jormun-db/main.odin

package main

import "core:encoding/json"
import "core:fmt"
import "core:mem"
import "core:os"
import "core:strconv"
import "core:strings"
import "dynamodb"

Config :: struct {
	host:     string,
	port:     int,
	data_dir: string,
	verbose:  bool,
}

main :: proc() {
	// Parse configuration
	config := parse_config()

	// Print banner
	print_banner(config)

	// Create data directory
	os.make_directory(config.data_dir)

	// Initialize storage engine
	engine, err := dynamodb.storage_engine_init(context.allocator, config.data_dir)
	if err != .None {
		fmt.eprintln("Failed to initialize storage:", err)
		os.exit(1)
	}
	defer dynamodb.storage_engine_destroy(engine)

	fmt.printfln("Storage engine initialized at %s", config.data_dir)
	fmt.printfln("Starting DynamoDB-compatible server on %s:%d", config.host, config.port)

	// Create HTTP server
	server_config := default_server_config()

	server, server_ok := server_init(
		context.allocator,
		config.host,
		config.port,
		handle_dynamodb_request,
		engine,
		server_config,
	)

	if !server_ok {
		fmt.eprintln("Failed to initialize HTTP server")
		os.exit(1)
	}
	defer server_stop(&server)

	fmt.println("Ready to accept connections!")

	// Start server (blocks)
	if !server_start(&server) {
		fmt.eprintln("Server failed to start")
		os.exit(1)
	}
}

// DynamoDB request handler - called for each HTTP request with request-scoped arena allocator
handle_dynamodb_request :: proc(ctx: rawptr, request: ^HTTP_Request, request_alloc: mem.Allocator) -> HTTP_Response {
	engine := cast(^dynamodb.Storage_Engine)ctx

	// All allocations in this function use the request arena automatically
	response := response_init(request_alloc)
	response_add_header(&response, "Content-Type", "application/x-amz-json-1.0")
	response_add_header(&response, "x-amzn-RequestId", "local-request-id")

	// Get X-Amz-Target header to determine operation
	target := request_get_header(request, "X-Amz-Target")
	if target == nil {
		return make_error_response(&response, .SerializationException, "Missing X-Amz-Target header")
	}

	operation := dynamodb.operation_from_target(target.?)

	// Route to appropriate handler
	#partial switch operation {
	case .CreateTable:
		handle_create_table(engine, request, &response)
	case .DeleteTable:
		handle_delete_table(engine, request, &response)
	case .DescribeTable:
		handle_describe_table(engine, request, &response)
	case .ListTables:
		handle_list_tables(engine, request, &response)
	case .PutItem:
		handle_put_item(engine, request, &response)
	case .GetItem:
		handle_get_item(engine, request, &response)
	case .DeleteItem:
		handle_delete_item(engine, request, &response)
	case .UpdateItem:
		handle_update_item(engine, request, &response)
	case .Query:
		handle_query(engine, request, &response)
	case .Scan:
		handle_scan(engine, request, &response)
	case .Unknown:
		return make_error_response(&response, .ValidationException, "Unknown operation")
	case:
		return make_error_response(&response, .ValidationException, "Operation not implemented")
	}

	return response
}

// ============================================================================
// Table Operations
// ============================================================================

handle_create_table :: proc(engine: ^dynamodb.Storage_Engine, request: ^HTTP_Request, response: ^HTTP_Response) {
	// Parse JSON body
	data, parse_err := json.parse(request.body, allocator = context.allocator)
	if parse_err != nil {
		make_error_response(response, .SerializationException, "Invalid JSON")
		return
	}
	defer json.destroy_value(data)

	root, ok := data.(json.Object)
	if !ok {
		make_error_response(response, .SerializationException, "Request must be an object")
		return
	}

	// Extract TableName
	table_name_val, found := root["TableName"]
	if !found {
		make_error_response(response, .ValidationException, "Missing TableName")
		return
	}

	table_name, name_ok := table_name_val.(json.String)
	if !name_ok {
		make_error_response(response, .ValidationException, "TableName must be a string")
		return
	}

	// Parse KeySchema
	key_schema, ks_err := parse_key_schema(root)
	if ks_err != .None {
		msg := key_schema_error_message(ks_err)
		make_error_response(response, .ValidationException, msg)
		return
	}

