package catalogue

import (
	"strconv"

	"git.novox.be/novox/mesh-sdk/go/buildcpu"
)

// yieldsOf is how the runtime of its own a module is served by gives way on this node (novox/hq ADR 0553), or nil when
// it does not, and the word its steps size their threads from:
//
//   - a module holding a seat that yields (Seat.Yields, the build seats) runs at idle priority under the node's one share
//     of its processors: the node-engine's own config build-cpu-share (buildcpu.ShareSetting) as this node's layers give
//     it, its default where none does. Every yielding module of the node carries the same share, so the node-engine's
//     one yielding slice has one quota (ADR 0553 §2, §3).
//   - its word: that share (buildcpu.ShareWord), which a step divides by its own module's capacity (ADR 0553 §4).
//
// Never a refusal: a share out of range is the default, so a mistyped value bounds the builds at the default and never
// stops the node's whole composition.
func (r Resolution) yieldsOf(m Manifest, with Rendering) (map[string]any, map[string]string) {
	if !yields(m) {
		return nil, nil
	}
	engine := Manifest{Module: engineModule}
	for _, e := range r.Modules {
		if e.Module == engineModule {
			engine = e
		}
	}
	share := buildcpu.DefaultPercent
	for _, s := range Effective(engine, with.Settings[engineModule]) {
		if s.Key == buildcpu.ShareSetting {
			if n, ok := percentOf(s.Value); ok {
				share = n
			}
		}
	}
	return map[string]any{"priority": "idle", "cpu-share": share},
		map[string]string{buildcpu.ShareWord: strconv.Itoa(share)}
}

// yields is whether a module claims a seat that yields.
func yields(m Manifest) bool {
	for _, c := range m.Claims {
		if s, ok := SeatNamed(c.Name); ok && s.Yields {
			return true
		}
	}
	return false
}

// percentOf is a setting's value as a percent from 1 to 100: a number, or a string holding one.
func percentOf(v any) (int, bool) {
	var n int
	switch x := v.(type) {
	case float64:
		n = int(x)
	case int:
		n = x
	case string:
		var err error
		if n, err = strconv.Atoi(x); err != nil {
			return 0, false
		}
	default:
		return 0, false
	}
	return n, n >= 1 && n <= 100
}