s0rg/decompose

package graph

import (
    "fmt"
    "io"

    "github.com/s0rg/decompose/internal/node"

    "github.com/s0rg/set"
)

const orphansName = "no-orphans"

type OrphansInspector struct {
    b NamedBuilderWriter
    o set.Unordered[string]
    n []*node.Node
    e []*node.Edge
}

func NewOrphansInspector(b NamedBuilderWriter) *OrphansInspector {
    return &OrphansInspector{
        b: b,
        o: make(set.Unordered[string]),
    }
}

func (o *OrphansInspector) Name() string {
    return o.b.Name() + " " + orphansName
}

func (o *OrphansInspector) AddNode(n *node.Node) error {
    o.n = append(o.n, n)
    o.o.Add(n.ID)

    return nil
}

func (o *OrphansInspector) AddEdge(e *node.Edge) {
    o.e = append(o.e, e)
    o.o.Del(e.SrcID)
    o.o.Del(e.DstID)
}

func (o *OrphansInspector) Write(w io.Writer) (err error) {
    for _, n := range o.n {
        if o.o.Has(n.ID) {
            continue
        }

        if err = o.b.AddNode(n); err != nil {
            return fmt.Errorf("no-orphans add node: %w", err)
        }
    }

    for _, e := range o.e {
        o.b.AddEdge(e)
    }

    if err = o.b.Write(w); err != nil {
        return fmt.Errorf("no-orphans write: %w", err)
    }

    return nil
}