	// Parse AttributeDefinitions
	attr_defs, ad_err := parse_attribute_definitions(root)
	if ad_err != .None {
		msg := attribute_definitions_error_message(ad_err)
		make_error_response(response, .ValidationException, msg)
		return
	}

	// Validate that key attributes are defined
	if !validate_key_attributes_defined(key_schema, attr_defs) {
		make_error_response(response, .ValidationException, "Key attribute not defined in AttributeDefinitions")
		return
	}

	// Create the table
	desc, create_err := dynamodb.create_table(engine, string(table_name), key_schema, attr_defs)
	if create_err != .None {
		#partial switch create_err {
		case .Table_Already_Exists:
			make_error_response(response, .ResourceInUseException, "Table already exists")
		case:
			make_error_response(response, .InternalServerError, "Failed to create table")
		}
		return
	}

	// Build response
	resp_body := fmt.aprintf(
		`{{"TableDescription":{{"TableName":"%s","TableStatus":"%s","CreationDateTime":%d}}}}`,
		desc.table_name,
		dynamodb.table_status_to_string(desc.table_status),
		desc.creation_date_time,
	)

	response_set_body(response, transmute([]byte)resp_body)
}

handle_delete_table :: proc(engine: ^dynamodb.Storage_Engine, request: ^HTTP_Request, response: ^HTTP_Response) {
	table_name, ok := dynamodb.parse_table_name(request.body)
	if !ok {
		make_error_response(response, .ValidationException, "Invalid request or missing TableName")
		return
	}

	err := dynamodb.delete_table(engine, table_name)
	if err != .None {
		#partial switch err {
		case .Table_Not_Found:
			make_error_response(response, .ResourceNotFoundException, "Table not found")
		case:
			make_error_response(response, .InternalServerError, "Failed to delete table")
		}
		return
	}

	resp_body := fmt.aprintf(`{{"TableDescription":{{"TableName":"%s","TableStatus":"DELETING"}}}}`, table_name)
	response_set_body(response, transmute([]byte)resp_body)
}

handle_describe_table :: proc(engine: ^dynamodb.Storage_Engine, request: ^HTTP_Request, response: ^HTTP_Response) {
	table_name, ok := dynamodb.parse_table_name(request.body)
	if !ok {
		make_error_response(response, .ValidationException, "Invalid request or missing TableName")
		return
	}

	metadata, err := dynamodb.get_table_metadata(engine, table_name)
	if err != .None {
		#partial switch err {
		case .Table_Not_Found:
			make_error_response(response, .ResourceNotFoundException, "Table not found")
		case:
			make_error_response(response, .InternalServerError, "Failed to describe table")
		}
		return
	}
	defer dynamodb.table_metadata_destroy(&metadata, engine.allocator)

	// Build response with key schema
	builder := strings.builder_make()
	strings.write_string(&builder, `{"Table":{"TableName":"`)
	strings.write_string(&builder, metadata.table_name)
	strings.write_string(&builder, `","TableStatus":"`)
	strings.write_string(&builder, dynamodb.table_status_to_string(metadata.table_status))
	strings.write_string(&builder, `","CreationDateTime":`)
	fmt.sbprintf(&builder, "%d", metadata.creation_date_time)
	strings.write_string(&builder, `,"KeySchema":[`)

	for ks, i in metadata.key_schema {
		if i > 0 do strings.write_string(&builder, ",")
		fmt.sbprintf(&builder, `{"AttributeName":"%s","KeyType":"%s"}`,
			ks.attribute_name, dynamodb.key_type_to_string(ks.key_type))
	}

	strings.write_string(&builder, `],"AttributeDefinitions":[`)

	for ad, i in metadata.attribute_definitions {
		if i > 0 do strings.write_string(&builder, ",")
		fmt.sbprintf(&builder, `{"AttributeName":"%s","AttributeType":"%s"}`,
			ad.attribute_name, dynamodb.scalar_type_to_string(ad.attribute_type))
	}

	strings.write_string(&builder, `]}}`)

	resp_body := strings.to_string(builder)
	response_set_body(response, transmute([]byte)resp_body)
}

handle_list_tables :: proc(engine: ^dynamodb.Storage_Engine, request: ^HTTP_Request, response: ^HTTP_Response) {
	_ = request

	tables, err := dynamodb.list_tables(engine)
	if err != .None {
		make_error_response(response, .InternalServerError, "Failed to list tables")
		return
	}

	builder := strings.builder_make()
	strings.write_string(&builder, `{"TableNames":[`)

	for table, i in tables {
		if i > 0 do strings.write_string(&builder, ",")
		fmt.sbprintf(&builder, `"%s"`, table)
	}

	strings.write_string(&builder, `]}`)

	resp_body := strings.to_string(builder)
	response_set_body(response, transmute([]byte)resp_body)
}

