// backend\operation_assignees.go

package main

import (
	"context"
	"net/http"
	"strings"
)

type operationAssigneeUser struct {
	ID          string `json:"id"`
	Username    string `json:"username"`
	DisplayName string `json:"displayName"`
	Email       string `json:"email"`
	Avatar      string `json:"avatar"`
	Unit        string `json:"unit"`
	Group       string `json:"group"`
}

func (s *Server) handleListOperationAssignees(w http.ResponseWriter, r *http.Request) {
	unit := strings.TrimSpace(r.URL.Query().Get("unit"))
	if unit == "" {
		unit = "TEG"
	}

	leaders, err := s.listOperationAssigneeUsers(r.Context(), unit, "operation-leader")
	if err != nil {
		writeError(w, http.StatusInternalServerError, "Einsatzleiter konnten nicht geladen werden")
		return
	}

	officers, err := s.listOperationAssigneeUsers(r.Context(), unit, "operation-officer")
	if err != nil {
		writeError(w, http.StatusInternalServerError, "Einsatzbeamte konnten nicht geladen werden")
		return
	}

	writeJSON(w, http.StatusOK, map[string]any{
		"leaders":  leaders,
		"officers": officers,
	})
}

func (s *Server) listOperationAssigneeUsers(
	ctx context.Context,
	unit string,
	group string,
) ([]operationAssigneeUser, error) {
	rows, err := s.db.Query(
		ctx,
		`
		SELECT
			id::TEXT,
			COALESCE(username, ''),
			COALESCE(display_name, ''),
			email,
			COALESCE(avatar, ''),
			COALESCE(unit, ''),
			COALESCE(user_group, '')
		FROM users
		WHERE upper(COALESCE(unit, '')) = upper($1)
		  AND COALESCE(user_group, '') = $2
		ORDER BY
			lower(COALESCE(NULLIF(display_name, ''), NULLIF(username, ''), email)) ASC,
			lower(email) ASC
		`,
		unit,
		group,
	)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	users := []operationAssigneeUser{}

	for rows.Next() {
		var user operationAssigneeUser

		if err := rows.Scan(
			&user.ID,
			&user.Username,
			&user.DisplayName,
			&user.Email,
			&user.Avatar,
			&user.Unit,
			&user.Group,
		); err != nil {
			return nil, err
		}

		users = append(users, user)
	}

	if err := rows.Err(); err != nil {
		return nil, err
	}

	return users, nil
}