package kongstate

import (
	"github.com/kong/go-kong/kong"

	"github.com/kong/kubernetes-ingress-controller/v2/internal/annotations"
	configurationv1 "github.com/kong/kubernetes-ingress-controller/v2/pkg/apis/configuration/v1"
)

// Upstream is a wrapper around Upstream object in Kong.
type Upstream struct {
	kong.Upstream
	Targets []Target
	// Service this upstream is asosciated with.
	Service Service
}

func (u *Upstream) overrideHostHeader(anns map[string]string) {
	if u == nil {
		return
	}
	host := annotations.ExtractHostHeader(anns)
	if host == "" {
		return
	}
	u.HostHeader = kong.String(host)
}

// overrideByAnnotation modifies the Kong upstream based on annotations
// on the Kubernetes service.
func (u *Upstream) overrideByAnnotation(anns map[string]string) {
	if u == nil {
		return
	}
	u.overrideHostHeader(anns)
}

// overrideByKongIngress modifies the Kong upstream based on KongIngresses
// associated with the Kubernetes service.
func (u *Upstream) overrideByKongIngress(kongIngress *configurationv1.KongIngress) {
	if u == nil {
		return
	}

	if kongIngress == nil || kongIngress.Upstream == nil {
		return
	}
	k := kongIngress.Upstream
	if k.HostHeader != nil {
		u.HostHeader = kong.String(*k.HostHeader)
	}
	if k.Algorithm != nil {
		u.Algorithm = kong.String(*k.Algorithm)
	}
	if k.Slots != nil {
		u.Slots = kong.Int(*k.Slots)
	}
	if k.Healthchecks != nil {
		u.Healthchecks = k.Healthchecks
	}
	if k.HashOn != nil {
		u.HashOn = kong.String(*k.HashOn)
	}
	if k.HashFallback != nil {
		u.HashFallback = kong.String(*k.HashFallback)
	}
	if k.HashOnHeader != nil {
		u.HashOnHeader = kong.String(*k.HashOnHeader)
	}
	if k.HashFallbackHeader != nil {
		u.HashFallbackHeader = kong.String(*k.HashFallbackHeader)
	}
	if k.HashOnCookie != nil {
		u.HashOnCookie = kong.String(*k.HashOnCookie)
	}
	if k.HashOnCookiePath != nil {
		u.HashOnCookiePath = kong.String(*k.HashOnCookiePath)
	}
	// TODO https://github.com/Kong/kubernetes-ingress-controller/issues/2075
}

// override sets Upstream fields by KongIngress first, then by annotation
func (u *Upstream) override(kongIngress *configurationv1.KongIngress, anns map[string]string) {
	if u == nil {
		return
	}

	u.overrideByKongIngress(kongIngress)
	u.overrideByAnnotation(anns)
}