// ============================================================================
// Item Operations
// ============================================================================

handle_put_item :: proc(engine: ^dynamodb.Storage_Engine, request: ^HTTP_Request, response: ^HTTP_Response) {
	table_name, ok := dynamodb.parse_table_name(request.body)
	if !ok {
		make_error_response(response, .ValidationException, "Invalid request or missing TableName")
		return
	}

	item, item_ok := dynamodb.parse_item_from_request(request.body)
	if !item_ok {
		make_error_response(response, .ValidationException, "Invalid or missing Item")
		return
	}
	defer dynamodb.item_destroy(&item)

	err := dynamodb.put_item(engine, table_name, item)
	if err != .None {
		handle_storage_error(response, err)
		return
	}

	response_set_body(response, transmute([]byte)string("{}"))
}

handle_get_item :: proc(engine: ^dynamodb.Storage_Engine, request: ^HTTP_Request, response: ^HTTP_Response) {
	table_name, ok := dynamodb.parse_table_name(request.body)
	if !ok {
		make_error_response(response, .ValidationException, "Invalid request or missing TableName")
		return
	}

	key, key_ok := dynamodb.parse_key_from_request(request.body)
	if !key_ok {
		make_error_response(response, .ValidationException, "Invalid or missing Key")
		return
	}
	defer dynamodb.item_destroy(&key)

	item, err := dynamodb.get_item(engine, table_name, key)
	if err != .None {
		handle_storage_error(response, err)
		return
	}

	if item_val, has_item := item.?; has_item {
		defer dynamodb.item_destroy(&item_val)
		item_json := dynamodb.serialize_item(item_val)
		resp := fmt.aprintf(`{"Item":%s}`, item_json)
		response_set_body(response, transmute([]byte)resp)
	} else {
		response_set_body(response, transmute([]byte)string("{}"))
	}
}

handle_delete_item :: proc(engine: ^dynamodb.Storage_Engine, request: ^HTTP_Request, response: ^HTTP_Response) {
	table_name, ok := dynamodb.parse_table_name(request.body)
	if !ok {
		make_error_response(response, .ValidationException, "Invalid request or missing TableName")
		return
	}

	key, key_ok := dynamodb.parse_key_from_request(request.body)
	if !key_ok {
		make_error_response(response, .ValidationException, "Invalid or missing Key")
		return
	}
	defer dynamodb.item_destroy(&key)

	err := dynamodb.delete_item(engine, table_name, key)
	if err != .None {
		handle_storage_error(response, err)
		return
	}

	response_set_body(response, transmute([]byte)string("{}"))
}

// UpdateItem — minimal stub: supports SET for scalar attributes
handle_update_item :: proc(engine: ^dynamodb.Storage_Engine, request: ^HTTP_Request, response: ^HTTP_Response) {
	// TODO: Implement UpdateExpression parsing (SET x = :val, REMOVE y, etc.)
	// For now, return a clear error so callers know it's not yet supported.
	make_error_response(response, .ValidationException,
		"UpdateItem is not yet supported. Use PutItem to replace the full item.")
}

// ============================================================================
// Query and Scan Operations
// ============================================================================

handle_query :: proc(engine: ^dynamodb.Storage_Engine, request: ^HTTP_Request, response: ^HTTP_Response) {
	table_name, ok := dynamodb.parse_table_name(request.body)
	if !ok {
		make_error_response(response, .ValidationException, "Invalid request or missing TableName")
		return
	}

	// ---- Fetch table metadata early so we can parse ExclusiveStartKey ----
	metadata, meta_err := dynamodb.get_table_metadata(engine, table_name)
	if meta_err != .None {
		handle_storage_error(response, meta_err)
		return
	}
	defer dynamodb.table_metadata_destroy(&metadata, engine.allocator)

