package execenv

import (
	"os"
	"path/filepath"
	"strings"
	"testing"

	"gopkg.in/yaml.v3"
)

// hermesExternalDirs parses skills.external_dirs out of a derived config.yaml.
func hermesExternalDirs(t *testing.T, configPath string) []string {
	t.Helper()
	data, err := os.ReadFile(configPath)
	if err != nil {
		t.Fatalf("read derived config: %v", err)
	}
	var parsed struct {
		Skills struct {
			ExternalDirs []string `yaml:"external_dirs"`
		} `yaml:"skills"`
	}
	if err := yaml.Unmarshal(data, &parsed); err != nil {
		t.Fatalf("parse derived config: %v\n%s", err, data)
	}
	return parsed.Skills.ExternalDirs
}

// hermesMemoryProvider returns the memory.provider value in a derived config,
// and whether the key is present.
func hermesMemoryProvider(t *testing.T, configPath string) (string, bool) {
	t.Helper()
	data, err := os.ReadFile(configPath)
	if err != nil {
		t.Fatalf("read derived config: %v", err)
	}
	var parsed struct {
		Memory struct {
			Provider *string `yaml:"provider"`
		} `yaml:"memory"`
	}
	if err := yaml.Unmarshal(data, &parsed); err != nil {
		t.Fatalf("parse derived config: %v", err)
	}
	if parsed.Memory.Provider == nil {
		return "", false
	}
	return *parsed.Memory.Provider, true
}

// TestPrepareHermesHomeOverlay verifies the compatibility overlay: shared state
// is mirrored via symlink, the derived config references the user's real skills
// as an external root, and only the bound skill lands in the task-local skills/
// dir (the user's global skills are referenced, not copied).
func TestPrepareHermesHomeOverlay(t *testing.T) {
	t.Parallel()
	sharedHome := t.TempDir()
	mustWrite(t, filepath.Join(sharedHome, "auth.json"), `{"token":"secret"}`)
	mustWrite(t, filepath.Join(sharedHome, ".env"), "API_KEY=abc")
	mustWrite(t, filepath.Join(sharedHome, "config.yaml"), "model: hermes-4\n")
	mustWrite(t, filepath.Join(sharedHome, "plugins", "custom-provider", "plugin.py"), "# provider plugin")
	mustWrite(t, filepath.Join(sharedHome, "oauth_state.json"), `{"nous":"tok"}`)
	mustWrite(t, filepath.Join(sharedHome, "skills", "personal-notes", "SKILL.md"), "My personal notes skill.")

	hermesHome := filepath.Join(t.TempDir(), "hermes-home")
	skills := []SkillContextForEnv{{Name: "Review Helper", Content: "Help review code."}}
	if err := prepareHermesHome(hermesHome, sharedHome, false, skills, nil, testLogger()); err != nil {
		t.Fatalf("prepareHermesHome failed: %v", err)
	}

	for _, name := range []string{"auth.json", "plugins", "oauth_state.json"} {
		fi, err := os.Lstat(filepath.Join(hermesHome, name))
		if err != nil {
			t.Fatalf("%s not mirrored into overlay: %v", name, err)
		}
		if fi.Mode()&os.ModeSymlink == 0 {
			t.Errorf("%s should be a symlink into the shared home", name)
		}
	}

	// .env is overlay-owned/derived (not symlinked): it preserves the source's
	// credentials but pins HERMES_HOME to the overlay so Hermes' override=True
	// dotenv load can't relocate the home past it.
	envPath := filepath.Join(hermesHome, ".env")
	if fi, err := os.Lstat(envPath); err != nil {
		t.Fatalf(".env missing from overlay: %v", err)
	} else if fi.Mode()&os.ModeSymlink != 0 {
		t.Error(".env should be a derived copy, not a symlink into the shared home")
	}
	if data, _ := os.ReadFile(envPath); !strings.Contains(string(data), "API_KEY=abc") {
		t.Error("derived .env dropped the source credentials")
	} else if !strings.Contains(string(data), "HERMES_HOME='"+hermesHome+"'") {
		t.Errorf("derived .env must pin HERMES_HOME to the overlay, got:\n%s", data)
	}

