asteris-llc/converge

// Copyright © 2016 Asteris, LLC
//
// 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 jsonl

import (
    "encoding/json"

    "github.com/asteris-llc/converge/graph"
    "github.com/asteris-llc/converge/graph/node"
    pp "github.com/asteris-llc/converge/prettyprinters"
)

// Node is the serializable type for graph nodes
type Node struct {
    Kind  string      `json:"kind"`
    ID    string      `json:"id"` // TODO: preserved for compat, remove in 0.4.0
    Meta  *node.Node  `json:"meta"`
    Value interface{} `json:"value"`
}

// Edge is the serializable type for graph edges
type Edge struct {
    Kind        string `json:"kind"`
    Source      string `json:"source"`
    Destination string `json:"destination"`
}

// Printer prints a graph in JSONL format
type Printer struct{}

// DrawNode prints a node in JSONL format
func (j *Printer) DrawNode(graph *graph.Graph, nodeID string) (pp.Renderable, error) {
    meta, ok := graph.Get(nodeID)
    if !ok {
        return pp.HiddenString(), nil
    }

    out, err := json.Marshal(&Node{
        Kind:  "node",
        ID:    meta.ID, // TODO: preserved for compat, remove in 0.4.0
        Meta:  meta,
        Value: meta.Value(),
    })
    return pp.VisibleString(string(out) + "\n"), err
}

// DrawEdge returns an edge in JSONL format
func (j *Printer) DrawEdge(graph *graph.Graph, srcNodeID string, dstNodeID string) (pp.Renderable, error) {
    out, err := json.Marshal(&Edge{Kind: "edge", Source: srcNodeID, Destination: dstNodeID})
    return pp.VisibleString(string(out) + "\n"), err
}