	// Parse KeyConditionExpression
	kc, kc_ok := dynamodb.parse_query_key_condition(request.body)
	if !kc_ok {
		make_error_response(response, .ValidationException, "Missing or invalid KeyConditionExpression")
		return
	}
	defer dynamodb.key_condition_destroy(&kc)

	// Extract partition key bytes
	pk_bytes, pk_ok := dynamodb.key_condition_get_pk_bytes(&kc)
	if !pk_ok {
		make_error_response(response, .ValidationException, "Invalid partition key type")
		return
	}

	// Clone pk_bytes so it survives kc cleanup (kc borrows from the parsed value)
	pk_owned := make([]byte, len(pk_bytes))
	copy(pk_owned, pk_bytes)
	defer delete(pk_owned)

	// Parse Limit
	limit := dynamodb.parse_limit(request.body)
	if limit == 0 {
		limit = 100
	}

	// ---- Parse ExclusiveStartKey with proper type handling ----
	exclusive_start_key, esk_ok := dynamodb.parse_exclusive_start_key(
		request.body, table_name, metadata.key_schema,
	)
	if !esk_ok {
		make_error_response(response, .ValidationException, "Invalid ExclusiveStartKey")
		return
	}
	defer {
		if esk, has_esk := exclusive_start_key.?; has_esk {
			delete(esk)
		}
	}

	// ---- Pass sort key condition through to storage layer ----
	sk_condition: Maybe(dynamodb.Sort_Key_Condition) = nil
	if skc, has_skc := kc.sk_condition.?; has_skc {
		sk_condition = skc
	}

	result, err := dynamodb.query(engine, table_name, pk_owned, exclusive_start_key, limit, sk_condition)
	if err != .None {
		handle_storage_error(response, err)
		return
	}
	defer dynamodb.query_result_destroy(&result)

	// Build response with proper pagination
	write_items_response_with_pagination(response, result.items, result.last_evaluated_key, &metadata)
}

handle_scan :: proc(engine: ^dynamodb.Storage_Engine, request: ^HTTP_Request, response: ^HTTP_Response) {
	table_name, ok := dynamodb.parse_table_name(request.body)
	if !ok {
		make_error_response(response, .ValidationException, "Invalid request or missing TableName")
		return
	}

	// ---- Fetch table metadata early so we can parse ExclusiveStartKey ----
	metadata, meta_err := dynamodb.get_table_metadata(engine, table_name)
	if meta_err != .None {
		handle_storage_error(response, meta_err)
		return
	}
	defer dynamodb.table_metadata_destroy(&metadata, engine.allocator)

	// Parse Limit (default to 100 if not specified)
	limit := dynamodb.parse_limit(request.body)
	if limit == 0 {
		limit = 100
	}

	// ---- Parse ExclusiveStartKey with proper type handling ----
	exclusive_start_key, esk_ok := dynamodb.parse_exclusive_start_key(
		request.body, table_name, metadata.key_schema,
	)
	if !esk_ok {
		make_error_response(response, .ValidationException, "Invalid ExclusiveStartKey")
		return
	}
	defer {
		if esk, has_esk := exclusive_start_key.?; has_esk {
			delete(esk)
		}
	}

	// Perform scan
	result, err := dynamodb.scan(engine, table_name, exclusive_start_key, limit)
	if err != .None {
		handle_storage_error(response, err)
		return
	}
	defer dynamodb.scan_result_destroy(&result)

	// Build response with proper pagination
	write_items_response_with_pagination(response, result.items, result.last_evaluated_key, &metadata)
}

// ============================================================================
// Shared Pagination Response Builder
//
// Mirrors the Zig writeItemsResponseWithPagination helper:
//   - Serializes Items array
//   - Emits Count / ScannedCount
//   - Decodes binary last_evaluated_key → DynamoDB JSON LastEvaluatedKey
// ============================================================================

write_items_response_with_pagination :: proc(
	response: ^HTTP_Response,
	items: []dynamodb.Item,
	last_evaluated_key_binary: Maybe([]byte),
	metadata: ^dynamodb.Table_Metadata,
) {
	builder := strings.builder_make()
	strings.write_string(&builder, `{"Items":[`)

	for item, i in items {
		if i > 0 do strings.write_string(&builder, ",")
		item_json := dynamodb.serialize_item(item)
		strings.write_string(&builder, item_json)
	}

	strings.write_string(&builder, `],"Count":`)
	fmt.sbprintf(&builder, "%d", len(items))
	strings.write_string(&builder, `,"ScannedCount":`)
	fmt.sbprintf(&builder, "%d", len(items))

