From 0d6c5d9e172ba11861a91b67e9a4d42ab4035e40 Mon Sep 17 00:00:00 2001
From: Tai Groot <tai@taigrr.com>
Date: Wed, 25 Feb 2026 20:35:45 +0000
Subject: [PATCH] feat: add per-provider mutex and Target-aware implementations

- Add snack.Locker embed for per-provider mutex serialization
- Update all providers (pacman, apk, apt, dpkg) to use []Target
  with version pinning support (pkg=version syntax)
- Add lock/unlock to all mutating operations (Install, Remove, Purge,
  Upgrade, Update)
- Add snack.TargetNames helper and formatTargets per provider
- apt: add FromRepo (-t) and Reinstall support
- dpkg: use Target.Source for .deb file paths in Install
---
 apk/apk.go             | 20 ++++++++++++++++----
 apk/apk_linux.go       | 26 ++++++++++++++++++++------
 apk/apk_other.go       |  6 +++---
 apt/apt.go             | 20 ++++++++++++++++----
 apt/apt_linux.go       | 32 ++++++++++++++++++++++++++------
 apt/apt_other.go       |  6 +++---
 dpkg/dpkg.go           | 16 ++++++++++++----
 dpkg/dpkg_linux.go     | 19 +++++++++++++------
 dpkg/dpkg_other.go     |  6 +++---
 mutex.go               | 27 +++++++++++++++++++++++++++
 pacman/pacman.go       | 20 ++++++++++++++++----
 pacman/pacman_linux.go | 36 ++++++++++++++++++++++++++++++------
 pacman/pacman_other.go |  6 +++---
 target.go              | 10 ++++++++++
 14 files changed, 198 insertions(+), 52 deletions(-)
 create mode 100644 mutex.go
 create mode 100644 target.go

diff --git a/apk/apk.go b/apk/apk.go
index 9631639..e841855 100644
--- a/apk/apk.go
+++ b/apk/apk.go
@@ -8,7 +8,9 @@ import (
 )
 
 // Apk wraps apk-tools operations.
-type Apk struct{}
+type Apk struct {
+	snack.Locker
+}
 
 // New returns a new Apk manager.
 func New() *Apk {
@@ -25,27 +27,37 @@ func (a *Apk) Name() string { return "apk" }
 func (a *Apk) Available() bool { return available() }
 
 // Install one or more packages.
-func (a *Apk) Install(ctx context.Context, pkgs []string, opts ...snack.Option) error {
+func (a *Apk) Install(ctx context.Context, pkgs []snack.Target, opts ...snack.Option) error {
+	a.Lock()
+	defer a.Unlock()
 	return install(ctx, pkgs, opts...)
 }
 
 // Remove one or more packages.
-func (a *Apk) Remove(ctx context.Context, pkgs []string, opts ...snack.Option) error {
+func (a *Apk) Remove(ctx context.Context, pkgs []snack.Target, opts ...snack.Option) error {
+	a.Lock()
+	defer a.Unlock()
 	return remove(ctx, pkgs, opts...)
 }
 
 // Purge removes packages including config files.
-func (a *Apk) Purge(ctx context.Context, pkgs []string, opts ...snack.Option) error {
+func (a *Apk) Purge(ctx context.Context, pkgs []snack.Target, opts ...snack.Option) error {
+	a.Lock()
+	defer a.Unlock()
 	return purge(ctx, pkgs, opts...)
 }
 
 // Upgrade all installed packages.
 func (a *Apk) Upgrade(ctx context.Context, opts ...snack.Option) error {
+	a.Lock()
+	defer a.Unlock()
 	return upgrade(ctx, opts...)
 }
 
 // Update refreshes the package index.
 func (a *Apk) Update(ctx context.Context) error {
+	a.Lock()
+	defer a.Unlock()
 	return update(ctx)
 }
 
diff --git a/apk/apk_linux.go b/apk/apk_linux.go
index 6fb0d4b..9f0063b 100644
--- a/apk/apk_linux.go
+++ b/apk/apk_linux.go
@@ -52,20 +52,34 @@ func run(ctx context.Context, base []string, opts ...snack.Option) (string, erro
 	return strings.TrimSpace(string(out)), nil
 }
 
