package httpapi

import (
	"errors"
	"log"
	"net/http"
	"strconv"
	"strings"

	"git.118im.com/im_team/olons_server/internal/support"
)

type customerServiceSessionRequest struct {
	DeviceID   string `json:"device_id"`
	Platform   string `json:"platform"`
	AppVersion string `json:"app_version"`
}

func (a *API) customerServiceResource(w http.ResponseWriter, r *http.Request) {
	path := strings.Trim(strings.TrimPrefix(r.URL.Path, "/v1/customer-services/"), "/")
	parts := strings.Split(path, "/")
	if len(parts) != 2 || parts[1] != "session" {
		writeError(w, r, http.StatusNotFound, 30004, "RESOURCE_NOT_FOUND", "resource not found", nil)
		return
	}
	serviceID, err := strconv.ParseInt(parts[0], 10, 64)
	if err != nil || serviceID <= 0 {
		writeError(w, r, http.StatusNotFound, 30004, "RESOURCE_NOT_FOUND", "resource not found", nil)
		return
	}
	if r.Method != http.MethodPost {
		methodNotAllowed(w, r, http.MethodPost)
		return
	}
	principal, ok := a.authenticateMember(w, r)
	if !ok {
		return
	}
	if a.support == nil {
		writeSupportError(w, r, support.ErrIMUnavailable)
		return
	}
	var body customerServiceSessionRequest
	if !decodeBody(w, r, &body) {
		return
	}
	deviceID := strings.TrimSpace(body.DeviceID)
	if deviceID == "" {
		deviceID = principal.DeviceID
	}
	result, err := a.support.OpenSession(r.Context(), principal.TenantID, principal.MemberID, serviceID,
		support.SessionRequest{DeviceID: deviceID, Platform: body.Platform})
	if err != nil {
		writeSupportError(w, r, err)
		return
	}
	writeSuccess(w, r, result)
}

func writeSupportError(w http.ResponseWriter, r *http.Request, err error) {
	log.Printf("customer service session failed request_id=%s err=%v", r.Header.Get("X-Request-ID"), err)
	switch {
	case errors.Is(err, support.ErrServiceNotFound):
		writeError(w, r, http.StatusNotFound, 41001, "CUSTOMER_SERVICE_NOT_FOUND", "customer service not found", nil)
	case errors.Is(err, support.ErrServiceNotBound):
		writeError(w, r, http.StatusConflict, 41002, "CUSTOMER_SERVICE_NOT_BOUND", "customer service account is not configured", nil)
	case errors.Is(err, support.ErrRelationPending):
		writeError(w, r, http.StatusConflict, 41003, "IM_RELATION_PENDING", "customer service relationship is pending", nil)
	case errors.Is(err, support.ErrRelationDenied):
		writeError(w, r, http.StatusForbidden, 41004, "IM_RELATION_NOT_ALLOWED", "customer service relationship is not allowed", nil)
	case errors.Is(err, support.ErrIMUnavailable):
		writeError(w, r, http.StatusServiceUnavailable, 41005, "IM_SERVICE_UNAVAILABLE", "IM service unavailable", nil)
	default:
		writeError(w, r, http.StatusBadGateway, 41006, "IM_SERVICE_UNAVAILABLE", "IM service unavailable", nil)
	}
}