	// Emit LastEvaluatedKey if the storage layer produced one
	if binary_key, has_last := last_evaluated_key_binary.?; has_last {
		lek_json, lek_ok := dynamodb.serialize_last_evaluated_key(binary_key, metadata)
		if lek_ok {
			strings.write_string(&builder, `,"LastEvaluatedKey":`)
			strings.write_string(&builder, lek_json)
		}
		// If decoding fails we still return the items — just without a pagination token.
		// The client will assume the scan/query is complete.
	}

	strings.write_string(&builder, "}")

	resp_body := strings.to_string(builder)
	response_set_body(response, transmute([]byte)resp_body)
}

// ============================================================================
// Centralized Storage Error → DynamoDB Error mapping
//
// Maps storage errors to the correct DynamoDB error type AND HTTP status code.
// DynamoDB uses:
//   400 — ValidationException, ResourceNotFoundException, ResourceInUseException, etc.
//   500 — InternalServerError
// ============================================================================

handle_storage_error :: proc(response: ^HTTP_Response, err: dynamodb.Storage_Error) {
	#partial switch err {
	case .Table_Not_Found:
		make_error_response(response, .ResourceNotFoundException, "Requested resource not found")
	case .Table_Already_Exists:
		make_error_response(response, .ResourceInUseException, "Table already exists")
	case .Missing_Key_Attribute:
		make_error_response(response, .ValidationException, "One or more required key attributes are missing")
	case .Invalid_Key:
		make_error_response(response, .ValidationException, "Invalid key: type mismatch or malformed key value")
	case .Serialization_Error:
		make_error_response(response, .InternalServerError, "Internal serialization error")
	case .RocksDB_Error:
		make_error_response(response, .InternalServerError, "Internal storage error")
	case .Out_Of_Memory:
		make_error_response(response, .InternalServerError, "Internal memory error")
	case:
		make_error_response(response, .InternalServerError, "Unexpected error")
	}
}

// ============================================================================
// Schema Parsing Helpers
// ============================================================================

Key_Schema_Error :: enum {
	None,
	Missing_Key_Schema,
	Invalid_Key_Schema,
	No_Hash_Key,
	Multiple_Hash_Keys,
	Multiple_Range_Keys,
	Invalid_Key_Type,
}

parse_key_schema :: proc(root: json.Object) -> ([]dynamodb.Key_Schema_Element, Key_Schema_Error) {
	key_schema_val, found := root["KeySchema"]
	if !found do return nil, .Missing_Key_Schema

	key_schema_array, ok := key_schema_val.(json.Array)
	if !ok do return nil, .Invalid_Key_Schema

	if len(key_schema_array) == 0 || len(key_schema_array) > 2 {
		return nil, .Invalid_Key_Schema
	}

	key_schema := make([]dynamodb.Key_Schema_Element, len(key_schema_array))

	hash_count := 0
	range_count := 0

	for elem, i in key_schema_array {
		elem_obj, elem_ok := elem.(json.Object)
		if !elem_ok {
			for j in 0..<i {
				delete(key_schema[j].attribute_name)
			}
			delete(key_schema)
			return nil, .Invalid_Key_Schema
		}

		// Get AttributeName
		attr_name_val, attr_found := elem_obj["AttributeName"]
		if !attr_found {
			for j in 0..<i {
				delete(key_schema[j].attribute_name)
			}
			delete(key_schema)
			return nil, .Invalid_Key_Schema
		}

		attr_name, name_ok := attr_name_val.(json.String)
		if !name_ok {
			for j in 0..<i {
				delete(key_schema[j].attribute_name)
			}
			delete(key_schema)
			return nil, .Invalid_Key_Schema
		}