	cfgPath := filepath.Join(hermesHome, "config.yaml")
	if fi, err := os.Lstat(cfgPath); err != nil {
		t.Fatalf("config.yaml missing: %v", err)
	} else if fi.Mode()&os.ModeSymlink != 0 {
		t.Error("config.yaml should be a derived copy, not a symlink")
	}
	if data, _ := os.ReadFile(cfgPath); !strings.Contains(string(data), "hermes-4") {
		t.Error("derived config dropped the user's model setting")
	}
	wantExternal := filepath.Join(sharedHome, "skills")
	if got := hermesExternalDirs(t, cfgPath); len(got) != 1 || got[0] != wantExternal {
		t.Errorf("external_dirs = %v, want [%s]", got, wantExternal)
	}

	if body, err := os.ReadFile(filepath.Join(hermesHome, "skills", "review-helper", "SKILL.md")); err != nil {
		t.Fatalf("bound skill not written: %v", err)
	} else if !strings.Contains(string(body), "Help review code.") {
		t.Error("bound SKILL.md missing content")
	}
	if _, err := os.Stat(filepath.Join(hermesHome, "skills", "personal-notes")); !os.IsNotExist(err) {
		t.Error("user global skill should be referenced via external_dirs, not copied into the task-local skills/")
	}
}

// TestHermesDisablesExternalMemoryProvider is the regression for the shared
// memory-backend blocker: a host-configured memory.provider must be neutralized
// in the derived config so managed tasks don't share an external memory bank.
func TestHermesDisablesExternalMemoryProvider(t *testing.T) {
	t.Parallel()
	sharedHome := t.TempDir()
	mustWrite(t, filepath.Join(sharedHome, "config.yaml"),
		"memory:\n  provider: supermemory\n  memory_enabled: true\n")

	hermesHome := filepath.Join(t.TempDir(), "hermes-home")
	skills := []SkillContextForEnv{{Name: "Review Helper", Content: "x"}}
	if err := prepareHermesHome(hermesHome, sharedHome, false, skills, nil, testLogger()); err != nil {
		t.Fatalf("prepareHermesHome failed: %v", err)
	}

	got, ok := hermesMemoryProvider(t, filepath.Join(hermesHome, "config.yaml"))
	if !ok {
		t.Fatal("memory.provider should be present and explicitly disabled")
	}
	if got != "" {
		t.Errorf("memory.provider = %q, want \"\" (external backend disabled)", got)
	}
	if data, _ := os.ReadFile(filepath.Join(hermesHome, "config.yaml")); !strings.Contains(string(data), "memory_enabled: true") {
		t.Error("built-in memory settings should be preserved")
	}
}

// TestHermesDerivedConfigRebasesRelativeExternalDirs is the regression for the
// silent-repoint bug: relative external_dirs must be rewritten to absolute paths
// anchored at the shared home, absolute entries left intact, and the real skills
// dir appended.
func TestHermesDerivedConfigRebasesRelativeExternalDirs(t *testing.T) {
	t.Parallel()
	sharedHome := t.TempDir()
	mustWrite(t, filepath.Join(sharedHome, "config.yaml"),
		"model: hermes-4\nskills:\n  external_dirs:\n    - team-skills\n    - /opt/shared/skills\n")

	hermesHome := filepath.Join(t.TempDir(), "hermes-home")
	skills := []SkillContextForEnv{{Name: "Review Helper", Content: "x"}}
	if err := prepareHermesHome(hermesHome, sharedHome, false, skills, nil, testLogger()); err != nil {
		t.Fatalf("prepareHermesHome failed: %v", err)
	}

	got := hermesExternalDirs(t, filepath.Join(hermesHome, "config.yaml"))
	want := []string{
		filepath.Join(sharedHome, "team-skills"),
		"/opt/shared/skills",
		filepath.Join(sharedHome, "skills"),
	}
	if strings.Join(got, "\n") != strings.Join(want, "\n") {
		t.Errorf("external_dirs =\n%v\nwant\n%v", got, want)
	}
}

