public static IApplicationBuilder UseNpgsqlRest(this IApplicationBuilder builder, NpgsqlRestOptions options)

{

if (options.ConnectionString is null && options.ConnectionFromServiceProvider is false)

{

throw new ArgumentException("Connection string is null and ConnectionFromServiceProvider is false. Set the connection string or use ConnectionFromServiceProvider");

}

ILogger? logger = null;

if (options.Logger is not null)

{

logger = options.Logger;

}

else if (builder is WebApplication app)

{

logger = app.Logger;

}

var dict = BuildDictionary(builder, options, logger);

var serviceProvider = builder.ApplicationServices;

builder.Use(async (context, next) =>

{

if (!dict.TryGetValue(context.Request.Path, out (Routine routine, RoutineEndpoint endpoint)[]? tupleArray))

{

var path = context.Request.Path.ToString();

if (path.EndsWith('/'))

{

if (!dict.TryGetValue(path[..^1], out tupleArray))

{

await next(context);

return;

}

}

else

{

if (!dict.TryGetValue(string.Concat(path, '/'), out tupleArray))

{

await next(context);

return;

}

}

}

JsonObject? jsonObj = null;

string? body = null;

var len = tupleArray.Length;

bool overloaded = len > 1;

for (var index = len - 1; index >= 0; index--)

{

var (routine, endpoint) = tupleArray[index];

if (!string.Equals(context.Request.Method, endpoint.Method.ToString(), StringComparison.OrdinalIgnoreCase))

{

continue;

}

if (overloaded)

{

if (endpoint.RequestParamType == RequestParamType.QueryString)

{

var count = endpoint.BodyParameterName is null ? context.Request.Query.Count : context.Request.Query.Count + 1;

if (routine.ParamCount != count)

{

continue;

}

}

else

{

if (jsonObj is null)

{

await ParseJsonBody();

if (jsonObj is null && routine.ParamCount > 0)

{

continue;

}

}

if (routine.ParamCount != (jsonObj?.Count ?? 0))

{

continue;

}

}

}

NpgsqlParameter?[] parameters = new NpgsqlParameter[routine.ParamCount]; // in GC we trust

bool hasNulls = false;

int? headerParameterIndex = null;

if (routine.ParamCount > 0)

{

if (endpoint.RequestParamType == RequestParamType.QueryString)

{

int setCount = 0;

for (var i = 0; i < routine.ParamCount; i++)

{

string p = endpoint.ParamNames[i];

var descriptor = routine.ParamTypeDescriptor[i];

var parameter = new NpgsqlParameter

{

NpgsqlDbType = descriptor.ActualDbType

};

if (context.Request.Query.TryGetValue(p, out var qsValue))

{

if (ParameterParser.TryParseParameter(ref qsValue, ref descriptor, ref parameter))

{

if (options.ValidateParameters is not null || options.ValidateParametersAsync is not null)

{

if (options.ValidateParameters is not null)

{

options.ValidateParameters(new(

context,

routine,

parameter,

paramName: p,

typeDescriptor: descriptor,

requestParamType: endpoint.RequestParamType,

queryStringValues: qsValue,

jsonBodyNode: null));

}

if (options.ValidateParametersAsync is not null)

{

await options.ValidateParametersAsync(new(

context,

routine,

parameter,

paramName: p,

typeDescriptor: descriptor,

requestParamType: endpoint.RequestParamType,

queryStringValues: qsValue,

jsonBodyNode: null));

}

if (context.Response.HasStarted || context.Response.StatusCode != (int)HttpStatusCode.OK)

{

return;

}

}

parameters[i] = parameter;

setCount++;

}

else

{

// parameters don't match, continuing to another overload

if (options.LogParameterMismatchWarnings)

{

LogWarning(

ref logger,

ref options,

"Could not create a valid database parameter of type {0} from value: \"{1}\", skipping path {2} and continuing to another overload...",

routine.ParamTypeDescriptor[0].DbType,

qsValue.ToString(),

context.Request.Path);

}

}

}

else

{

// set param endpoint.BodyParameterName here

if (endpoint.BodyParameterName is not null)

