResolvedRole),
	})
}

// handleAdminSetSupportAgent grants or revokes support_staff only (full-admin exclusive).
// PUT /api/admin/support/agents/{id}
// Body: {"enabled": true|false} or {"is_support_agent": true|false}
func (s *Server) handleAdminSetSupportAgent(w http.ResponseWriter, r *http.Request) {
	if s.Support == nil {
		Error(w, http.StatusServiceUnavailable, "support unavailable")
		return
	}
	actorID, ok := UserIDFromContext(r.Context())
	if !ok {
		Error(w, http.StatusUnauthorized, "unauthorized")
		return
	}
	targetID, err := uuid.Parse(chi.URLParam(r, "id"))
	if err != nil {
		Error(w, http.StatusBadRequest, "invalid id")
		return
	}
	if targetID == actorID {
		Error(w, http.StatusForbidden, "cannot change own support agent flag")
		return
	}
	var body struct {
		Enabled        *bool `json:"enabled"`
		IsSupportAgent *bool `json:"is_support_agent"`
	}
	if err := DecodeJSON(r, &body); err != nil {
		Error(w, http.StatusBadRequest, "invalid json")
		return
	}
	enable := false
	switch {
	case body.Enabled != nil:
		enable = *body.Enabled
	case body.IsSupportAgent != nil:
		enable = *body.IsSupportAgent
	default:
		Error(w, http.StatusBadRequest, "enabled required")
		return
	}
	agent, err := s.Support.SetSupportAgent(r.Context(), targetID, enable)
	if errors.Is(err, support.ErrNotFound) {
		Error(w, http.StatusNotFound, "user not found")
		return
	}
	if err != nil {
		LogAndError(w, http.StatusInternalServerError, "update failed", err)
		return
	}
	JSON(w, http.StatusOK, map[string]any{"agent": agent})
}