// TestHermesExternalDirsExpandsSanitizedEnv verifies a ${VAR} present in the
// sanitized effective env expands, while an UNKNOWN var is preserved verbatim
// (Hermes/Python expandvars semantics) instead of collapsing to empty and being
// silently rewritten to an absolute path.
func TestHermesExternalDirsExpandsSanitizedEnv(t *testing.T) {
	t.Parallel()
	sharedHome := t.TempDir()
	mustWrite(t, filepath.Join(sharedHome, "config.yaml"),
		"skills:\n  external_dirs:\n    - ${TEAM_SKILLS}/reviews\n    - ${MYSTERY_VAR}/x\n")

	hermesHome := filepath.Join(t.TempDir(), "hermes-home")
	env := map[string]string{"TEAM_SKILLS": "/srv/team"} // MYSTERY_VAR set nowhere
	skills := []SkillContextForEnv{{Name: "Review Helper", Content: "x"}}
	if err := prepareHermesHome(hermesHome, sharedHome, false, skills, env, testLogger()); err != nil {
		t.Fatalf("prepareHermesHome failed: %v", err)
	}

	got := hermesExternalDirs(t, filepath.Join(hermesHome, "config.yaml"))
	want := []string{
		"/srv/team/reviews", // known var expanded
		"${MYSTERY_VAR}/x",  // unknown var preserved verbatim, NOT absolutized
		filepath.Join(sharedHome, "skills"),
	}
	if strings.Join(got, "\n") != strings.Join(want, "\n") {
		t.Errorf("external_dirs =\n%v\nwant\n%v", got, want)
	}
}

// TestHermesBoundSkillKeepsNaturalSlug asserts a bound skill sharing a name with
// a user global skill keeps its natural slug (so Hermes resolves the bound
// version, home skills first) and leaves the user's shared copy untouched.
func TestHermesBoundSkillKeepsNaturalSlug(t *testing.T) {
	t.Parallel()
	sharedHome := t.TempDir()
	userSkill := filepath.Join(sharedHome, "skills", "review-helper", "SKILL.md")
	mustWrite(t, userSkill, "USER VERSION")

	hermesHome := filepath.Join(t.TempDir(), "hermes-home")
	skills := []SkillContextForEnv{{Name: "Review Helper", Content: "WORKSPACE VERSION"}}
	if err := prepareHermesHome(hermesHome, sharedHome, false, skills, nil, testLogger()); err != nil {
		t.Fatalf("prepareHermesHome failed: %v", err)
	}

	body, err := os.ReadFile(filepath.Join(hermesHome, "skills", "review-helper", "SKILL.md"))
	if err != nil {
		t.Fatalf("read bound skill: %v", err)
	}
	if strings.Contains(string(body), "USER VERSION") || !strings.Contains(string(body), "WORKSPACE VERSION") {
		t.Errorf("bound skill should keep natural slug with its own content, got: %q", body)
	}
	if data, _ := os.ReadFile(userSkill); string(data) != "USER VERSION" {
		t.Errorf("user's shared skill was modified: %q", data)
	}
}

// TestHermesOverlayIsolatesMemories asserts the host memory dir isn't reachable
// from the task, task writes don't touch the host, and the task-local dir
// survives reuse.
func TestHermesOverlayIsolatesMemories(t *testing.T) {
	t.Parallel()
	sharedHome := t.TempDir()
	mustWrite(t, filepath.Join(sharedHome, "config.yaml"), "model: hermes-4\n")
	mustWrite(t, filepath.Join(sharedHome, "memories", "MEMORY.md"), "HOST MEMORY — must not leak")

	hermesHome := filepath.Join(t.TempDir(), "hermes-home")
	skills := []SkillContextForEnv{{Name: "Review Helper", Content: "x"}}
	if err := prepareHermesHome(hermesHome, sharedHome, false, skills, nil, testLogger()); err != nil {
		t.Fatalf("prepareHermesHome failed: %v", err)
	}

	memDir := filepath.Join(hermesHome, "memories")
	if fi, err := os.Lstat(memDir); err != nil {
		t.Fatalf("task memories dir missing: %v", err)
	} else if fi.Mode()&os.ModeSymlink != 0 {
		t.Fatal("task memories/ must be a real dir, not a symlink into the host home")
	}
	if _, err := os.Stat(filepath.Join(memDir, "MEMORY.md")); !os.IsNotExist(err) {
		t.Error("host MEMORY.md must not be visible in the task")
	}

