const (
	DefaultCollectorPath       = "/_rpc/v1/reports/binary"
	DefaultPlainPort           = 80
	DefaultSecurePort          = 443
	DefaultThriftCollectorHost = "collector.lightstep.com"
	DefaultGRPCCollectorHost   = "collector-grpc.lightstep.com"

	DefaultMaxReportingPeriod = 2500 * time.Millisecond
	DefaultMinReportingPeriod = 500 * time.Millisecond
	DefaultMaxSpans           = 1000
	DefaultReportTimeout      = 30 * time.Second
	DefaultReconnectPeriod    = 5 * time.Minute

	DefaultMaxLogKeyLen   = 256
	DefaultMaxLogValueLen = 1024
	DefaultMaxLogsPerSpan = 500

	DefaultGRPCMaxCallSendMsgSizeBytes = math.MaxInt32
)

const (
	ParentSpanGUIDKey = "parent_span_guid" // ParentSpanGUIDKey is the tag key used to record the relationship between child and parent spans.
	ComponentNameKey  = "lightstep.component_name"
	GUIDKey           = "lightstep.guid" // <- runtime guid, not span guid
	HostnameKey       = "lightstep.hostname"
	CommandLineKey    = "lightstep.command_line"

	TracerPlatformKey        = "lightstep.tracer_platform"
	TracerPlatformValue      = "go"
	TracerPlatformVersionKey = "lightstep.tracer_platform_version"
	TracerVersionKey         = "lightstep.tracer_version" // Note: TracerVersionValue is generated from ./VERSION
)

const BinaryCarrier = "lightstep_binary_carrier"

const TracerVersionValue = "0.14.0"

type Connection interface {
	io.Closer
}

type ConnectorFactory func() (interface{}, Connection, error)

type Endpoint struct {
	Host      string `yaml:"host" usage:"host on which the endpoint is running"`
	Port      int    `yaml:"port" usage:"port on which the endpoint is listening"`
	Plaintext bool   `yaml:"plaintext" usage:"whether or not to encrypt data send to the endpoint"`
}

type Options struct {
	// AccessToken is the unique API key for your LightStep project.  It is
	// available on your account page at https://app.lightstep.com/account
	AccessToken string `yaml:"access_token" usage:"access token for reporting to LightStep"`

	// Collector is the host, port, and plaintext option to use
	// for the collector.
	Collector Endpoint `yaml:"collector"`

	// Tags are arbitrary key-value pairs that apply to all spans generated by
	// this Tracer.
	Tags ot.Tags

	// LightStep is the host, port, and plaintext option to use
	// for the LightStep web API.
	LightStepAPI Endpoint `yaml:"lightstep_api"`

	// MaxBufferedSpans is the maximum number of spans that will be buffered
	// before sending them to a collector.
	MaxBufferedSpans int `yaml:"max_buffered_spans"`

	// MaxLogKeyLen is the maximum allowable size (in characters) of an
	// OpenTracing logging key. Longer keys are truncated.
	MaxLogKeyLen int `yaml:"max_log_key_len"`

	// MaxLogValueLen is the maximum allowable size (in characters) of an
	// OpenTracing logging value. Longer values are truncated. Only applies to
	// variable-length value types (strings, interface{}, etc).
	MaxLogValueLen int `yaml:"max_log_value_len"`

	// MaxLogsPerSpan limits the number of logs in a single span.
	MaxLogsPerSpan int `yaml:"max_logs_per_span"`

	// GRPCMaxCallSendMsgSizeBytes limits the size in bytes of grpc messages
	// sent by a client.
	GRPCMaxCallSendMsgSizeBytes int `yaml:"grpc_max_call_send_msg_size_bytes"`

	// ReportingPeriod is the maximum duration of time between sending spans
	// to a collector.  If zero, the default will be used.
	ReportingPeriod time.Duration `yaml:"reporting_period"`

	// MinReportingPeriod is the minimum duration of time between sending spans
	// to a collector.  If zero, the default will be used. It is strongly
	// recommended to use the default.
	MinReportingPeriod time.Duration `yaml:"min_reporting_period"`

	ReportTimeout time.Duration `yaml:"report_timeout"`

	// DropSpanLogs turns log events on all Spans into no-ops.
	DropSpanLogs bool `yaml:"drop_span_logs"`

	// Set Verbose to true to enable more text logging.
	Verbose bool `yaml:"verbose"`

	// Force the use of a specific transport protocol.
	// If multiple are set to true, the following order is used to select for the first option: thrift, http, grpc.
	// If none are set to true, GRPC is defaulted to.
	UseThrift bool `yaml:"use_thrift"`
	UseHttp   bool `yaml:"use_http"`
	UseGRPC   bool `yaml:"usegrpc"`

	ReconnectPeriod time.Duration `yaml:"reconnect_period"`

	// A hook for receiving finished span events
	Recorder SpanRecorder `yaml:"-" json:"-"`

	// For testing purposes only
	ConnFactory ConnectorFactory `yaml:"-" json:"-"`
}

type RawSpan struct {
	// Those recording the RawSpan should also record the contents of its
	// SpanContext.
	Context SpanContext

	// The SpanID of this SpanContext's first intra-trace reference (i.e.,
	// "parent"), or 0 if there is no parent.
	ParentSpanID uint64

	// The name of the "operation" this span is an instance of. (Called a "span
	// name" in some implementations)
	Operation string

	// We store <start, duration> rather than <start, end> so that only
	// one of the timestamps has global clock uncertainty issues.
	Start    time.Time
	Duration time.Duration

	// Essentially an extension mechanism. Can be used for many purposes,
	// not to be enumerated here.
	Tags opentracing.Tags

	// The span's "microlog".
	Logs []opentracing.LogRecord
}

type SetParentSpanID uint64

type SetSpanID uint64

type SetTraceID uint64

type SpanContext struct {
	// A probabilistically unique identifier for a [multi-span] trace.
	TraceID uint64

	// A probabilistically unique identifier for a span.
	SpanID uint64

	// The span's associated baggage.
	Baggage map[string]string // initialized on first use
}

type SpanRecorder interface {
	RecordSpan(RawSpan)
}

type Tracer interface {
	ot.Tracer

	// Close flushes and then terminates the LightStep collector
	Close() error
	// Flush sends all spans currently in the buffer to the LighStep collector
	Flush()
	// Options gets the Options used in New() or NewWithOptions().
	Options() Options
	// Disable prevents the tracer from recording spans or flushing
	Disable()
}