Reassign a Customer and Ship-To Salesrep

using System.Net.Http.Headers;
using System.Text;
using System.Text.Json;

// ---- EDIT THESE -----------------------------------------------------------
const string BaseUrl = "https://play.p21server.com";   // your P21 server
const string Username = "api_user";
const string Password = "api_pass";
const string CompanyId = "ACME";
const string CustomerId = "100198";
const string ShipToId = "100198";
const string OldSalesrepId = "100";
const string NewSalesrepId = "200";
// ---------------------------------------------------------------------------

var handler = new HttpClientHandler
{
    ServerCertificateCustomValidationCallback =
        HttpClientHandler.DangerousAcceptAnyServerCertificateValidator,
};
using var client = new HttpClient(handler) { Timeout = TimeSpan.FromMinutes(2) };
client.DefaultRequestHeaders.Accept.Add(
    new MediaTypeWithQualityHeaderValue("application/json"));
var token = await GetTokenAsync(client);
var uiServer = await GetUiServerAsync(client, token);
client.DefaultRequestHeaders.Authorization =
    new AuthenticationHeaderValue("Bearer", token);

var customer = new
{
    Name = "Customer",
    UseCodeValues = false,
    Transactions = new[]
    {
        new
        {
            Status = "New",
            DataElements = new object[]
            {
                new
                {
                    Name = "TABPAGE_1.tp_1_dw_1",
                    Type = "Form",
                    Keys = Array.Empty<string>(),
                    Rows = new[]
                    {
                        new
                        {
                            Edits = new[]
                            {
                                new { Name = "company_id", Value = CompanyId },
                                new { Name = "customer_id", Value = CustomerId },
                                new { Name = "salesrep_id", Value = NewSalesrepId },
                            },
                            RelativeDateEdits = Array.Empty<object>(),
                        },
                    },
                },
                new
                {
                    Name = "CUSTOMERSALESREP.customersalesrep",
                    Type = "List",
                    Keys = new[] { "salesrep_id" },
                    // Promote first, then delete: the outgoing rep cannot be
                    // deleted while they are still the primary.
                    Rows = new object[]
                    {
                        new
                        {
                            Edits = new[]
                            {
                                new { Name = "salesrep_id", Value = NewSalesrepId },
                                new { Name = "primary_salesrep_flag", Value = "ON" },
                                new { Name = "commission_percentage", Value = "100" },
                            },
                            RelativeDateEdits = Array.Empty<object>(),
                        },
                        new
                        {
                            Edits = new[]
                            {
                                new { Name = "salesrep_id", Value = OldSalesrepId },
                                new { Name = "row_status_flag", Value = "Delete" },
                            },
                            RelativeDateEdits = Array.Empty<object>(),
                        },
                    },
                },
            },
        },
    },
};

var shipto = new
{
    Name = "ShipTo",
    UseCodeValues = false,
    Transactions = new[]
    {
        new
        {
            Status = "New",
            DataElements = new object[]
            {
                new
                {
                    Name = "TABPAGE_1.shiptomain",
                    Type = "Form",
                    Keys = Array.Empty<string>(),
                    Rows = new[]
                    {
                        new
                        {
                            Edits = new[]
                            {
                                new { Name = "company_id", Value = CompanyId },
                                new { Name = "address_id", Value = ShipToId },
                            },
                            RelativeDateEdits = Array.Empty<object>(),
                        },
                    },
                },
                new
                {
                    Name = "TABPAGE_SALESREP.tabpage_salesrep",
                    Type = "List",
                    Keys = new[] { "salesrep_id" },
                    Rows = new[]
                    {
                        new
                        {
                            Edits = new[]
                            {
                                new { Name = "salesrep_id", Value = NewSalesrepId },
                                new { Name = "primary_salesrep", Value = "ON" },
                            },
                            RelativeDateEdits = Array.Empty<object>(),
                        },
                        new
                        {
                            Edits = new[]
                            {
                                new { Name = "salesrep_id", Value = OldSalesrepId },
                                new { Name = "delete_flag", Value = "ON" },
                            },
                            RelativeDateEdits = Array.Empty<object>(),
                        },
                    },
                },
            },
        },
    },
};

