package metricsql

import (
	"strings"
)

var rollupFuncs = map[string]bool{
	"absent_over_time":       true,
	"aggr_over_time":         true,
	"ascent_over_time":       true,
	"avg_over_time":          true,
	"changes":                true,
	"changes_prometheus":     true,
	"count_eq_over_time":     true,
	"count_gt_over_time":     true,
	"count_le_over_time":     true,
	"count_ne_over_time":     true,
	"count_over_time":        true,
	"decreases_over_time":    true,
	"default_rollup":         true,
	"delta":                  true,
	"delta_prometheus":       true,
	"deriv":                  true,
	"deriv_fast":             true,
	"descent_over_time":      true,
	"distinct_over_time":     true,
	"duration_over_time":     true,
	"first_over_time":        true,
	"geomean_over_time":      true,
	"histogram_over_time":    true,
	"hoeffding_bound_lower":  true,
	"hoeffding_bound_upper":  true,
	"holt_winters":           true,
	"idelta":                 true,
	"ideriv":                 true,
	"increase":               true,
	"increase_prometheus":    true,
	"increase_pure":          true,
	"increases_over_time":    true,
	"integrate":              true,
	"irate":                  true,
	"lag":                    true,
	"last_over_time":         true,
	"lifetime":               true,
	"max_over_time":          true,
	"min_over_time":          true,
	"mode_over_time":         true,
	"predict_linear":         true,
	"present_over_time":      true,
	"quantile_over_time":     true,
	"quantiles_over_time":    true,
	"range_over_time":        true,
	"rate":                   true,
	"rate_over_sum":          true,
	"resets":                 true,
	"rollup":                 true,
	"rollup_candlestick":     true,
	"rollup_delta":           true,
	"rollup_deriv":           true,
	"rollup_increase":        true,
	"rollup_rate":            true,
	"rollup_scrape_interval": true,
	"scrape_interval":        true,
	"share_gt_over_time":     true,
	"share_le_over_time":     true,
	"stddev_over_time":       true,
	"stdvar_over_time":       true,
	"sum_over_time":          true,
	"sum2_over_time":         true,
	"tfirst_over_time":       true,
	// `timestamp` function must return timestamp for the last datapoint on the current window
	// in order to properly handle offset and timestamps unaligned to the current step.
	// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/415 for details.
	"timestamp":           true,
	"timestamp_with_name": true,
	"tlast_over_time":     true,
	"tmax_over_time":      true,
	"tmin_over_time":      true,
	"zscore_over_time":    true,
}

// IsRollupFunc returns whether funcName is known rollup function.
func IsRollupFunc(funcName string) bool {
	s := strings.ToLower(funcName)
	return rollupFuncs[s]
}