	mustWrite(t, filepath.Join(memDir, "MEMORY.md"), "TASK MEMORY")
	if data, _ := os.ReadFile(filepath.Join(sharedHome, "memories", "MEMORY.md")); string(data) != "HOST MEMORY — must not leak" {
		t.Errorf("host memory was modified through the overlay: %q", data)
	}
	if err := prepareHermesHome(hermesHome, sharedHome, false, skills, nil, testLogger()); err != nil {
		t.Fatalf("prepareHermesHome (reuse) failed: %v", err)
	}
	if data, _ := os.ReadFile(filepath.Join(memDir, "MEMORY.md")); string(data) != "TASK MEMORY" {
		t.Errorf("reuse should preserve task-local memory, got: %q", data)
	}
}

// TestHermesOverlayPermissions asserts the task home is 0700 and the derived
// config (which can hold inline api_key secrets) is 0600.
func TestHermesOverlayPermissions(t *testing.T) {
	t.Parallel()
	sharedHome := t.TempDir()
	mustWrite(t, filepath.Join(sharedHome, "config.yaml"), "model: hermes-4\napi_key: sk-secret\n")

	hermesHome := filepath.Join(t.TempDir(), "hermes-home")
	skills := []SkillContextForEnv{{Name: "Review Helper", Content: "x"}}
	if err := prepareHermesHome(hermesHome, sharedHome, false, skills, nil, testLogger()); err != nil {
		t.Fatalf("prepareHermesHome failed: %v", err)
	}

	if fi, err := os.Stat(hermesHome); err != nil {
		t.Fatalf("stat home: %v", err)
	} else if fi.Mode().Perm() != 0o700 {
		t.Errorf("task home perms = %o, want 0700", fi.Mode().Perm())
	}
	if fi, err := os.Stat(filepath.Join(hermesHome, "config.yaml")); err != nil {
		t.Fatalf("stat config: %v", err)
	} else if fi.Mode().Perm() != 0o600 {
		t.Errorf("derived config perms = %o, want 0600", fi.Mode().Perm())
	}
}

// TestHermesOverlayReconcilesDeletedSharedEntry asserts a top-level entry
// removed from the shared home is dropped from the overlay on rebuild.
func TestHermesOverlayReconcilesDeletedSharedEntry(t *testing.T) {
	t.Parallel()
	sharedHome := t.TempDir()
	mustWrite(t, filepath.Join(sharedHome, "config.yaml"), "model: hermes-4\n")
	mustWrite(t, filepath.Join(sharedHome, "plugins", "p", "plugin.py"), "# plugin")

	hermesHome := filepath.Join(t.TempDir(), "hermes-home")
	skills := []SkillContextForEnv{{Name: "Review Helper", Content: "x"}}
	if err := prepareHermesHome(hermesHome, sharedHome, false, skills, nil, testLogger()); err != nil {
		t.Fatalf("prepareHermesHome failed: %v", err)
	}
	if _, err := os.Lstat(filepath.Join(hermesHome, "plugins")); err != nil {
		t.Fatalf("plugins not mirrored: %v", err)
	}
	if err := os.RemoveAll(filepath.Join(sharedHome, "plugins")); err != nil {
		t.Fatalf("remove shared plugins: %v", err)
	}
	if err := prepareHermesHome(hermesHome, sharedHome, false, skills, nil, testLogger()); err != nil {
		t.Fatalf("prepareHermesHome (rebuild) failed: %v", err)
	}
	if _, err := os.Lstat(filepath.Join(hermesHome, "plugins")); !os.IsNotExist(err) {
		t.Error("stale mirrored plugins should be reconciled away after deletion in the shared home")
	}
}

