const (
    // Possible values for AlertState.
    AlertStateFiring   AlertState = "firing"
    AlertStateInactive AlertState = "inactive"
    AlertStatePending  AlertState = "pending"

    // Possible values for ErrorType.
    ErrBadData     ErrorType = "bad_data"
    ErrTimeout     ErrorType = "timeout"
    ErrCanceled    ErrorType = "canceled"
    ErrExec        ErrorType = "execution"
    ErrBadResponse ErrorType = "bad_response"
    ErrServer      ErrorType = "server_error"
    ErrClient      ErrorType = "client_error"

    // Possible values for HealthStatus.
    HealthGood    HealthStatus = "up"
    HealthUnknown HealthStatus = "unknown"
    HealthBad     HealthStatus = "down"

    // Possible values for RuleType.
    RuleTypeRecording RuleType = "recording"
    RuleTypeAlerting  RuleType = "alerting"

    // Possible values for RuleHealth.
    RuleHealthGood    = "ok"
    RuleHealthUnknown = "unknown"
    RuleHealthBad     = "err"

    // Possible values for MetricType
    MetricTypeCounter        MetricType = "counter"
    MetricTypeGauge          MetricType = "gauge"
    MetricTypeHistogram      MetricType = "histogram"
    MetricTypeGaugeHistogram MetricType = "gaugehistogram"
    MetricTypeSummary        MetricType = "summary"
    MetricTypeInfo           MetricType = "info"
    MetricTypeStateset       MetricType = "stateset"
    MetricTypeUnknown        MetricType = "unknown"
)

type API interface {
    // Alerts returns a list of all active alerts.
    Alerts(ctx context.Context) (AlertsResult, error)
    // AlertManagers returns an overview of the current state of the Prometheus alert manager discovery.
    AlertManagers(ctx context.Context) (AlertManagersResult, error)
    // CleanTombstones removes the deleted data from disk and cleans up the existing tombstones.
    CleanTombstones(ctx context.Context) error
    // Config returns the current Prometheus configuration.
    Config(ctx context.Context) (ConfigResult, error)
    // DeleteSeries deletes data for a selection of series in a time range.
    DeleteSeries(ctx context.Context, matches []string, startTime time.Time, endTime time.Time) error
    // Flags returns the flag values that Prometheus was launched with.
    Flags(ctx context.Context) (FlagsResult, error)
    // LabelNames returns all the unique label names present in the block in sorted order.
    LabelNames(ctx context.Context) ([]string, api.Warnings, error)
    // LabelValues performs a query for the values of the given label.
    LabelValues(ctx context.Context, label string) (model.LabelValues, api.Warnings, error)
    // Query performs a query for the given time.
    Query(ctx context.Context, query string, ts time.Time) (model.Value, api.Warnings, error)
    // QueryRange performs a query for the given range.
    QueryRange(ctx context.Context, query string, r Range) (model.Value, api.Warnings, error)
    // Series finds series by label matchers.
    Series(ctx context.Context, matches []string, startTime time.Time, endTime time.Time) ([]model.LabelSet, api.Warnings, error)
    // Snapshot creates a snapshot of all current data into snapshots/<datetime>-<rand>
    // under the TSDB's data directory and returns the directory as response.
    Snapshot(ctx context.Context, skipHead bool) (SnapshotResult, error)
    // Rules returns a list of alerting and recording rules that are currently loaded.
    Rules(ctx context.Context) (RulesResult, error)
    // Targets returns an overview of the current state of the Prometheus target discovery.
    Targets(ctx context.Context) (TargetsResult, error)
    // TargetsMetadata returns metadata about metrics currently scraped by the target.
    TargetsMetadata(ctx context.Context, matchTarget string, metric string, limit string) ([]MetricMetadata, error)
}

type ActiveTarget struct {
    DiscoveredLabels map[string]string `json:"discoveredLabels"`
    Labels           model.LabelSet    `json:"labels"`
    ScrapeURL        string            `json:"scrapeUrl"`
    LastError        string            `json:"lastError"`
    LastScrape       time.Time         `json:"lastScrape"`
    Health           HealthStatus      `json:"health"`
}

type Alert struct {
    ActiveAt    time.Time `json:"activeAt"`
    Annotations model.LabelSet
    Labels      model.LabelSet
    State       AlertState
    Value       string
}

type AlertManager struct {
    URL string `json:"url"`
}

type AlertManagersResult struct {
    Active  []AlertManager `json:"activeAlertManagers"`
    Dropped []AlertManager `json:"droppedAlertManagers"`
}

type AlertState string

type AlertingRule struct {
    Name        string         `json:"name"`
    Query       string         `json:"query"`
    Duration    float64        `json:"duration"`
    Labels      model.LabelSet `json:"labels"`
    Annotations model.LabelSet `json:"annotations"`
    Alerts      []*Alert       `json:"alerts"`
    Health      RuleHealth     `json:"health"`
    LastError   string         `json:"lastError,omitempty"`
}

type AlertsResult struct {
    Alerts []Alert `json:"alerts"`
}

type ConfigResult struct {
    YAML string `json:"yaml"`
}

type DroppedTarget struct {
    DiscoveredLabels map[string]string `json:"discoveredLabels"`
}

type Error struct {
    Type   ErrorType
    Msg    string
    Detail string
}

type ErrorType string

type FlagsResult map[string]string

type HealthStatus string

type MetricMetadata struct {
    Target map[string]string `json:"target"`
    Metric string            `json:"metric,omitempty"`
    Type   MetricType        `json:"type"`
    Help   string            `json:"help"`
    Unit   string            `json:"unit"`
}

type MetricType string

type Range struct {
    // The boundaries of the time range.
    Start, End time.Time
    // The maximum time between two slices within the boundaries.
    Step time.Duration
}

type RecordingRule struct {
    Name      string         `json:"name"`
    Query     string         `json:"query"`
    Labels    model.LabelSet `json:"labels,omitempty"`
    Health    RuleHealth     `json:"health"`
    LastError string         `json:"lastError,omitempty"`
}

type RuleGroup struct {
    Name     string  `json:"name"`
    File     string  `json:"file"`
    Interval float64 `json:"interval"`
    Rules    Rules   `json:"rules"`
}

type RuleHealth string

type RuleType string

type Rules []interface{}

type RulesResult struct {
    Groups []RuleGroup `json:"groups"`
}

type SnapshotResult struct {
    Name string `json:"name"`
}

type TargetsResult struct {
    Active  []ActiveTarget  `json:"activeTargets"`
    Dropped []DroppedTarget `json:"droppedTargets"`
}