refactor(10.2-01): nest framework packages under modules

- Move remaining beach packages and embedded admin assets\n- Rewrite framework, example, build, and gate paths

modules/party/registry.go

@@ -0,0 +1,220 @@
+package party
+
+import (
+	"fmt"
+	"strings"
+	"sync"
+
+	"git.golem15.com/golem15/summercms/modules/backpack"
+	"git.golem15.com/golem15/summercms/modules/pact"
+	"git.golem15.com/golem15/summercms/modules/phrasebook"
+	"git.golem15.com/golem15/summercms/modules/postcard"
+)
+
+// Plugin is the required descriptor every compiled plugin implements.
+type Plugin interface {
+	ID() string
+	Requires() []string
+	Register(app *backpack.App) error
+	Boot(app *backpack.App) error
+}
+
+var (
+	mu      sync.Mutex
+	plugins []Plugin
+)
+
+// Register appends a plugin to the process-wide registry. Plugins call this
+// from init() after a blank import; Activate selects and orders them.
+func Register(p Plugin) {
+	if p == nil {
+		return
+	}
+	mu.Lock()
+	defer mu.Unlock()
+	plugins = append(plugins, p)
+}
+
+func snapshot() []Plugin {
+	mu.Lock()
+	defer mu.Unlock()
+	out := make([]Plugin, len(plugins))
+	copy(out, plugins)
+	return out
+}
+
+// Activate resolves ids in manifest order, topologically sorts Requires(),
+// then runs every Register before any Boot.
+func Activate(app *backpack.App, ids []string) ([]Plugin, error) {
+	if app == nil {
+		return nil, fmt.Errorf("party: app is nil")
+	}
+	return activate(snapshot(), app, ids)
+}
+
+func activate(registered []Plugin, app *backpack.App, ids []string) ([]Plugin, error) {
+	byID := make(map[string]Plugin, len(registered))
+	for _, p := range registered {
+		if p == nil {
+			continue
+		}
+		id := p.ID()
+		if id == "" {
+			return nil, fmt.Errorf("party: registered plugin has empty id")
+		}
+		if _, exists := byID[id]; exists {
+			return nil, fmt.Errorf("party: duplicate plugin id %q", id)
+		}
+		byID[id] = p
+	}
+
+	seen := make(map[string]struct{}, len(ids))
+	selected := make([]Plugin, 0, len(ids))
+	index := make(map[string]int, len(ids))
+	for _, id := range ids {
+		if id == "" {
+			return nil, fmt.Errorf("party: empty plugin id in manifest")
+		}
+		if _, dup := seen[id]; dup {
+			return nil, fmt.Errorf("party: duplicate plugin id %q", id)
+		}
+		seen[id] = struct{}{}
+		p, ok := byID[id]
+		if !ok {
+			return nil, fmt.Errorf("party: plugin %q is not registered", id)
+		}
+		index[id] = len(selected)
+		selected = append(selected, p)
+	}
+
+	for _, p := range selected {
+		for _, req := range p.Requires() {
+			if _, ok := seen[req]; !ok {
+				return nil, fmt.Errorf("party: plugin %q requires %q, which is not registered", p.ID(), req)
+			}
+		}
+	}
+
+	ordered, err := topoSort(selected, index)
+	if err != nil {
+		return nil, err
+	}
+
+	orderedIDs := make([]string, len(ordered))
+	for i, p := range ordered {
+		orderedIDs[i] = p.ID()
+	}
+	app.SetPlugins(orderedIDs)
+
+	for _, p := range ordered {
+		if hc, ok := p.(pact.HasConfig); ok && app.Config != nil {
+			if err := app.Config.MergePlugin(p.ID(), hc.ConfigFS()); err != nil {
+				return nil, fmt.Errorf("party: config %s: %w", p.ID(), err)
+			}
+		}
+	}
+	for _, p := range ordered {
+		if err := p.Register(app); err != nil {
+			return nil, fmt.Errorf("party: register %s: %w", p.ID(), err)
+		}
+	}
+	if err := phrasebook.Activate(app, ordered); err != nil {
+		return nil, fmt.Errorf("party: lang: %w", err)
+	}
+	if err := postcard.Activate(app, ordered); err != nil {
+		return nil, fmt.Errorf("party: mail: %w", err)
+	}
+	for _, p := range ordered {
+		if err := postcard.BootPlugin(app, p); err != nil {
+			return nil, fmt.Errorf("party: boot %s: %w", p.ID(), err)
+		}
+		if err := p.Boot(app); err != nil {
+			return nil, fmt.Errorf("party: boot %s: %w", p.ID(), err)
+		}
+	}
+	return ordered, nil
+}
+
+func topoSort(plugins []Plugin, index map[string]int) ([]Plugin, error) {
+	byID := make(map[string]Plugin, len(plugins))
+	indeg := make(map[string]int, len(plugins))
+	dependents := make(map[string][]string, len(plugins))
+	for _, p := range plugins {
+		byID[p.ID()] = p
+		indeg[p.ID()] = 0
+	}
+	for _, p := range plugins {
+		seenReq := make(map[string]struct{})
+		for _, req := range p.Requires() {
+			if _, ok := seenReq[req]; ok {
+				continue
+			}
+			seenReq[req] = struct{}{}
+			if _, ok := byID[req]; !ok {
+				continue
+			}
+			indeg[p.ID()]++
+			dependents[req] = append(dependents[req], p.ID())
+		}
+	}
+
+	ready := make([]string, 0, len(plugins))
+	for _, p := range plugins {
+		if indeg[p.ID()] == 0 {
+			ready = append(ready, p.ID())
+		}
+	}
+
+	out := make([]Plugin, 0, len(plugins))
+	for len(ready) > 0 {
+		id := ready[0]
+		ready = ready[1:]
+		out = append(out, byID[id])
+		next := append([]string(nil), dependents[id]...)
+		sortByIndex(next, index)
+		for _, dep := range next {
+			indeg[dep]--
+			if indeg[dep] == 0 {
+				ready = insertByIndex(ready, dep, index)
+			}
+		}
+	}
+	if len(out) != len(plugins) {
+		leftover := make([]string, 0)
+		done := make(map[string]struct{}, len(out))
+		for _, p := range out {
+			done[p.ID()] = struct{}{}
+		}
+		for _, p := range plugins {
+			if _, ok := done[p.ID()]; !ok {
+				leftover = append(leftover, p.ID())
+			}
+		}
+		return nil, fmt.Errorf("party: dependency cycle involving %s", strings.Join(leftover, ", "))
+	}
+	return out, nil
+}
+
+func sortByIndex(ids []string, index map[string]int) {
+	for i := 1; i < len(ids); i++ {
+		j := i
+		for j > 0 && index[ids[j]] < index[ids[j-1]] {
+			ids[j], ids[j-1] = ids[j-1], ids[j]
+			j--
+		}
+	}
+}
+
+func insertByIndex(ready []string, id string, index map[string]int) []string {
+	at := len(ready)
+	for i, existing := range ready {
+		if index[id] < index[existing] {
+			at = i
+			break
+		}
+	}
+	ready = append(ready, "")
+	copy(ready[at+1:], ready[at:])
+	ready[at] = id
+	return ready
+}