{

if (string.Equals(p, endpoint.BodyParameterName, StringComparison.Ordinal) ||

string.Equals(routine.ParamNames[i], endpoint.BodyParameterName, StringComparison.Ordinal))

{

await ParseJsonBody();

if (body is null)

{

parameter.Value = DBNull.Value;

}

else

{

StringValues bodyStringValues = body;

if (!ParameterParser.TryParseParameter(ref bodyStringValues, ref descriptor, ref parameter))

{

// parameters don't match, continuing to another overload

if (options.LogParameterMismatchWarnings)

{

LogWarning(

ref logger,

ref options,

"Could not create a valid database parameter of type {0} from value: \"{1}\", skipping path {2} and continuing to another overload...",

routine.ParamTypeDescriptor[0].DbType,

qsValue.ToString(),

context.Request.Path);

}

}

}

}

}

if (options.ValidateParameters is not null || options.ValidateParametersAsync is not null)

{

if (options.ValidateParameters is not null)

{

options.ValidateParameters(new(

context,

routine,

parameter,

paramName: p,

typeDescriptor: descriptor,

requestParamType: endpoint.RequestParamType,

queryStringValues: qsValue,

jsonBodyNode: null));

}

if (options.ValidateParametersAsync is not null)

{

await options.ValidateParametersAsync(new(

context,

routine,

parameter,

paramName: p,

typeDescriptor: descriptor,

requestParamType: endpoint.RequestParamType,

queryStringValues: qsValue,

jsonBodyNode: null));

}

if (context.Response.HasStarted || context.Response.StatusCode != (int)HttpStatusCode.OK)

{

return;

}

}

if (parameter.Value is null)

{

if (endpoint.RequestHeadersMode == RequestHeadersMode.Parameter)

{

if (string.Equals(p, endpoint.RequestHeadersParameterName, StringComparison.Ordinal) ||

string.Equals(routine.ParamNames[i], endpoint.RequestHeadersParameterName, StringComparison.Ordinal))

{

parameters[i] = parameter;

headerParameterIndex = i;

}

}

}

if (parameter.Value is not null || headerParameterIndex is not null)

{

parameters[i] = parameter;

setCount++;

}

else if (descriptor.HasDefault)

{

setCount++;

}

}

if (hasNulls is false && parameter?.Value == DBNull.Value)

{

hasNulls = true;

}

}

if (setCount != routine.ParamCount)

{

continue;

}

}

else

{

if (jsonObj is null)

{

await ParseJsonBody();

if (jsonObj is null)

{

continue;

}

}

int setCount = 0;

for (var i = 0; i < endpoint.ParamNames.Length; i++)

{

string p = endpoint.ParamNames[i];

var descriptor = routine.ParamTypeDescriptor[i];

var parameter = new NpgsqlParameter

{

NpgsqlDbType = descriptor.ActualDbType

};

if (((IDictionary<string, JsonNode?>)jsonObj).TryGetValue(p, out var value))

{

if (ParameterParser.TryParseParameter(ref value, ref descriptor, ref parameter))

{

if (options.ValidateParameters is not null || options.ValidateParametersAsync is not null)

{

if (options.ValidateParameters is not null)

{

options.ValidateParameters(new ParameterValidationValues(

context,

routine,

parameter,

paramName: p,

typeDescriptor: descriptor,

requestParamType: endpoint.RequestParamType,

queryStringValues: null,

jsonBodyNode: value));

}

if (options.ValidateParametersAsync is not null)

{

await options.ValidateParametersAsync(new(

context,

routine,

parameter,

paramName: p,

typeDescriptor: descriptor,

requestParamType: endpoint.RequestParamType,

queryStringValues: null,

jsonBodyNode: value));

}

if (context.Response.HasStarted || context.Response.StatusCode != (int)HttpStatusCode.OK)

{

return;

}

}

parameters[i] = parameter;

setCount++;

}

else

{

// parameters don't match, continuing to another overload

if (options.LogParameterMismatchWarnings)

{

LogWarning(

ref logger,

ref options,

"Could not create a valid database parameter of type {0} from value: \"{1}\", skipping path {2} and continuing to another overload...",

routine.ParamTypeDescriptor[0].DbType,

value,

context.Request.Path);

}

}

}

else

{

if (options.ValidateParameters is not null || options.ValidateParametersAsync is not null)

