bridge.go

  1// Package core contains the target-agnostic code to define and run a bridge
  2package core
  3
  4import (
  5	"fmt"
  6	"reflect"
  7	"regexp"
  8	"sort"
  9	"strings"
 10	"time"
 11
 12	"github.com/MichaelMure/git-bug/cache"
 13	"github.com/MichaelMure/git-bug/repository"
 14	"github.com/pkg/errors"
 15)
 16
 17var ErrImportNotSupported = errors.New("import is not supported")
 18var ErrExportNotSupported = errors.New("export is not supported")
 19
 20const bridgeConfigKeyPrefix = "git-bug.bridge"
 21
 22var bridgeImpl map[string]reflect.Type
 23
 24// BridgeParams holds parameters to simplify the bridge configuration without
 25// having to make terminal prompts.
 26type BridgeParams struct {
 27	Owner   string
 28	Project string
 29	URL     string
 30	Token   string
 31}
 32
 33// Bridge is a wrapper around a BridgeImpl that will bind low-level
 34// implementation with utility code to provide high-level functions.
 35type Bridge struct {
 36	Name     string
 37	repo     *cache.RepoCache
 38	impl     BridgeImpl
 39	importer Importer
 40	exporter Exporter
 41	conf     Configuration
 42	initDone bool
 43}
 44
 45// Register will register a new BridgeImpl
 46func Register(impl BridgeImpl) {
 47	if bridgeImpl == nil {
 48		bridgeImpl = make(map[string]reflect.Type)
 49	}
 50	bridgeImpl[impl.Target()] = reflect.TypeOf(impl)
 51}
 52
 53// Targets return all known bridge implementation target
 54func Targets() []string {
 55	var result []string
 56
 57	for key := range bridgeImpl {
 58		result = append(result, key)
 59	}
 60
 61	sort.Strings(result)
 62
 63	return result
 64}
 65
 66// Instantiate a new Bridge for a repo, from the given target and name
 67func NewBridge(repo *cache.RepoCache, target string, name string) (*Bridge, error) {
 68	implType, ok := bridgeImpl[target]
 69	if !ok {
 70		return nil, fmt.Errorf("unknown bridge target %v", target)
 71	}
 72
 73	impl := reflect.New(implType).Elem().Interface().(BridgeImpl)
 74
 75	bridge := &Bridge{
 76		Name: name,
 77		repo: repo,
 78		impl: impl,
 79	}
 80
 81	return bridge, nil
 82}
 83
 84// Instantiate a new bridge for a repo, from the combined target and name contained
 85// in the full name
 86func NewBridgeFromFullName(repo *cache.RepoCache, fullName string) (*Bridge, error) {
 87	target, name, err := splitFullName(fullName)
 88	if err != nil {
 89		return nil, err
 90	}
 91
 92	return NewBridge(repo, target, name)
 93}
 94
 95// Attempt to retrieve a default bridge for the given repo. If zero or multiple
 96// bridge exist, it fails.
 97func DefaultBridge(repo *cache.RepoCache) (*Bridge, error) {
 98	bridges, err := ConfiguredBridges(repo)
 99	if err != nil {
100		return nil, err
101	}
102
103	if len(bridges) == 0 {
104		return nil, fmt.Errorf("no configured bridge")
105	}
106
107	if len(bridges) > 1 {
108		return nil, fmt.Errorf("multiple bridge are configured, you need to select one explicitely")
109	}
110
111	target, name, err := splitFullName(bridges[0])
112	if err != nil {
113		return nil, err
114	}
115
116	return NewBridge(repo, target, name)
117}
118
119func splitFullName(fullName string) (string, string, error) {
120	split := strings.Split(fullName, ".")
121
122	if len(split) != 2 {
123		return "", "", fmt.Errorf("bad bridge fullname: %s", fullName)
124	}
125
126	return split[0], split[1], nil
127}
128
129// ConfiguredBridges return the list of bridge that are configured for the given
130// repo
131func ConfiguredBridges(repo repository.RepoCommon) ([]string, error) {
132	configs, err := repo.ReadConfigs(bridgeConfigKeyPrefix + ".")
