package config

//go:generate stringer -type=Hardfork -linecomment

// Hardfork represents the application hard-fork identifier.
type Hardfork byte

// HFDefault is a default value of Hardfork enum. It's a special constant
// aimed to denote the node code enabled by default starting from the
// genesis block. HFDefault is not a hard-fork, but this constant can be used for
// convenient hard-forks comparison and to refer to the default hard-fork-less
// node behaviour.
const HFDefault Hardfork = 0 // Default

const (
	// HFAspidochelone represents hard-fork introduced in #2469 (ported from
	// https://github.com/neo-project/neo/pull/2712) and #2519 (ported from
	// https://github.com/neo-project/neo/pull/2749).
	HFAspidochelone Hardfork = 1 << iota // Aspidochelone
	// HFBasilisk represents hard-fork introduced in #3056 (ported from
	// https://github.com/neo-project/neo/pull/2881), #3080 (ported from
	// https://github.com/neo-project/neo/pull/2883) and #3085 (ported from
	// https://github.com/neo-project/neo/pull/2810).
	HFBasilisk // Basilisk
	// HFCockatrice represents hard-fork introduced in #3402 (ported from
	// https://github.com/neo-project/neo/pull/2942), #3301 (ported from
	// https://github.com/neo-project/neo/pull/2925) and #3362 (ported from
	// https://github.com/neo-project/neo/pull/3154).
	HFCockatrice // Cockatrice
	// HFDomovoi represents hard-fork introduced in #3476 (ported from
	// https://github.com/neo-project/neo/pull/3290). It makes the`node use
	// executing contract state for the contract call permissions check instead
	// of the state stored in the native Management. This change was introduced
	// in [#3473](https://github.com/nspcc-dev/neo-go/pull/3473) and ported to
	// the [reference](https://github.com/neo-project/neo/pull/3290). Also, this
	// hard-fork makes the System.Runtime.GetNotifications interop properly
	// count stack references of notification parameters which prevents users
	// from creating objects that exceed [vm.MaxStackSize] constraint. This
	// change is implemented in the
	// [reference](https://github.com/neo-project/neo/pull/3301), but NeoGo has
	// never had this bug, thus proper behaviour is preserved even before
	// HFDomovoi. It results in the fact that some T5 transactions have
	// different ApplicationLogs comparing to the C# node, but the node states
	// match. See #3485 for details.
	HFDomovoi // Domovoi
	// HFEchidna represents hard-fork introduced in #3554 (ported from
	// https://github.com/neo-project/neo/pull/3454).
	HFEchidna // Echidna
	// hfLast denotes the end of hardforks enum. Consider adding new hardforks
	// before hfLast.
	hfLast
)

// HFLatestStable is the latest known stable hardfork that is enabled by
// default. The set above can contain other hardforks and even some name
// placeholders, but they need to be enabled manually then. It can change
// between releases even if the set of known hardforks is the same.
const HFLatestStable = HFDomovoi

// HFLatestKnown is the latest known hardfork.
const HFLatestKnown = hfLast >> 1

// StableHardforks is an ordered slice of all stable hardforks (before or
// equal [HFLatestStable]).
var StableHardforks []Hardfork

// Hardforks represents the ordered slice of all possible hardforks.
var Hardforks []Hardfork

// hardforks holds a map of Hardfork string representation to its type.
var hardforks = make(map[string]Hardfork)

func init() {
	var stableIndex int

	for i := HFAspidochelone; i < hfLast; i = i << 1 {
		if i <= HFLatestStable {
			stableIndex++
		}
		Hardforks = append(Hardforks, i)
		hardforks[i.String()] = i
	}
	StableHardforks = Hardforks[:stableIndex]
}

// Cmp returns the result of hardforks comparison. It returns:
//
//	-1 if hf <  other
//	 0 if hf == other
//	+1 if hf >  other
func (hf Hardfork) Cmp(other Hardfork) int {
	switch {
	case hf == other:
		return 0
	case hf < other:
		return -1
	default:
		return 1
	}
}

// Prev returns the previous hardfork for the given one. Calling Prev for the default hardfork is a no-op.
func (hf Hardfork) Prev() Hardfork {
	if hf == HFDefault {
		panic("unexpected call to Prev for the default hardfork")
	}
	return hf >> 1
}

// IsHardforkValid denotes whether the provided string represents a valid
// Hardfork name.
func IsHardforkValid(s string) bool {
	_, ok := hardforks[s]
	return ok
}