package chains

import "errors"

var (
	// ErrInvalidInputValues is returned if the input values to a chain is invalid.
	ErrInvalidInputValues = errors.New("invalid input values")
	// ErrMissingInputValues is returned when some expected input values keys to
	// a chain is missing.
	ErrMissingInputValues = errors.New("missing key in input values")
	// ErrInputValuesWrongType is returned if an input value to a chain is of
	// wrong type.
	ErrInputValuesWrongType = errors.New("input key is of wrong type")
	// ErrMissingMemoryKeyValues is returned when some expected input values keys to
	// a chain is missing.
	ErrMissingMemoryKeyValues = errors.New("missing memory key in input values")
	// ErrMemoryValuesWrongType is returned if the memory value to a chain is of
	// wrong type.
	ErrMemoryValuesWrongType = errors.New("memory key is of wrong type")
	// ErrInvalidOutputValues is returned when expected output keys to a chain does
	// not match the actual keys in the return output values map.
	ErrInvalidOutputValues = errors.New("missing key in output values")

	// ErrMultipleInputsInRun is returned in the run function if the chain expects
	// more then one input values.
	ErrMultipleInputsInRun = errors.New("run not supported in chain with more then one expected input")
	// ErrMultipleOutputsInRun is returned in the run function if the chain expects
	// more then one output values.
	ErrMultipleOutputsInRun = errors.New("run not supported in chain with more then one expected output")
	// ErrWrongOutputTypeInRun is returned in the run function if the chain returns
	// a value that is not a string.
	ErrWrongOutputTypeInRun = errors.New("run not supported in chain that returns value that is not string")

	// ErrOutputNotStringInPredict is returned if a chain does not return a string
	// in the predict function.
	ErrOutputNotStringInPredict = errors.New("predict is not supported with a chain that does not return a string")
	// ErrMultipleOutputsInPredict is returned if a chain has multiple return values
	// in predict.
	ErrMultipleOutputsInPredict = errors.New("predict is not supported with a chain that returns multiple values")
	// ErrChainInitialization is returned if a chain is not initialized appropriately.
	ErrChainInitialization = errors.New("error initializing chain")
)