133	if err != nil {
134		return nil, errors.Wrap(err, "can't read configured bridges")
135	}
136
137	re, err := regexp.Compile(bridgeConfigKeyPrefix + `.([^.]+\.[^.]+)`)
138	if err != nil {
139		panic(err)
140	}
141
142	set := make(map[string]interface{})
143
144	for key := range configs {
145		res := re.FindStringSubmatch(key)
146
147		if res == nil {
148			continue
149		}
150
151		set[res[1]] = nil
152	}
153
154	result := make([]string, len(set))
155
156	i := 0
157	for key := range set {
158		result[i] = key
159		i++
160	}
161
162	return result, nil
163}
164
165// Remove a configured bridge
166func RemoveBridge(repo repository.RepoCommon, fullName string) error {
167	re, err := regexp.Compile(`^[^.]+\.[^.]+$`)
168	if err != nil {
169		panic(err)
170	}
171
172	if !re.MatchString(fullName) {
173		return fmt.Errorf("bad bridge fullname: %s", fullName)
174	}
175
176	keyPrefix := fmt.Sprintf("git-bug.bridge.%s", fullName)
177	return repo.RmConfigs(keyPrefix)
178}
179
180// Configure run the target specific configuration process
181func (b *Bridge) Configure(params BridgeParams) error {
182	conf, err := b.impl.Configure(b.repo, params)
183	if err != nil {
184		return err
185	}
186
187	b.conf = conf
188
189	return b.storeConfig(conf)
190}
191
192func (b *Bridge) storeConfig(conf Configuration) error {
193	for key, val := range conf {
194		storeKey := fmt.Sprintf("git-bug.bridge.%s.%s.%s", b.impl.Target(), b.Name, key)
195
196		err := b.repo.StoreConfig(storeKey, val)
197		if err != nil {
198			return errors.Wrap(err, "error while storing bridge configuration")
199		}
200	}
201
202	return nil
203}
204
205func (b *Bridge) ensureConfig() error {
206	if b.conf == nil {
207		conf, err := b.loadConfig()
208		if err != nil {
209			return err
210		}
211		b.conf = conf
212	}
213
214	return nil
215}
216
217func (b *Bridge) loadConfig() (Configuration, error) {
218	keyPrefix := fmt.Sprintf("git-bug.bridge.%s.%s.", b.impl.Target(), b.Name)
219
220	pairs, err := b.repo.ReadConfigs(keyPrefix)
221	if err != nil {
222		return nil, errors.Wrap(err, "error while reading bridge configuration")
223	}
224
225	result := make(Configuration, len(pairs))
226	for key, value := range pairs {
227		key := strings.TrimPrefix(key, keyPrefix)
228		result[key] = value
229	}
230
231	err = b.impl.ValidateConfig(result)
232	if err != nil {
233		return nil, errors.Wrap(err, "invalid configuration")
234	}
235
236	return result, nil
237}
238
239func (b *Bridge) getImporter() Importer {
240	if b.importer == nil {
241		b.importer = b.impl.NewImporter()
242	}
243
244	return b.importer
245}
246
247func (b *Bridge) getExporter() Exporter {
248	if b.exporter == nil {
249		b.exporter = b.impl.NewExporter()
250	}
251
252	return b.exporter
253}
254
255func (b *Bridge) ensureInit() error {
256	if b.initDone {
257		return nil
258	}
259
260	importer := b.getImporter()
261	if importer != nil {
262		err := importer.Init(b.conf)
263		if err != nil {
264			return err
265		}
266	}
267
268	exporter := b.getExporter()
269	if exporter != nil {
270		err := exporter.Init(b.conf)
271		if err != nil {
272			return err
273		}
274	}
275
276	b.initDone = true
277
278	return nil
279}
280
281func (b *Bridge) ImportAll(since time.Time) error {
282	importer := b.getImporter()
283	if importer == nil {
284		return ErrImportNotSupported
285	}
286
287	err := b.ensureConfig()
288	if err != nil {
289		return err
290	}
291
292	err = b.ensureInit()
293	if err != nil {
294		return err
295	}
296
297	return importer.ImportAll(b.repo, since)
298}
299
300func (b *Bridge) ExportAll(since time.Time) error {
301	exporter := b.getExporter()
302	if exporter == nil {
303		return ErrExportNotSupported
304	}
305
306	err := b.ensureConfig()
307	if err != nil {
308		return err
309	}
310
311	err = b.ensureInit()
312	if err != nil {
313		return err
314	}
315
316	return exporter.ExportAll(b.repo, since)
317}