-func install(ctx context.Context, pkgs []string, opts ...snack.Option) error {
-	args := append([]string{"add"}, pkgs...)
+// formatTargets converts targets to apk CLI arguments.
+// apk uses "pkg=version" for version pinning.
+func formatTargets(targets []snack.Target) []string {
+	args := make([]string, 0, len(targets))
+	for _, t := range targets {
+		if t.Version != "" {
+			args = append(args, t.Name+"="+t.Version)
+		} else {
+			args = append(args, t.Name)
+		}
+	}
+	return args
+}
+
+func install(ctx context.Context, pkgs []snack.Target, opts ...snack.Option) error {
+	args := append([]string{"add"}, formatTargets(pkgs)...)
 	_, err := run(ctx, args, opts...)
 	return err
 }
 
-func remove(ctx context.Context, pkgs []string, opts ...snack.Option) error {
-	args := append([]string{"del"}, pkgs...)
+func remove(ctx context.Context, pkgs []snack.Target, opts ...snack.Option) error {
+	args := append([]string{"del"}, snack.TargetNames(pkgs)...)
 	_, err := run(ctx, args, opts...)
 	return err
 }
 
-func purge(ctx context.Context, pkgs []string, opts ...snack.Option) error {
-	args := append([]string{"del", "--purge"}, pkgs...)
+func purge(ctx context.Context, pkgs []snack.Target, opts ...snack.Option) error {
+	args := append([]string{"del", "--purge"}, snack.TargetNames(pkgs)...)
 	_, err := run(ctx, args, opts...)
 	return err
 }
diff --git a/apk/apk_other.go b/apk/apk_other.go
index 8e7ea61..ab5155a 100644
--- a/apk/apk_other.go
+++ b/apk/apk_other.go
@@ -10,15 +10,15 @@ import (
 
 func available() bool { return false }
 
-func install(_ context.Context, _ []string, _ ...snack.Option) error {
+func install(_ context.Context, _ []snack.Target, _ ...snack.Option) error {
 	return snack.ErrUnsupportedPlatform
 }
 
-func remove(_ context.Context, _ []string, _ ...snack.Option) error {
+func remove(_ context.Context, _ []snack.Target, _ ...snack.Option) error {
 	return snack.ErrUnsupportedPlatform
 }
 
-func purge(_ context.Context, _ []string, _ ...snack.Option) error {
+func purge(_ context.Context, _ []snack.Target, _ ...snack.Option) error {
 	return snack.ErrUnsupportedPlatform
 }
 
diff --git a/apt/apt.go b/apt/apt.go
index 7bb6620..ee2867d 100644
--- a/apt/apt.go
+++ b/apt/apt.go
@@ -8,7 +8,9 @@ import (
 )
 
 // Apt implements the snack.Manager interface using apt-get and apt-cache.
-type Apt struct{}
+type Apt struct {
+	snack.Locker
+}
 
 // New returns a new Apt manager.
 func New() *Apt {
@@ -19,27 +21,37 @@ func New() *Apt {
 func (a *Apt) Name() string { return "apt" }
 
 // Install one or more packages.
-func (a *Apt) Install(ctx context.Context, pkgs []string, opts ...snack.Option) error {
+func (a *Apt) Install(ctx context.Context, pkgs []snack.Target, opts ...snack.Option) error {
+	a.Lock()
+	defer a.Unlock()
 	return install(ctx, pkgs, opts...)
 }
 
 // Remove one or more packages.
-func (a *Apt) Remove(ctx context.Context, pkgs []string, opts ...snack.Option) error {
+func (a *Apt) Remove(ctx context.Context, pkgs []snack.Target, opts ...snack.Option) error {
+	a.Lock()
+	defer a.Unlock()
 	return remove(ctx, pkgs, opts...)
 }
 
 // Purge one or more packages including config files.
-func (a *Apt) Purge(ctx context.Context, pkgs []string, opts ...snack.Option) error {
+func (a *Apt) Purge(ctx context.Context, pkgs []snack.Target, opts ...snack.Option) error {
+	a.Lock()
+	defer a.Unlock()
 	return purge(ctx, pkgs, opts...)
 }
 