// TestPrepareHermesHomeFailsClosed asserts prepareHermesHome returns an error
// when required overlay state can't be built (here an unreadable shared config).
func TestPrepareHermesHomeFailsClosed(t *testing.T) {
	t.Parallel()
	sharedHome := t.TempDir()
	if err := os.MkdirAll(filepath.Join(sharedHome, "config.yaml"), 0o755); err != nil {
		t.Fatalf("mkdir config.yaml dir: %v", err)
	}
	hermesHome := filepath.Join(t.TempDir(), "hermes-home")
	skills := []SkillContextForEnv{{Name: "Review Helper", Content: "x"}}
	if err := prepareHermesHome(hermesHome, sharedHome, false, skills, nil, testLogger()); err == nil {
		t.Fatal("expected prepareHermesHome to fail closed on an unreadable shared config")
	}
}

// TestResolveHermesProfile exercises the one resolver contract against the
// behaviors the review requires it to match Hermes on: sticky selection, an
// already-profile-scoped home, `-p default`/`-p <sibling>` re-rooting, and native
// failure on reserved/invalid/empty names. Temp dirs stand in for custom Hermes
// roots (they are never under the host's platform-default home, so root
// derivation takes the deterministic custom/profile branch).
func TestResolveHermesProfile(t *testing.T) {
	t.Parallel()

	t.Run("no profile resolves to the base home", func(t *testing.T) {
		t.Parallel()
		base := t.TempDir()
		res := ResolveHermesProfile(base, "", false, false)
		if res.Err != nil || res.SourceHome != base || res.MustExist {
			t.Fatalf("got %+v, want SourceHome=%q MustExist=false Err=nil", res, base)
		}
	})

	// The review's blocker 1: a sticky active_profile must be SELECTED as the
	// overlay source, not merely blocked from bypassing.
	t.Run("root + sticky named profile selects the profile as source", func(t *testing.T) {
		t.Parallel()
		root := t.TempDir()
		mustWrite(t, filepath.Join(root, "active_profile"), "coder\n")
		res := ResolveHermesProfile(root, "", false, false)
		want := filepath.Join(root, "profiles", "coder")
		if res.Err != nil || res.SourceHome != want || !res.MustExist {
			t.Fatalf("sticky: got %+v, want SourceHome=%q MustExist=true", res, want)
		}
	})

	t.Run("sticky default is ignored", func(t *testing.T) {
		t.Parallel()
		root := t.TempDir()
		mustWrite(t, filepath.Join(root, "active_profile"), "default\n")
		res := ResolveHermesProfile(root, "", false, false)
		if res.Err != nil || res.SourceHome != root || res.MustExist {
			t.Fatalf("sticky default: got %+v, want SourceHome=%q MustExist=false", res, root)
		}
	})

	t.Run("already-profile-scoped home with no flag is trusted", func(t *testing.T) {
		t.Parallel()
		root := t.TempDir()
		scoped := filepath.Join(root, "profiles", "coder")
		// A sticky at the root must NOT override an explicit profile-scoped home.
		mustWrite(t, filepath.Join(root, "active_profile"), "research\n")
		res := ResolveHermesProfile(scoped, "", false, false)
		if res.Err != nil || res.SourceHome != scoped || !res.MustExist {
			t.Fatalf("profile-scoped: got %+v, want SourceHome=%q MustExist=true", res, scoped)
		}
	})

	t.Run("-p default from a profile-scoped home re-roots to the root", func(t *testing.T) {
		t.Parallel()
		root := t.TempDir()
		scoped := filepath.Join(root, "profiles", "coder")
		res := ResolveHermesProfile(scoped, "default", true, false)
		if res.Err != nil || res.SourceHome != root || res.MustExist {
			t.Fatalf("-p default: got %+v, want SourceHome=%q MustExist=false", res, root)
		}
	})

	t.Run("-p sibling from a profile-scoped home is a sibling, not nested", func(t *testing.T) {
		t.Parallel()
		root := t.TempDir()
		scoped := filepath.Join(root, "profiles", "coder")
		res := ResolveHermesProfile(scoped, "research", true, false)
		want := filepath.Join(root, "profiles", "research")
		if res.Err != nil || res.SourceHome != want || !res.MustExist {
			t.Fatalf("-p sibling: got %+v, want SourceHome=%q MustExist=true", res, want)
		}
	})