		// Get KeyType
		key_type_val, type_found := elem_obj["KeyType"]
		if !type_found {
			for j in 0..<i {
				delete(key_schema[j].attribute_name)
			}
			delete(key_schema)
			return nil, .Invalid_Key_Schema
		}

		key_type_str, type_ok := key_type_val.(json.String)
		if !type_ok {
			for j in 0..<i {
				delete(key_schema[j].attribute_name)
			}
			delete(key_schema)
			return nil, .Invalid_Key_Schema
		}

		key_type, kt_ok := dynamodb.key_type_from_string(string(key_type_str))
		if !kt_ok {
			for j in 0..<i {
				delete(key_schema[j].attribute_name)
			}
			delete(key_schema)
			return nil, .Invalid_Key_Type
		}

		// Count key types
		switch key_type {
		case .HASH:  hash_count += 1
		case .RANGE: range_count += 1
		}

		key_schema[i] = dynamodb.Key_Schema_Element{
			attribute_name = strings.clone(string(attr_name)),
			key_type       = key_type,
		}
	}

	// Validate key counts
	if hash_count == 0 {
		for ks in key_schema {
			delete(ks.attribute_name)
		}
		delete(key_schema)
		return nil, .No_Hash_Key
	}

	if hash_count > 1 {
		for ks in key_schema {
			delete(ks.attribute_name)
		}
		delete(key_schema)
		return nil, .Multiple_Hash_Keys
	}

	if range_count > 1 {
		for ks in key_schema {
			delete(ks.attribute_name)
		}
		delete(key_schema)
		return nil, .Multiple_Range_Keys
	}

	return key_schema, .None
}

key_schema_error_message :: proc(err: Key_Schema_Error) -> string {
	switch err {
	case .None:                  return ""
	case .Missing_Key_Schema:    return "Missing KeySchema"
	case .Invalid_Key_Schema:    return "Invalid KeySchema format"
	case .No_Hash_Key:           return "KeySchema must contain exactly one HASH key"
	case .Multiple_Hash_Keys:    return "KeySchema can only contain one HASH key"
	case .Multiple_Range_Keys:   return "KeySchema can only contain one RANGE key"
	case .Invalid_Key_Type:      return "Invalid KeyType (must be HASH or RANGE)"
	}
	return "Invalid KeySchema"
}

Attribute_Definitions_Error :: enum {
	None,
	Missing_Attribute_Definitions,
	Invalid_Attribute_Definitions,
	Invalid_Attribute_Type,
	Duplicate_Attribute_Name,
}

parse_attribute_definitions :: proc(root: json.Object) -> ([]dynamodb.Attribute_Definition, Attribute_Definitions_Error) {
	attr_defs_val, found := root["AttributeDefinitions"]
	if !found do return nil, .Missing_Attribute_Definitions

	attr_defs_array, ok := attr_defs_val.(json.Array)
	if !ok do return nil, .Invalid_Attribute_Definitions

	if len(attr_defs_array) == 0 {
		return nil, .Invalid_Attribute_Definitions
	}

	attr_defs := make([]dynamodb.Attribute_Definition, len(attr_defs_array))
	seen_names := make(map[string]bool, allocator = context.temp_allocator)
	defer delete(seen_names)

	for elem, i in attr_defs_array {
		elem_obj, elem_ok := elem.(json.Object)
		if !elem_ok {
			for j in 0..<i {
				delete(attr_defs[j].attribute_name)
			}
			delete(attr_defs)
			return nil, .Invalid_Attribute_Definitions
		}

		// Get AttributeName
		attr_name_val, attr_found := elem_obj["AttributeName"]
		if !attr_found {
			for j in 0..<i {
				delete(attr_defs[j].attribute_name)
			}
			delete(attr_defs)
			return nil, .Invalid_Attribute_Definitions
		}

		attr_name, name_ok := attr_name_val.(json.String)
		if !name_ok {
			for j in 0..<i {
				delete(attr_defs[j].attribute_name)
			}
			delete(attr_defs)
			return nil, .Invalid_Attribute_Definitions
		}

		// Check for duplicates
		if string(attr_name) in seen_names {
			for j in 0..<i {
				delete(attr_defs[j].attribute_name)
			}
			delete(attr_defs)
			return nil, .Duplicate_Attribute_Name
		}
		seen_names[string(attr_name)] = true