 // Upgrade all installed packages.
 func (a *Apt) Upgrade(ctx context.Context, opts ...snack.Option) error {
+	a.Lock()
+	defer a.Unlock()
 	return upgrade(ctx, opts...)
 }
 
 // Update refreshes the package index.
 func (a *Apt) Update(ctx context.Context) error {
+	a.Lock()
+	defer a.Unlock()
 	return update(ctx)
 }
 
diff --git a/apt/apt_linux.go b/apt/apt_linux.go
index 35e8229..8f8a6e3 100644
--- a/apt/apt_linux.go
+++ b/apt/apt_linux.go
@@ -17,7 +17,21 @@ func available() bool {
 	return err == nil
 }
 
-func buildArgs(command string, pkgs []string, opts ...snack.Option) []string {
+// formatTargets converts targets to apt CLI arguments.
+// apt uses "pkg=version" for version pinning.
+func formatTargets(targets []snack.Target) []string {
+	args := make([]string, 0, len(targets))
+	for _, t := range targets {
+		if t.Version != "" {
+			args = append(args, t.Name+"="+t.Version)
+		} else {
+			args = append(args, t.Name)
+		}
+	}
+	return args
+}
+
+func buildArgs(command string, pkgs []snack.Target, opts ...snack.Option) []string {
 	o := snack.ApplyOptions(opts...)
 	var args []string
 	if o.Sudo {
@@ -30,11 +44,17 @@ func buildArgs(command string, pkgs []string, opts ...snack.Option) []string {
 	if o.DryRun {
 		args = append(args, "--dry-run")
 	}
-	args = append(args, pkgs...)
+	if o.FromRepo != "" {
+		args = append(args, "-t", o.FromRepo)
+	}
+	if o.Reinstall && command == "install" {
+		args = append(args, "--reinstall")
+	}
+	args = append(args, formatTargets(pkgs)...)
 	return args
 }
 
-func runAptGet(ctx context.Context, command string, pkgs []string, opts ...snack.Option) error {
+func runAptGet(ctx context.Context, command string, pkgs []snack.Target, opts ...snack.Option) error {
 	args := buildArgs(command, pkgs, opts...)
 	var cmd *exec.Cmd
 	if args[0] == "sudo" {
@@ -57,15 +77,15 @@ func runAptGet(ctx context.Context, command string, pkgs []string, opts ...snack
 	return nil
 }
 
-func install(ctx context.Context, pkgs []string, opts ...snack.Option) error {
+func install(ctx context.Context, pkgs []snack.Target, opts ...snack.Option) error {
 	return runAptGet(ctx, "install", pkgs, opts...)
 }
 
-func remove(ctx context.Context, pkgs []string, opts ...snack.Option) error {
+func remove(ctx context.Context, pkgs []snack.Target, opts ...snack.Option) error {
 	return runAptGet(ctx, "remove", pkgs, opts...)
 }
 
-func purge(ctx context.Context, pkgs []string, opts ...snack.Option) error {
+func purge(ctx context.Context, pkgs []snack.Target, opts ...snack.Option) error {
 	return runAptGet(ctx, "purge", pkgs, opts...)
 }
 
diff --git a/apt/apt_other.go b/apt/apt_other.go
index 55fa9d5..da908dd 100644
--- a/apt/apt_other.go
+++ b/apt/apt_other.go
@@ -10,15 +10,15 @@ import (
 
 func available() bool { return false }
 
-func install(_ context.Context, _ []string, _ ...snack.Option) error {
+func install(_ context.Context, _ []snack.Target, _ ...snack.Option) error {
 	return snack.ErrUnsupportedPlatform
 }
 
-func remove(_ context.Context, _ []string, _ ...snack.Option) error {
+func remove(_ context.Context, _ []snack.Target, _ ...snack.Option) error {
 	return snack.ErrUnsupportedPlatform
 }
 
-func purge(_ context.Context, _ []string, _ ...snack.Option) error {
+func purge(_ context.Context, _ []snack.Target, _ ...snack.Option) error {
 	return snack.ErrUnsupportedPlatform
 }
 
diff --git a/dpkg/dpkg.go b/dpkg/dpkg.go
index ae13949..3f6093a 100644
--- a/dpkg/dpkg.go
+++ b/dpkg/dpkg.go
@@ -8,7 +8,9 @@ import (
 )
 
