From 28975b789017468dcfc8d3b972e486380ed862ea Mon Sep 17 00:00:00 2001
From: stephen mcquay <stephen@mcquay.me>
Date: Wed, 28 Feb 2018 23:20:34 -0800
Subject: [PATCH] Adds pm remote {add,rm,list}

---
 remote/remote.go | 131 ++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 125 insertions(+), 6 deletions(-)

diff --git a/remote/remote.go b/remote/remote.go
index 8ca1cd7..12064f9 100644
--- a/remote/remote.go
+++ b/remote/remote.go
@@ -1,21 +1,140 @@
 package remote
 
 import (
-	"errors"
+	"encoding/json"
+	"fmt"
 	"io"
+	"net/url"
+	"os"
+	"path/filepath"
+
+	"github.com/pkg/errors"
+	"mcquay.me/fs"
 )
 
+// DB is a slice of available URI
+type DB []url.URL
+
+const fn = "var/lib/pm/available.json"
+
 // Add appends the provided uri to the list of configured remotes.
-func Add(root string, uri []string) error {
-	return errors.New("NYI")
+func Add(root string, uris []string) error {
+	db, err := load(root)
+	if err != nil {
+		return errors.Wrap(err, "loading")
+	}
+
+	dbm := map[string]bool{}
+	for _, u := range db {
+		dbm[u.String()] = true
+	}
+
+	for _, uri := range uris {
+		pu, err := url.Parse(uri)
+		if err != nil {
+			return errors.Wrap(err, "url parse")
+		}
+
+		u := strip(*pu)
+
+		if _, ok := dbm[u.String()]; ok {
+			return fmt.Errorf("%q already in db", u.String())
+		}
+		db = append(db, u)
+	}
+
+	return save(root, db)
 }
 
 // Add removes the given uri from the list of configured remotes.
-func Remove(root string, uri []string) error {
-	return errors.New("NYI")
+func Remove(root string, uris []string) error {
+	db, err := load(root)
+	if err != nil {
+		return errors.Wrap(err, "loading")
+	}
+
+	rms := map[string]bool{}
+	for _, uri := range uris {
+		pu, err := url.Parse(uri)
+		if err != nil {
+			return errors.Wrap(err, "url parse")
+		}
+
+		u := strip(*pu)
+
+		rms[u.String()] = true
+	}
+
+	o := DB{}
+	for _, d := range db {
+		if _, ok := rms[d.String()]; !ok {
+			o = append(o, d)
+		}
+	}
+
+	if len(o) == len(db) {
+		return errors.New("found no matching remotes")
+	}
+
+	return save(root, o)
 }
 
 // List prints all configured remotes to w.
 func List(root string, w io.Writer) error {
-	return errors.New("NYI")
+	db, err := load(root)
+	if err != nil {
+		return errors.Wrap(err, "loading")
+	}
+	for _, u := range db {
+		fmt.Fprintf(w, "%s\n", u.String())
+	}
+	return nil
+}
+
+func load(root string) (DB, error) {
+	r := DB{}
+	dbn := filepath.Join(root, fn)
+
+	if !fs.Exists(dbn) {
+		return r, nil
+	}
+
+	f, err := os.Open(filepath.Join(root, fn))
+	if err != nil {
+		return r, errors.Wrap(err, "open")
+	}
+
+	if err := json.NewDecoder(f).Decode(&r); err != nil {
+		return r, errors.Wrap(err, "decoding db")
+	}
+
+	return r, nil
+}
+
+func save(root string, db DB) error {
+	f, err := os.Create(filepath.Join(root, fn))
+	if err != nil {
+		return errors.Wrap(err, "create")
+	}
+	enc := json.NewEncoder(f)
+	enc.SetIndent("", "\t")
+
+	if err := enc.Encode(&db); err != nil {
+		return errors.Wrap(err, "decoding db")
+	}
+
+	if err := f.Close(); err != nil {
+		return errors.Wrap(err, "close db")
+	}
+
+	return nil
+}
+
+// strip removes all fields we don't currently need.
+func strip(u url.URL) url.URL {
+	return url.URL{
+		Scheme: u.Scheme,
+		Host:   u.Host,
+		Path:   u.Path,
+	}
 }