		// Get AttributeType
		attr_type_val, type_found := elem_obj["AttributeType"]
		if !type_found {
			for j in 0..<i {
				delete(attr_defs[j].attribute_name)
			}
			delete(attr_defs)
			return nil, .Invalid_Attribute_Definitions
		}

		attr_type_str, type_ok := attr_type_val.(json.String)
		if !type_ok {
			for j in 0..<i {
				delete(attr_defs[j].attribute_name)
			}
			delete(attr_defs)
			return nil, .Invalid_Attribute_Definitions
		}

		attr_type, at_ok := dynamodb.scalar_type_from_string(string(attr_type_str))
		if !at_ok {
			for j in 0..<i {
				delete(attr_defs[j].attribute_name)
			}
			delete(attr_defs)
			return nil, .Invalid_Attribute_Type
		}

		attr_defs[i] = dynamodb.Attribute_Definition{
			attribute_name = strings.clone(string(attr_name)),
			attribute_type = attr_type,
		}
	}

	return attr_defs, .None
}

attribute_definitions_error_message :: proc(err: Attribute_Definitions_Error) -> string {
	switch err {
	case .None:                              return ""
	case .Missing_Attribute_Definitions:     return "Missing AttributeDefinitions"
	case .Invalid_Attribute_Definitions:     return "Invalid AttributeDefinitions format"
	case .Invalid_Attribute_Type:            return "Invalid AttributeType (must be S, N, or B)"
	case .Duplicate_Attribute_Name:          return "Duplicate attribute name in AttributeDefinitions"
	}
	return "Invalid AttributeDefinitions"
}

validate_key_attributes_defined :: proc(key_schema: []dynamodb.Key_Schema_Element, attr_defs: []dynamodb.Attribute_Definition) -> bool {
	for ks in key_schema {
		found := false
		for ad in attr_defs {
			if ks.attribute_name == ad.attribute_name {
				found = true
				break
			}
		}
		if !found do return false
	}
	return true
}

// ============================================================================
// Error Response Helper
//
// Maps DynamoDB error types to correct HTTP status codes:
//   400 — ValidationException, ResourceNotFoundException, ResourceInUseException,
//          ConditionalCheckFailedException, SerializationException
//   500 — InternalServerError
// ============================================================================

make_error_response :: proc(response: ^HTTP_Response, err_type: dynamodb.DynamoDB_Error_Type, message: string) -> HTTP_Response {
	status: HTTP_Status

	#partial switch err_type {
	case .InternalServerError:
		status = .Internal_Server_Error
	case:
		status = .Bad_Request
	}

	response_set_status(response, status)
	error_body := dynamodb.error_to_response(err_type, message)
	response_set_body(response, transmute([]byte)error_body)
	return response^
}

// ============================================================================
// Configuration
// ============================================================================

parse_config :: proc() -> Config {
	config := Config{
		host = "0.0.0.0",
		port = 8002,
		data_dir = "./data",
		verbose = false,
	}

	// Environment variables
	if port_str, env_ok := os.lookup_env("JORMUN_PORT"); env_ok {
		if port, parse_ok := strconv.parse_int(port_str); parse_ok {
			config.port = port
		}
	}

	if host, ok := os.lookup_env("JORMUN_HOST"); ok {
		config.host = host
	}

	if data_dir, ok := os.lookup_env("JORMUN_DATA_DIR"); ok {
		config.data_dir = data_dir
	}

	if verbose, ok := os.lookup_env("JORMUN_VERBOSE"); ok {
		config.verbose = verbose == "1"
	}

	// TODO: Parse command line arguments

	return config
}

print_banner :: proc(config: Config) {
	banner := `
  ╔═══════════════════════════════════════════════╗
  ║                                               ║
  ║     ╦╔═╗╦═╗╔╦╗╦ ╦╔╗╔╔╦╗╔╗                      ║
  ║     ║║ ║╠╦╝║║║║ ║║║║ ║║╠╩╗                     ║
  ║    ╚╝╚═╝╩╚═╩ ╩╚═╝╝╚╝═╩╝╚═╝                     ║
  ║                                               ║
  ║   DynamoDB-Compatible Database                ║
  ║   Powered by RocksDB + Odin                   ║
  ║                                               ║
  ╚═══════════════════════════════════════════════╝
`
	fmt.println(banner)
	fmt.printfln("  Port: %d | Data Dir: %s\n", config.port, config.data_dir)
}