 // Dpkg implements the snack.Manager interface using dpkg and dpkg-query.
-type Dpkg struct{}
+type Dpkg struct {
+	snack.Locker
+}
 
 // New returns a new Dpkg manager.
 func New() *Dpkg {
@@ -19,17 +21,23 @@ func New() *Dpkg {
 func (d *Dpkg) Name() string { return "dpkg" }
 
 // Install one or more .deb files.
-func (d *Dpkg) Install(ctx context.Context, pkgs []string, opts ...snack.Option) error {
+func (d *Dpkg) Install(ctx context.Context, pkgs []snack.Target, opts ...snack.Option) error {
+	d.Lock()
+	defer d.Unlock()
 	return install(ctx, pkgs, opts...)
 }
 
 // Remove one or more packages.
-func (d *Dpkg) Remove(ctx context.Context, pkgs []string, opts ...snack.Option) error {
+func (d *Dpkg) Remove(ctx context.Context, pkgs []snack.Target, opts ...snack.Option) error {
+	d.Lock()
+	defer d.Unlock()
 	return remove(ctx, pkgs, opts...)
 }
 
 // Purge one or more packages including config files.
-func (d *Dpkg) Purge(ctx context.Context, pkgs []string, opts ...snack.Option) error {
+func (d *Dpkg) Purge(ctx context.Context, pkgs []snack.Target, opts ...snack.Option) error {
+	d.Lock()
+	defer d.Unlock()
 	return purge(ctx, pkgs, opts...)
 }
 
diff --git a/dpkg/dpkg_linux.go b/dpkg/dpkg_linux.go
index a7cecaa..82ae927 100644
--- a/dpkg/dpkg_linux.go
+++ b/dpkg/dpkg_linux.go
@@ -17,7 +17,7 @@ func available() bool {
 	return err == nil
 }
 
-func install(ctx context.Context, pkgs []string, opts ...snack.Option) error {
+func install(ctx context.Context, pkgs []snack.Target, opts ...snack.Option) error {
 	o := snack.ApplyOptions(opts...)
 	var args []string
 	if o.Sudo {
@@ -27,7 +27,14 @@ func install(ctx context.Context, pkgs []string, opts ...snack.Option) error {
 	if o.DryRun {
 		args = append(args, "--simulate")
 	}
-	args = append(args, pkgs...)
+	// dpkg -i takes file paths; use Source if set, otherwise Name
+	for _, t := range pkgs {
+		if t.Source != "" {
+			args = append(args, t.Source)
+		} else {
+			args = append(args, t.Name)
+		}
+	}
 	cmd := exec.CommandContext(ctx, args[0], args[1:]...)
 	var stderr bytes.Buffer
 	cmd.Stderr = &stderr
@@ -41,7 +48,7 @@ func install(ctx context.Context, pkgs []string, opts ...snack.Option) error {
 	return nil
 }
 
-func remove(ctx context.Context, pkgs []string, opts ...snack.Option) error {
+func remove(ctx context.Context, pkgs []snack.Target, opts ...snack.Option) error {
 	o := snack.ApplyOptions(opts...)
 	var args []string
 	if o.Sudo {
@@ -51,7 +58,7 @@ func remove(ctx context.Context, pkgs []string, opts ...snack.Option) error {
 	if o.DryRun {
 		args = append(args, "--simulate")
 	}
-	args = append(args, pkgs...)
+	args = append(args, snack.TargetNames(pkgs)...)
 	cmd := exec.CommandContext(ctx, args[0], args[1:]...)
 	var stderr bytes.Buffer
 	cmd.Stderr = &stderr
@@ -61,7 +68,7 @@ func remove(ctx context.Context, pkgs []string, opts ...snack.Option) error {
 	return nil
 }
 