{

if (options.ValidateParameters is not null)

{

options.ValidateParameters(new ParameterValidationValues(

context,

routine,

parameter,

paramName: p,

typeDescriptor: descriptor,

requestParamType: endpoint.RequestParamType,

queryStringValues: null,

jsonBodyNode: null));

}

if (options.ValidateParametersAsync is not null)

{

await options.ValidateParametersAsync(new ParameterValidationValues(

context,

routine,

parameter,

paramName: p,

typeDescriptor: descriptor,

requestParamType: endpoint.RequestParamType,

queryStringValues: null,

jsonBodyNode: null));

}

if (context.Response.HasStarted || context.Response.StatusCode != (int)HttpStatusCode.OK)

{

return;

}

}

if (parameter.Value is null)

{

if (endpoint.RequestHeadersMode == RequestHeadersMode.Parameter)

{

if (string.Equals(p, endpoint.RequestHeadersParameterName, StringComparison.Ordinal) ||

string.Equals(routine.ParamNames[i], endpoint.RequestHeadersParameterName, StringComparison.Ordinal))

{

parameters[i] = parameter;

headerParameterIndex = i;

}

}

}

if (parameter.Value is not null || headerParameterIndex is not null)

{

parameters[i] = parameter;

setCount++;

}

else if (descriptor.HasDefault)

{

setCount++;

}

}

if (hasNulls is false && parameter?.Value == DBNull.Value)

{

hasNulls = true;

}

}

if (setCount != routine.ParamCount)

{

continue;

}

}

}

if (endpoint.RequiresAuthorization && context.User?.Identity?.IsAuthenticated is false)

{

context.Response.StatusCode = (int)HttpStatusCode.Unauthorized;

await context.Response.CompleteAsync();

return;

}

if (hasNulls && routine.IsStrict)

{

context.Response.StatusCode = (int)HttpStatusCode.NoContent;

await context.Response.CompleteAsync();

return;

}

string? headers = null;

if (endpoint.RequestHeadersMode != RequestHeadersMode.Ignore)

{

headers = "{";

var i = 0;

foreach (var header in context.Request.Headers)

{

if (i++ > 0)

{

headers = string.Concat(headers, ",");

}

var key = header.Key;

var value = header.Value.ToString();

headers = string.Concat(

headers,

PgConverters.SerializeString(ref key),

":",

PgConverters.SerializeString(ref value));

}

headers = string.Concat(headers, "}");

if (endpoint.RequestHeadersMode == RequestHeadersMode.Parameter)

{

if (headerParameterIndex.HasValue)

{

parameters[headerParameterIndex.Value]!.Value = headers;

}

}

}

NpgsqlConnection? connection = null;

try

{

if (options.ConnectionFromServiceProvider)

{

using IServiceScope? scope = options.ConnectionFromServiceProvider ? serviceProvider.CreateScope() : null;

connection = scope?.ServiceProvider.GetRequiredService<NpgsqlConnection>();

}

else

{

connection = new(options.ConnectionString);

}

if (connection is null)

{

continue;

}

if (options.LogConnectionNoticeEvents && logger != null)

{

connection.Notice += (sender, args) =>

{

LogConnectionNotice(ref logger, ref options, ref args);

};

}

if (connection.State != ConnectionState.Open)

{

await connection.OpenAsync();

}

await using var command = connection.CreateCommand();

if (endpoint.RequestHeadersMode == RequestHeadersMode.Context)

{

command.CommandText = string.Concat("select set_config('request.headers','",headers,"',false)");

command.ExecuteNonQuery();

}

var shouldLog = options.LogCommands && logger != null;

StringBuilder? cmdLog = shouldLog ? new() : null;

int paramCount = 0;

for (var i = 0; i < parameters.Length; i++)

{

var parameter = parameters[i];

if (parameter is not null)

{

command.Parameters.Add(parameter);

paramCount++;

if (shouldLog)

{

object value = parameter.NpgsqlValue!;

var p = ParameterParser.FormatParam(ref value, ref routine.ParamTypeDescriptor[i]);

cmdLog!.AppendLine(string.Concat(

"-- $",

paramCount.ToString(),

" ", routine.ParamTypeDescriptor[i].OriginalType,

" = ",

p));

