package system

import (
	"fmt"

	"kumoly.io/kumoly/app/util"
)

type BaseService struct{}

func (srv BaseService) GetName() string           { return "base" }
func (srv BaseService) GetDependencies() []string { return []string{""} }
func (srv BaseService) IsService() bool           { return false }
func (srv BaseService) Init() error               { return nil }
func (srv BaseService) Load() error               { return nil }
func (srv BaseService) Main() error               { return nil }
func (srv BaseService) Del()                      {}
func (srv BaseService) Health() error             { return nil }

type EasyBaseService struct {
	Name         string
	Dependencies []string
	IsServ       bool
}

func (srv EasyBaseService) GetName() string           { return srv.Name }
func (srv EasyBaseService) GetDependencies() []string { return srv.Dependencies }
func (srv EasyBaseService) IsService() bool           { return srv.IsServ }
func (srv EasyBaseService) Init() error               { return nil }
func (srv EasyBaseService) Load() error               { return nil }
func (srv EasyBaseService) Main() error               { return nil }
func (srv EasyBaseService) Del()                      {}
func (srv EasyBaseService) Health() error             { return nil }

type Inject struct {
	Name         string
	Dependencies []string
	IsServ       bool

	InitFunc   func() error
	LoadFunc   func() error
	MainFunc   func() error
	DelFunc    func()
	HealthFunc func() error
}

func (srv Inject) GetName() string           { return srv.Name }
func (srv Inject) GetDependencies() []string { return srv.Dependencies }
func (srv Inject) IsService() bool           { return srv.IsServ }
func (srv Inject) Init() error {
	if srv.InitFunc == nil {
		return nil
	}
	return srv.InitFunc()
}
func (srv Inject) Load() error {
	if srv.LoadFunc == nil {
		return nil
	}
	return srv.LoadFunc()
}
func (srv Inject) Main() error {
	if srv.MainFunc == nil {
		return nil
	}
	return srv.MainFunc()
}
func (srv Inject) Del() {
	if srv.HealthFunc == nil {
		return
	}
	srv.DelFunc()
}
func (srv Inject) Health() error {
	if srv.HealthFunc == nil {
		return nil
	}
	return srv.HealthFunc()
}

func removeNode(s []*node, i int) []*node {
	s[i] = s[len(s)-1]
	return s[:len(s)-1]
}

func removeEdge(s []string, i int) []string {
	s[i] = s[len(s)-1]
	return s[:len(s)-1]
}

type node struct {
	srv  *Service
	name string
	edge []string
}

func topo(nodes []*node) []*node {
	// check
	names := map[string]bool{}
	for _, v := range nodes {
		names[v.name] = true
	}
	for _, n := range nodes {
		for _, e := range n.edge {
			if !names[e] {
				err := fmt.Errorf("dependency not found: %v", e)
				l.Error().Err(err).Msg("")
				panic(err)
			}
		}
	}

	// start
	ret := []*node{}
	for i := 0; i <= len(nodes); i++ {
		if len(nodes) == 0 {
			break
		}
		if i == len(nodes) {
			i = 0
		}
		if nodes[i].edge == nil || len(nodes[i].edge) == 0 {
			n := nodes[i].name
			ret = append(ret, nodes[i])
			nodes = removeNode(nodes, i)
			for j := 0; j < len(nodes); j++ {
				for k := 0; k < len(nodes[j].edge); k++ {
					if nodes[j].edge[k] == n {
						nodes[j].edge = removeEdge(nodes[j].edge, k)
					}
				}
			}
			i--
		}
	}
	return ret
}

// Inject a system.Inject and uses caller as name
func (sys *System) Inject(i *Inject) {
	if i.Name == "" {
		i.Name = util.Caller(2)
	}
	sys.Append(i)
}