-func purge(ctx context.Context, pkgs []string, opts ...snack.Option) error {
+func purge(ctx context.Context, pkgs []snack.Target, opts ...snack.Option) error {
 	o := snack.ApplyOptions(opts...)
 	var args []string
 	if o.Sudo {
@@ -71,7 +78,7 @@ func purge(ctx context.Context, pkgs []string, opts ...snack.Option) error {
 	if o.DryRun {
 		args = append(args, "--simulate")
 	}
-	args = append(args, pkgs...)
+	args = append(args, snack.TargetNames(pkgs)...)
 	cmd := exec.CommandContext(ctx, args[0], args[1:]...)
 	var stderr bytes.Buffer
 	cmd.Stderr = &stderr
diff --git a/dpkg/dpkg_other.go b/dpkg/dpkg_other.go
index a3e54d9..0109456 100644
--- a/dpkg/dpkg_other.go
+++ b/dpkg/dpkg_other.go
@@ -10,15 +10,15 @@ import (
 
 func available() bool { return false }
 
-func install(_ context.Context, _ []string, _ ...snack.Option) error {
+func install(_ context.Context, _ []snack.Target, _ ...snack.Option) error {
 	return snack.ErrUnsupportedPlatform
 }
 
-func remove(_ context.Context, _ []string, _ ...snack.Option) error {
+func remove(_ context.Context, _ []snack.Target, _ ...snack.Option) error {
 	return snack.ErrUnsupportedPlatform
 }
 
-func purge(_ context.Context, _ []string, _ ...snack.Option) error {
+func purge(_ context.Context, _ []snack.Target, _ ...snack.Option) error {
 	return snack.ErrUnsupportedPlatform
 }
 
diff --git a/mutex.go b/mutex.go
new file mode 100644
index 0000000..67f47bc
--- /dev/null
+++ b/mutex.go
@@ -0,0 +1,27 @@
+package snack
+
+import "sync"
+
+// Locker is an embeddable type that provides per-provider mutex locking.
+// Each package manager backend should embed this in its struct to serialize
+// mutating operations (Install, Remove, Purge, Upgrade, Update).
+//
+// Read-only operations (List, Search, Info, IsInstalled, Version) generally
+// don't need the lock, but backends may choose to lock them if the underlying
+// tool doesn't support concurrent reads.
+//
+// Different providers use independent locks, so an apt Install and a snap
+// Install can run concurrently, but two apt Installs will serialize.
+type Locker struct {
+	mu sync.Mutex
+}
+
+// Lock acquires the provider lock. Call before mutating operations.
+func (l *Locker) Lock() {
+	l.mu.Lock()
+}
+
+// Unlock releases the provider lock. Defer after Lock.
+func (l *Locker) Unlock() {
+	l.mu.Unlock()
+}
diff --git a/pacman/pacman.go b/pacman/pacman.go
index cb09899..5d7e7ea 100644
--- a/pacman/pacman.go
+++ b/pacman/pacman.go
@@ -8,7 +8,9 @@ import (
 )
 
 // Pacman wraps the pacman package manager CLI.
-type Pacman struct{}
+type Pacman struct {
+	snack.Locker
+}
 
 // New returns a new Pacman manager.
 func New() *Pacman {
@@ -22,27 +24,37 @@ func (p *Pacman) Name() string { return "pacman" }
 func (p *Pacman) Available() bool { return available() }
 
 // Install one or more packages.
-func (p *Pacman) Install(ctx context.Context, pkgs []string, opts ...snack.Option) error {
+func (p *Pacman) Install(ctx context.Context, pkgs []snack.Target, opts ...snack.Option) error {
+	p.Lock()
+	defer p.Unlock()
 	return install(ctx, pkgs, opts...)
 }
 
 // Remove one or more packages.
-func (p *Pacman) Remove(ctx context.Context, pkgs []string, opts ...snack.Option) error {
+func (p *Pacman) Remove(ctx context.Context, pkgs []snack.Target, opts ...snack.Option) error {
+	p.Lock()
+	defer p.Unlock()
 	return remove(ctx, pkgs, opts...)
 }
 
 // Purge removes packages including configuration files.
-func (p *Pacman) Purge(ctx context.Context, pkgs []string, opts ...snack.Option) error {
+func (p *Pacman) Purge(ctx context.Context, pkgs []snack.Target, opts ...snack.Option) error {
+	p.Lock()
+	defer p.Unlock()
 	return purge(ctx, pkgs, opts...)
 }
 