}

}

}

command.CommandText = routine.Expressions[paramCount];

if (shouldLog)

{

cmdLog!.AppendLine(command.CommandText);

LogInfo(ref logger, ref options, cmdLog.ToString());

}

if (endpoint.CommandTimeout.HasValue)

{

command.CommandTimeout = endpoint.CommandTimeout.Value;

}

//command callback

if (options.CommandCallbackAsync is not null)

{

await options.CommandCallbackAsync((routine, command, context));

if (context.Response.HasStarted || context.Response.StatusCode != (int)HttpStatusCode.OK)

{

return;

}

}

if (routine.IsVoid)

{

await command.ExecuteNonQueryAsync();

context.Response.StatusCode = (int)HttpStatusCode.NoContent;

await context.Response.CompleteAsync();

return;

}

else

{

command.AllResultTypesAreUnknown = true;

await using var reader = await command.ExecuteReaderAsync();

if (routine.ReturnsRecord == false)

{

if (await reader.ReadAsync())

{

string? value = reader.GetValue(0) as string;

TypeDescriptor descriptor = routine.ReturnTypeDescriptor[0];

if (endpoint.ResponseContentType is not null)

{

context.Response.ContentType = endpoint.ResponseContentType;

}

else if (descriptor.IsJson || descriptor.IsArray)

{

context.Response.ContentType = Application.Json;

}

else

{

context.Response.ContentType = Text.Plain;

}

if (endpoint.ResponseHeaders.Count > 0)

{

foreach ((string headerKey, StringValues headerValue) in endpoint.ResponseHeaders)

{

context.Response.Headers.Append(headerKey, headerValue);

}

}

context.Response.StatusCode = (int)HttpStatusCode.OK;

if (descriptor.IsArray && value is not null)

{

value = PgConverters.PgArrayToJsonArray(ref value, ref descriptor);

}

if (value is not null)

{

await context.Response.WriteAsync(value);

}

await context.Response.CompleteAsync();

return;

}

else

{

LogError(ref logger, ref options,

"Could not read a value from {0} \"{1}\" mapped to {2} {3} ",

routine.Type.ToString().ToLower(),

command.CommandText,

context.Request.Method,

context.Request.Path);

context.Response.StatusCode = (int)HttpStatusCode.InternalServerError;

await context.Response.CompleteAsync();

return;

}

}

else

{

if (endpoint.ResponseContentType is not null)

{

context.Response.ContentType = endpoint.ResponseContentType;

}

else

{

context.Response.ContentType = Application.Json;

}

if (endpoint.ResponseHeaders.Count > 0)

{

foreach (var (headerKey, headerValue) in endpoint.ResponseHeaders)

{

context.Response.Headers.Append(headerKey, headerValue);

}

}

context.Response.StatusCode = (int)HttpStatusCode.OK;

await context.Response.WriteAsync("[");

bool first = true;

while (await reader.ReadAsync())

{

if (!first)

{

await context.Response.WriteAsync(",");

}

else

{

first = false;

}

for (var i = 0; i < routine.ReturnRecordCount; i++)

{

object value = reader.GetValue(i);

// AllResultTypesAreUnknown = true always returns string, except for null

string raw = value == DBNull.Value ? "" : (string)value;

if (routine.ReturnsUnnamedSet == false)

{

if (i == 0)

{

await context.Response.WriteAsync("{");

}

await context.Response.WriteAsync(string.Concat("\"", endpoint.ReturnRecordNames[i], "\":"));

}

var descriptor = routine.ReturnTypeDescriptor[i];

if (value == DBNull.Value)

{

await context.Response.WriteAsync("null");

}

else if (descriptor.IsArray && value is not null)

{

raw = PgConverters.PgArrayToJsonArray(ref raw, ref descriptor);

await context.Response.WriteAsync(raw);

}

else if ((descriptor.IsNumeric || descriptor.IsBoolean || descriptor.IsJson) && value is not null)

{

if (descriptor.IsBoolean)

{

if (string.Equals(raw, "t", StringComparison.Ordinal))

{

await context.Response.WriteAsync("true");