	t.Run("explicit named profile resolves under the root", func(t *testing.T) {
		t.Parallel()
		root := t.TempDir()
		res := ResolveHermesProfile(root, "research", true, false)
		want := filepath.Join(root, "profiles", "research")
		if res.Err != nil || res.SourceHome != want || !res.MustExist {
			t.Fatalf("named: got %+v, want SourceHome=%q MustExist=true", res, want)
		}
	})

	t.Run("reserved names fail closed", func(t *testing.T) {
		t.Parallel()
		root := t.TempDir()
		for _, name := range []string{"hermes", "test", "tmp", "root", "sudo"} {
			if res := ResolveHermesProfile(root, name, true, false); res.Err == nil {
				t.Errorf("reserved %q: expected Err, got SourceHome=%q", name, res.SourceHome)
			}
		}
	})

	t.Run("empty inline value fails closed", func(t *testing.T) {
		t.Parallel()
		root := t.TempDir()
		if res := ResolveHermesProfile(root, "", true, true); res.Err == nil {
			t.Error("empty inline --profile= must fail closed, not fall back to default")
		}
	})

	t.Run("empty inputs resolve to a platform default", func(t *testing.T) {
		t.Parallel()
		if res := ResolveHermesProfile("", "", false, false); res.SourceHome == "" {
			t.Error("empty inputs should resolve to a platform default, not empty")
		}
	})
}

// TestHermesExternalDirsExpandsAgainstSelectedProfileHome is the review's blocker
// 3: a ${HERMES_HOME} in a selected profile's skills.external_dirs must expand
// against the SELECTED profile home (what native Hermes sees after applying the
// profile override before loading config.yaml), not the pre-resolution/root home
// or the task overlay. The daemon sets the effective env's HERMES_HOME to the
// resolved source home for exactly this reason.
func TestHermesExternalDirsExpandsAgainstSelectedProfileHome(t *testing.T) {
	t.Parallel()
	profileHome := t.TempDir() // stands in for <root>/profiles/coder
	mustWrite(t, filepath.Join(profileHome, "config.yaml"),
		"skills:\n  external_dirs:\n    - ${HERMES_HOME}/profile-skills\n")

	hermesHome := filepath.Join(t.TempDir(), "hermes-home")
	env := map[string]string{"HERMES_HOME": profileHome} // as the daemon sets it
	skills := []SkillContextForEnv{{Name: "Review Helper", Content: "x"}}
	if err := prepareHermesHome(hermesHome, profileHome, true, skills, env, testLogger()); err != nil {
		t.Fatalf("prepareHermesHome failed: %v", err)
	}

	got := hermesExternalDirs(t, filepath.Join(hermesHome, "config.yaml"))
	want := []string{
		filepath.Join(profileHome, "profile-skills"),
		filepath.Join(profileHome, "skills"),
	}
	if strings.Join(got, "\n") != strings.Join(want, "\n") {
		t.Errorf("external_dirs =\n%v\nwant\n%v", got, want)
	}
}

// TestHermesOverlayEnvPinsHomeAfterDotenvOverride is the review's blocker 1: a
// source .env that sets HERMES_HOME must not relocate the home past the overlay.
// Hermes loads <HERMES_HOME>/.env with override=True right after profile
// resolution; we replay that last-wins/override order over the derived overlay
// .env and prove the effective HERMES_HOME stays the overlay — so bound-skill
// discovery and task-local memory keep using it — while source creds survive.
func TestHermesOverlayEnvPinsHomeAfterDotenvOverride(t *testing.T) {
	t.Parallel()
	sourceHome := t.TempDir()
	mustWrite(t, filepath.Join(sourceHome, ".env"),
		"ANTHROPIC_API_KEY=sk-source\nexport HERMES_HOME=/home/u/.hermes/profiles/coder\n")

	hermesHome := filepath.Join(t.TempDir(), "hermes-home")
	skills := []SkillContextForEnv{{Name: "Review Helper", Content: "x"}}
	if err := prepareHermesHome(hermesHome, sourceHome, false, skills, nil, testLogger()); err != nil {
		t.Fatalf("prepareHermesHome failed: %v", err)
	}

