Torjus Håkestad
8189a108d1
Implement Phase 1.4: replaces the hardcoded banner/timeout stub with a proper shell system. Adds a Shell interface with weighted registry for shell selection, a RecordingChannel wrapper (pass-through for now, prep for Phase 2.3 replay), and a bash-like shell with fake filesystem, terminal line reader, and command handling (pwd, ls, cd, cat, whoami, hostname, id, uname, exit). Sessions now log command/output pairs to the store and record the shell name. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
85 lines
1.6 KiB
Go
85 lines
1.6 KiB
Go
package shell
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import (
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"errors"
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"fmt"
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"math/rand/v2"
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"sync"
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)
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type registryEntry struct {
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shell Shell
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weight int
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}
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// Registry holds shells with associated weights for random selection.
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type Registry struct {
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mu sync.RWMutex
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entries []registryEntry
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}
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// NewRegistry returns an empty Registry.
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func NewRegistry() *Registry {
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return &Registry{}
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}
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// Register adds a shell with the given weight. Weight must be >= 1 and
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// no duplicate names are allowed.
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func (r *Registry) Register(shell Shell, weight int) error {
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if weight < 1 {
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return fmt.Errorf("weight must be >= 1, got %d", weight)
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}
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r.mu.Lock()
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defer r.mu.Unlock()
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for _, e := range r.entries {
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if e.shell.Name() == shell.Name() {
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return fmt.Errorf("shell %q already registered", shell.Name())
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}
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}
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r.entries = append(r.entries, registryEntry{shell: shell, weight: weight})
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return nil
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}
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// Select picks a shell using weighted random selection.
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func (r *Registry) Select() (Shell, error) {
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r.mu.RLock()
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defer r.mu.RUnlock()
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if len(r.entries) == 0 {
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return nil, errors.New("no shells registered")
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}
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total := 0
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for _, e := range r.entries {
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total += e.weight
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}
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pick := rand.IntN(total)
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cumulative := 0
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for _, e := range r.entries {
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cumulative += e.weight
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if pick < cumulative {
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return e.shell, nil
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}
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}
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// Should never reach here, but return last entry as fallback.
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return r.entries[len(r.entries)-1].shell, nil
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}
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// Get returns a shell by name.
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func (r *Registry) Get(name string) (Shell, bool) {
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r.mu.RLock()
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defer r.mu.RUnlock()
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for _, e := range r.entries {
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if e.shell.Name() == name {
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return e.shell, true
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}
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}
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return nil, false
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}
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