// Copyright 2019 Yunion
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package guest

import (
	"context"

	"yunion.io/x/onecloud/pkg/apis"
	"yunion.io/x/onecloud/pkg/apis/compute"
	"yunion.io/x/onecloud/pkg/scheduler/algorithm/predicates"
	"yunion.io/x/onecloud/pkg/scheduler/core"
)

// CPUPredicate check the current resources of the CPU is available,
// it returns the maximum available capacity.
type CPUPredicate struct {
	predicates.BasePredicate
}

func (f *CPUPredicate) Name() string {
	return "host_cpu"
}

func (f *CPUPredicate) Clone() core.FitPredicate {
	return &CPUPredicate{}
}

func (f *CPUPredicate) PreExecute(ctx context.Context, u *core.Unit, cs []core.Candidater) (bool, error) {
	driver := u.GetHypervisorDriver()
	if driver != nil && !driver.DoScheduleCPUFilter() {
		return false, nil
	}

	data := u.SchedData()

	if data.Ncpu <= 0 {
		return false, nil
	}

	return true, nil
}

func (f *CPUPredicate) Execute(ctx context.Context, u *core.Unit, c core.Candidater) (bool, []core.PredicateFailureReason, error) {
	h := predicates.NewPredicateHelper(f, u, c)
	d := u.SchedData()

	useRsvd := h.UseReserved()
	getter := c.Getter()

	archMatch := true
	isArmHost := getter.IsArmHost()
	isRiscvHost := getter.IsRISCVHost()
	if d.Hypervisor != compute.HYPERVISOR_POD {
		if apis.IsARM(d.OsArch) {
			// process arm64 host
			if !isArmHost {
				archMatch = false
			}
		} else if apis.IsRISCV(d.OsArch) {
			if !isRiscvHost {
				archMatch = false
			}
		} else {
			// process x86_64 host
			if isArmHost || isRiscvHost {
				archMatch = false
			}
		}
	}

	if !archMatch {
		h.Exclude2(predicates.ErrHostCpuArchitectureNotMatch, getter.CPUArch(), d.OsArch)
		return h.GetResult()
	}

	reqCPUCount := int64(d.Ncpu + d.ExtraCpuCount)
	if getter.KvmCapMaxVcpuCount() > 0 && reqCPUCount > getter.KvmCapMaxVcpuCount() {
		h.Exclude2(predicates.ErrHostKvmVcpuMaxNotEnough, getter.KvmCapMaxVcpuCount(), reqCPUCount)
		return h.GetResult()
	}

	freeCPUCount := getter.FreeCPUCount(useRsvd)
	if freeCPUCount < reqCPUCount {
		totalCPUCount := getter.TotalCPUCount(useRsvd)
		h.AppendInsufficientResourceError(reqCPUCount, totalCPUCount, freeCPUCount)
	}

	h.SetCapacity(freeCPUCount / reqCPUCount)
	return h.GetResult()
}