}

else if (string.Equals(raw, "f", StringComparison.Ordinal))

{

await context.Response.WriteAsync("false");

}

else

{

await context.Response.WriteAsync(raw);

}

}

else

{

// numeric and json

await context.Response.WriteAsync(raw);

}

}

else

{

if (descriptor.ActualDbType == NpgsqlDbType.Unknown)

{

await context.Response.WriteAsync(PgConverters.PgUnknownToJsonArray(ref raw));

}

else if (descriptor.NeedsEscape)

{

await context.Response.WriteAsync(PgConverters.SerializeString(ref raw));

}

else

{

if (descriptor.IsDateTime)

{

await context.Response.WriteAsync(string.Concat("\"", raw.Replace(' ', 'T'), "\""));

}

else

{

await context.Response.WriteAsync(string.Concat("\"", raw, "\""));

}

}

}

if (routine.ReturnsUnnamedSet == false && i == routine.ReturnRecordCount - 1)

{

await context.Response.WriteAsync("}");

}

if (i < routine.ReturnRecordCount - 1)

{

await context.Response.WriteAsync(",");

}

}

}

await context.Response.WriteAsync("]");

await context.Response.CompleteAsync();

return;

}

}

}

finally

{

if (connection is not null && options.ConnectionFromServiceProvider is false)

{

await connection.DisposeAsync();

}

}

}

await next(context);

return;

async Task ParseJsonBody()

{

if (jsonObj is null)

{

context.Request.EnableBuffering();

context.Request.Body.Position = 0;

if (body is null)

{

using var reader = new StreamReader(context.Request.Body, Encoding.UTF8, detectEncodingFromByteOrderMarks: false, leaveOpen: true);

body = await reader.ReadToEndAsync();

}

JsonNode? node;

try

{

node = JsonNode.Parse(string.IsNullOrWhiteSpace(body) ? "{}" : body);

}

catch (JsonException)

{

LogWarning(ref logger, ref options, "Could not parse JSON body {0}, skipping path {1}.", body, context.Request.Path);

return;

}

try

{

jsonObj = node?.AsObject();

}

catch (InvalidOperationException)

{

LogWarning(ref logger, ref options, "Could not parse JSON body {0}, skipping path {1}.", body, context.Request.Path);

}

}

}

});

return builder;

}

private static FrozenDictionary<string, (Routine routine, RoutineEndpoint endpoint)[]> BuildDictionary(

IApplicationBuilder builder,

NpgsqlRestOptions options,

ILogger? logger)

{

var dict = new Dictionary<string, List<(Routine routine, RoutineEndpoint endpoint)>>();

var httpFile = new HttpFile(builder, options, logger);

foreach (var routine in RoutineQuery.Run(options))

{

RoutineEndpoint? result = DefaultEndpoint.Create(routine, options, logger);

if (result is null)

{

continue;

}

if (options.EndpointCreated is not null)

{

result = options.EndpointCreated(routine, result.Value);

}

if (result is null)

{

continue;

}

RoutineEndpoint endpoint = result.Value;

if (endpoint.BodyParameterName is not null && endpoint.RequestParamType == RequestParamType.BodyJson)

{

endpoint = endpoint with { RequestParamType = RequestParamType.QueryString };

LogWarning(ref logger, ref options,

"Endpoint {0} {1} changed request parameter type from body to query string because body will be used for parameter named `{2}`.",

endpoint.Method.ToString(),

endpoint.Url,

endpoint.BodyParameterName);

}

List<(Routine routine, RoutineEndpoint meta)> list = dict.TryGetValue(endpoint.Url, out var value) ? value : [];

list.Add((routine, endpoint));

dict[endpoint.Url] = list;

httpFile.HandleEntry(routine, endpoint);

if (options.LogEndpointCreatedInfo)

{

LogInfo(ref logger, ref options, "Created endpoint {0} {1}", endpoint.Method.ToString(), endpoint.Url);

}

}

if (options.EndpointsCreated is not null)

{

options.EndpointsCreated(dict.Values.SelectMany(x => x).ToArray());

}

httpFile.FinalizeHttpFile();

return dict

.ToDictionary(

x => x.Key,

x => x.Value.ToArray())

.ToFrozenDictionary();

}