package expressionquery
import (
"context"
"log/slog"
"time"
"github.com/modelcontextprotocol/go-sdk/mcp"
v1 "github.com/prometheus/client_golang/api/prometheus/v1"
"github.com/prometheus/common/model"
"github.com/yshngg/prometheus-mcp-server/internal/utils"
)
const InstantQueryEndpoint = "/query"
// URL query parameters:
// query=<string>: Prometheus expression query string.
// time=<rfc3339 | unix_timestamp>: Evaluation timestamp. Optional.
// timeout=<duration>: Evaluation timeout. Optional. Defaults to and is capped by the value of the -query.timeout flag.
// limit=<number>: Maximum number of returned series. Doesn’t affect scalars or strings but truncates the number of series for matrices and vectors. Optional. 0 means disabled.
// The following example evaluates the expression up at the time 2015-07-01T20:10:51.781Z:
// curl 'http://localhost:9090/api/v1/query?query=up&time=2015-07-01T20:10:51.781Z'
type InstantQueryArguments struct {
Query string `json:"query" jsonschema:"<string>: Prometheus expression query string."`
Time string `json:"time,omitzero" jsonschema:"<rfc3339 | unix_timestamp>: Evaluation timestamp. Optional."`
Timeout time.Duration `json:"timeout,omitzero" jsonschema:"<duration>: Evaluation timeout. Optional. Defaults to and is capped by the value of the -query.timeout flag."`
Limit uint64 `json:"limit,omitzero" jsonschema:"<number>: Maximum number of returned series. Doesn't affect scalars or strings but truncates the number of series for matrices and vectors. Optional. 0 means disabled."`
}
type InstantQueryResult struct {
Value model.Value `json:"value" jsonschema:"<value> refers to the query result data, which has varying formats depending on the resultType. See the [expression query result formats](https://prometheus.io/docs/prometheus/latest/querying/api/#expression-query-result-formats)."`
Warnings v1.Warnings `json:"warnings,omitempty"`
}
func (q *expressionQuerier) InstantQueryHandler(ctx context.Context, request *mcp.CallToolRequest, input *InstantQueryArguments) (*mcp.CallToolResult, *InstantQueryResult, error) {
var (
ts time.Time
err error
)
if ts, err = utils.ParseTime(input.Time); err != nil {
slog.Warn("parse time", "err", err)
}
opts := make([]v1.Option, 0)
if input.Timeout != 0 {
opts = append(opts, v1.WithTimeout(input.Timeout))
}
if input.Limit != 0 {
opts = append(opts, v1.WithLimit(input.Limit))
}
result := &InstantQueryResult{}
if result.Value, result.Warnings, err = q.API.Query(
ctx,
input.Query,
ts,
opts...,
); err != nil {
return nil, nil, err
}
return nil, result, nil
}
