package bench

import "context"

// Benchmark is an interface to guide the creation of new pilosa benchmarks or
// benchmark components. It defines 2 methods, Init, and Run. These are separate
// methods so that benchmark running code can time only the running of the
// benchmark, and not any setup.
type Benchmark interface {
	// Init takes a list of hosts and an agent number. It is generally expected
	// to set up a connection to pilosa using whatever client it chooses. The
	// agentNum should be used to parameterize the benchmark's configuration if
	// it is being run simultaneously on multiple "agents". E.G. the agentNum
	// might be used to make a random seed different for each agent, or have
	// each agent set a different set of bits. Init's doc string should document
	// how the agentNum affects it. Every benchmark should have a 'Name' field
	// set by init, which appears when the benchmark is marshalled to json as
	// "name".
	Init(hosts []string, agentNum int) error

	// Run runs the benchmark. The return value of Run is kept generic so that
	// any relevant statistics or metrics that may be specific to the benchmark
	// in question can be reported. TODO guidelines for what gets included in
	// results and what will get added by other stuff. Run does not need to
	// report total run time in `results`, as that will be added by calling
	// code.
	Run(ctx context.Context) map[string]interface{}
}

// Command extends Benchmark by adding methods for configuring via command line flags and returning usage information.
type Command interface {
	Benchmark

	// ConsumeFlags sets and parses flags, and then returns flagSet.Args(). This
	// is so that multiple benchmarks can be specified at the command line.
	ConsumeFlags(args []string) ([]string, error)

	// Usage returns information on how to use this benchmark. The usage string
	// should explain how the agent num affects the benchmark's operation.
	Usage() string
}