 // Upgrade all installed packages to their latest versions.
 func (p *Pacman) Upgrade(ctx context.Context, opts ...snack.Option) error {
+	p.Lock()
+	defer p.Unlock()
 	return upgrade(ctx, opts...)
 }
 
 // Update refreshes the package database.
 func (p *Pacman) Update(ctx context.Context) error {
+	p.Lock()
+	defer p.Unlock()
 	return update(ctx)
 }
 
diff --git a/pacman/pacman_linux.go b/pacman/pacman_linux.go
index 62a9a02..2c2b0b7 100644
--- a/pacman/pacman_linux.go
+++ b/pacman/pacman_linux.go
@@ -58,23 +58,47 @@ func run(ctx context.Context, baseArgs []string, opts snack.Options) (string, er
 	return stdout.String(), nil
 }
 
-func install(ctx context.Context, pkgs []string, opts ...snack.Option) error {
+// formatTargets converts targets to pacman CLI arguments.
+// Pacman uses "pkg=version" for version pinning.
+func formatTargets(targets []snack.Target) []string {
+	args := make([]string, 0, len(targets))
+	for _, t := range targets {
+		if t.Version != "" {
+			args = append(args, t.Name+"="+t.Version)
+		} else {
+			args = append(args, t.Name)
+		}
+	}
+	return args
+}
+
+func install(ctx context.Context, pkgs []snack.Target, opts ...snack.Option) error {
 	o := snack.ApplyOptions(opts...)
-	args := append([]string{"-S", "--noconfirm"}, pkgs...)
+	base := []string{"-S", "--noconfirm"}
+	if o.Refresh {
+		base = []string{"-Sy", "--noconfirm"}
+	}
+	for _, t := range pkgs {
+		if t.FromRepo != "" || o.FromRepo != "" {
+			// Not directly supported by pacman CLI; user should configure repos
+			break
+		}
+	}
+	args := append(base, formatTargets(pkgs)...)
 	_, err := run(ctx, args, o)
 	return err
 }
 
-func remove(ctx context.Context, pkgs []string, opts ...snack.Option) error {
+func remove(ctx context.Context, pkgs []snack.Target, opts ...snack.Option) error {
 	o := snack.ApplyOptions(opts...)
-	args := append([]string{"-R", "--noconfirm"}, pkgs...)
+	args := append([]string{"-R", "--noconfirm"}, snack.TargetNames(pkgs)...)
 	_, err := run(ctx, args, o)
 	return err
 }
 
-func purge(ctx context.Context, pkgs []string, opts ...snack.Option) error {
+func purge(ctx context.Context, pkgs []snack.Target, opts ...snack.Option) error {
 	o := snack.ApplyOptions(opts...)
-	args := append([]string{"-Rns", "--noconfirm"}, pkgs...)
+	args := append([]string{"-Rns", "--noconfirm"}, snack.TargetNames(pkgs)...)
 	_, err := run(ctx, args, o)
 	return err
 }
diff --git a/pacman/pacman_other.go b/pacman/pacman_other.go
index 585d2a3..08cc776 100644
--- a/pacman/pacman_other.go
+++ b/pacman/pacman_other.go
@@ -10,15 +10,15 @@ import (
 
 func available() bool { return false }
 
-func install(_ context.Context, _ []string, _ ...snack.Option) error {
+func install(_ context.Context, _ []snack.Target, _ ...snack.Option) error {
 	return snack.ErrUnsupportedPlatform
 }
 
-func remove(_ context.Context, _ []string, _ ...snack.Option) error {
+func remove(_ context.Context, _ []snack.Target, _ ...snack.Option) error {
 	return snack.ErrUnsupportedPlatform
 }
 
-func purge(_ context.Context, _ []string, _ ...snack.Option) error {
+func purge(_ context.Context, _ []snack.Target, _ ...snack.Option) error {
 	return snack.ErrUnsupportedPlatform
 }
 
diff --git a/target.go b/target.go
new file mode 100644
index 0000000..8c23244
--- /dev/null
+++ b/target.go
@@ -0,0 +1,10 @@
+package snack
+
+// TargetNames extracts just the package names from a slice of targets.
+func TargetNames(targets []Target) []string {
+	names := make([]string, len(targets))
+	for i, t := range targets {
+		names[i] = t.Name
+	}
+	return names
+}