package metadataquery
import (
"context"
"log/slog"
"time"
"github.com/modelcontextprotocol/go-sdk/mcp"
v1 "github.com/prometheus/client_golang/api/prometheus/v1"
"github.com/yshngg/prometheus-mcp-server/internal/utils"
)
const LabelNamesEndpoint = "/labels"
// URL query parameters:
// start=<rfc3339 | unix_timestamp>: Start timestamp. Optional.
// end=<rfc3339 | unix_timestamp>: End timestamp. Optional.
// match[]=<series_selector>: Repeated series selector argument that selects the series from which to read the label names. Optional.
// limit=<number>: Maximum number of returned series. Optional. 0 means disabled.
// Here is an example:
// curl 'localhost:9090/api/v1/labels'
type LabelNamesArguments struct {
Start string `json:"start,omitzero" jsonschema:"<rfc3339 | unix_timestamp>: Start timestamp. Optional."`
End string `json:"end,omitzero" jsonschema:"<rfc3339 | unix_timestamp>: End timestamp. Optional."`
Match []string `json:"match[],omitzero" jsonschema:"<series_selector>: Repeated series selector argument that selects the series from which to read the label names. Optional."`
Limit uint64 `json:"limit,omitzero" jsonschema:"<number>: Maximum number of returned series. Optional. 0 means disabled."`
}
type LabelNamesResult struct {
// TODO: Replace []string with model.LabelNames (see https://github.com/prometheus/client_golang/pull/1850).
LabelNames []string `json:"names" jsonschema:"Names is a list of string label names."`
Warnings v1.Warnings `json:"warnings,omitempty"`
}
func (q *metadataQuerier) LabelNamesHandler(ctx context.Context, request *mcp.CallToolRequest, input *LabelNamesArguments) (*mcp.CallToolResult, *LabelNamesResult, error) {
var (
start, end time.Time
err error
)
if start, err = utils.ParseTime(input.Start); err != nil {
slog.Warn("parse start time", "err", err)
}
if end, err = utils.ParseTime(input.End); err != nil {
slog.Warn("parse end time", "err", err)
}
opts := make([]v1.Option, 0)
if input.Limit != 0 {
opts = append(opts, v1.WithLimit(input.Limit))
}
result := &LabelNamesResult{}
if result.LabelNames, result.Warnings, err = q.API.LabelNames(
ctx,
input.Match,
start,
end,
opts...,
); err != nil {
return nil, nil, err
}
return nil, result, nil
}
