package server

import (
	"errors"
	"io"
	"net/http"
	"strings"

	"chat-agent-system/internal/workflowdef"
)

func (s *Server) handleAdminTemplates(w http.ResponseWriter, r *http.Request) {
	user, ok := s.requireWorkflowAdmin(w, r)
	if !ok {
		return
	}

	switch r.Method {
	case http.MethodGet:
		assets, err := s.wfDefSvc.ListTemplates(r.Context())
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		writeJSONResponse(w, http.StatusOK, map[string]any{"templates": assets})
	case http.MethodPost:
		if err := r.ParseMultipartForm(defaultUploadBodyLimit); err != nil {
			if isRequestBodyTooLarge(err) {
				http.Error(w, "upload too large", http.StatusRequestEntityTooLarge)
				return
			}
			http.Error(w, "invalid multipart", http.StatusBadRequest)
			return
		}
		assetKey := strings.TrimSpace(r.FormValue("asset_key"))
		name := strings.TrimSpace(r.FormValue("name"))
		if assetKey == "" {
			assetKey = strings.TrimSpace(r.FormValue("key"))
		}
		if name == "" {
			name = assetKey
		}
		file, header, err := r.FormFile("file")
		if err != nil || assetKey == "" {
			http.Error(w, "asset_key and file required", http.StatusBadRequest)
			return
		}
		defer file.Close()
		data, err := io.ReadAll(io.LimitReader(file, 32<<20))
		if err != nil {
			http.Error(w, "read file failed", http.StatusBadRequest)
			return
		}
		tv, err := s.wfDefSvc.UploadTemplate(r.Context(), assetKey, name, data, header.Filename, user.ID)
		if err != nil {
			status := http.StatusBadRequest
			switch {
			case errors.Is(err, workflowdef.ErrUploadRejected):
				status = http.StatusUnsupportedMediaType
			case errors.Is(err, workflowdef.ErrNotAvailable):
				status = http.StatusServiceUnavailable
			}
			http.Error(w, err.Error(), status)
			return
		}
		writeJSONResponse(w, http.StatusCreated, tv)
	default:
		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
	}
}

func (s *Server) handleAdminTemplateVersions(w http.ResponseWriter, r *http.Request) {
	if _, ok := s.requireWorkflowAdmin(w, r); !ok {
		return
	}
	if r.Method != http.MethodGet {
		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
		return
	}
	assetKey := strings.TrimSpace(r.PathValue("key"))
	if assetKey == "" {
		http.Error(w, "invalid asset key", http.StatusBadRequest)
		return
	}
	versions, err := s.wfDefSvc.ListTemplateVersions(r.Context(), assetKey)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	writeJSONResponse(w, http.StatusOK, map[string]any{"versions": versions})
}