await PostTransactionAsync(client, uiServer, customer);
await PostTransactionAsync(client, uiServer, shipto);

foreach (var row in await ODataAsync(
    client, "customer_salesrep", $"customer_id eq {CustomerId}"))
{
    // row_status_flag 704 = Active, 700 = Delete — the old rep's row survives at 700.
    Console.WriteLine(
        $"customer: salesrep_id={row.GetProperty("salesrep_id")} " +
        $"primary_salesrep_flag={row.GetProperty("primary_salesrep_flag")} " +
        $"row_status_flag={row.GetProperty("row_status_flag")}");
}

foreach (var row in await ODataAsync(
    client, "ship_to_salesrep", $"ship_to_id eq {ShipToId}"))
{
    Console.WriteLine(
        $"ship-to: salesrep_id={row.GetProperty("salesrep_id")} " +
        $"primary_salesrep={row.GetProperty("primary_salesrep")}");
}

static async Task PostTransactionAsync(HttpClient c, string ui, object p)
{
    using var r = await c.PostAsync(
        $"{ui}/api/v2/transaction",
        new StringContent(JsonSerializer.Serialize(p), Encoding.UTF8, "application/json"));
    r.EnsureSuccessStatusCode();
    using var d = JsonDocument.Parse(await r.Content.ReadAsStringAsync());
    var s = d.RootElement.GetProperty("Summary");
    var st = d.RootElement.GetProperty("Results")
        .GetProperty("Transactions")[0]
        .GetProperty("Status")
        .GetString();
    if (s.GetProperty("Failed").GetInt32() > 0 ||
        s.GetProperty("Succeeded").GetInt32() == 0 ||
        st != "Passed")
    {
        Console.Error.WriteLine(d.RootElement.GetProperty("Messages"));
        throw new InvalidOperationException($"Transaction failed; status={st}");
    }
}

static async Task<List<JsonElement>> ODataAsync(
    HttpClient c, string table, string filter)
{
    using var r = await c.GetAsync(
        $"{BaseUrl}/odataservice/odata/table/{table}?$filter=" +
        Uri.EscapeDataString(filter));
    r.EnsureSuccessStatusCode();
    using var d = JsonDocument.Parse(await r.Content.ReadAsStringAsync());
    return d.RootElement.GetProperty("value")
        .EnumerateArray()
        .Select(x => x.Clone())
        .ToList();
}

// v2 token endpoint — credentials go in the body, never in headers.
static async Task<string> GetTokenAsync(HttpClient c)
{
    var p = JsonSerializer.Serialize(new { username = Username, password = Password });
    using var r = await c.PostAsync(
        $"{BaseUrl}/api/security/token/v2",
        new StringContent(p, Encoding.UTF8, "application/json"));
    r.EnsureSuccessStatusCode();
    return ReadField(await r.Content.ReadAsStringAsync(), "AccessToken");
}

// Transaction and Interactive calls go to the UI server, not BaseUrl.
static async Task<string> GetUiServerAsync(HttpClient c, string token)
{
    using var q = new HttpRequestMessage(
        HttpMethod.Get, $"{BaseUrl}/api/ui/router/v1/?urlType=external");
    q.Headers.Authorization = new AuthenticationHeaderValue("Bearer", token);
    using var r = await c.SendAsync(q);
    r.EnsureSuccessStatusCode();
    return ReadField(await r.Content.ReadAsStringAsync(), "Url").TrimEnd('/');
}

// Some middleware answers these two endpoints in XML even when asked for JSON.
static string ReadField(string p, string f)
{
    try
    {
        var v = JsonDocument.Parse(p).RootElement.GetProperty(f).GetString();
        if (!string.IsNullOrEmpty(v))
        {
            return v;
        }
    }
    catch (Exception ex) when (
        ex is JsonException or KeyNotFoundException)
    {
    }

    var m = System.Text.RegularExpressions.Regex.Match(
        p, $"<{f}>([^<]+)</{f}>");
    if (!m.Success)
    {
        throw new InvalidOperationException(
            $"No {f} in response: {p[..Math.Min(200, p.Length)]}");
    }
    return m.Groups[1].Value;
}