	envPath := filepath.Join(hermesHome, ".env")
	if fi, err := os.Stat(envPath); err != nil {
		t.Fatalf(".env missing: %v", err)
	} else if perm := fi.Mode().Perm(); perm != 0o600 {
		t.Errorf(".env perms = %o, want 600 (holds credentials)", perm)
	}

	env := applyDotenvOverride(t, envPath)
	if env["HERMES_HOME"] != hermesHome {
		t.Errorf("after override=True dotenv load HERMES_HOME = %q, want the overlay %q", env["HERMES_HOME"], hermesHome)
	}
	if env["ANTHROPIC_API_KEY"] != "sk-source" {
		t.Errorf("source credential dropped: ANTHROPIC_API_KEY = %q", env["ANTHROPIC_API_KEY"])
	}
	// HERMES_HOME pinned to the overlay ⇒ skill discovery and memory use the
	// overlay's own dirs.
	if _, err := os.Stat(filepath.Join(hermesHome, "skills", "review-helper", "SKILL.md")); err != nil {
		t.Errorf("bound skill not in overlay skills dir: %v", err)
	}
	if fi, err := os.Stat(filepath.Join(hermesHome, "memories")); err != nil || !fi.IsDir() {
		t.Errorf("overlay memories dir missing: %v", err)
	}
}

// TestHermesOverlayEnvCreatedWhenSourceHasNone ensures a minimal overlay .env is
// written even when the source has none, so Hermes' project-.env fallback (loaded
// with override=True only when no user .env loaded) can't relocate the home.
func TestHermesOverlayEnvCreatedWhenSourceHasNone(t *testing.T) {
	t.Parallel()
	sourceHome := t.TempDir() // no .env present
	hermesHome := filepath.Join(t.TempDir(), "hermes-home")
	skills := []SkillContextForEnv{{Name: "Review Helper", Content: "x"}}
	if err := prepareHermesHome(hermesHome, sourceHome, false, skills, nil, testLogger()); err != nil {
		t.Fatalf("prepareHermesHome failed: %v", err)
	}
	env := applyDotenvOverride(t, filepath.Join(hermesHome, ".env"))
	if env["HERMES_HOME"] != hermesHome {
		t.Errorf("overlay .env must exist and pin HERMES_HOME even with no source .env; got %q", env["HERMES_HOME"])
	}
}

// applyDotenvOverride replays python-dotenv's single-file override=True load over
// a .env: KEY=VALUE lines in order, last assignment wins, surrounding quotes and
// a leading `export` stripped. It mirrors how Hermes loads <HERMES_HOME>/.env.
func applyDotenvOverride(t *testing.T, path string) map[string]string {
	t.Helper()
	data, err := os.ReadFile(path)
	if err != nil {
		t.Fatalf("read overlay .env: %v", err)
	}
	env := map[string]string{}
	for _, line := range strings.Split(string(data), "\n") {
		s := strings.TrimSpace(line)
		if s == "" || strings.HasPrefix(s, "#") {
			continue
		}
		if rest := strings.TrimPrefix(s, "export"); rest != s && rest != "" && (rest[0] == ' ' || rest[0] == '\t') {
			s = strings.TrimSpace(rest)
		}
		eq := strings.IndexByte(s, '=')
		if eq <= 0 {
			continue
		}
		key := strings.TrimSpace(s[:eq])
		val := strings.TrimSpace(s[eq+1:])
		if len(val) >= 2 && (val[0] == '\'' || val[0] == '"') && val[len(val)-1] == val[0] {
			val = val[1 : len(val)-1]
		}
		env[key] = val // last wins (override=True)
	}
	return env
}

// TestHermesRootFromHomeResolvesSymlinks is the review's blocker 2: a HERMES_HOME
// symlinked into <native>/profiles/<x> must root at native (so -p default
// re-roots to native and -p <sibling> is a native sibling), which requires
// resolving symlinks for the containment decision — lexical containment alone
// would treat the symlink path as its own root.
func TestHermesRootFromHomeResolvesSymlinks(t *testing.T) {
	t.Parallel()
	native := t.TempDir()
	coder := filepath.Join(native, "profiles", "coder")
	if err := os.MkdirAll(coder, 0o755); err != nil {
		t.Fatal(err)
	}
	link := filepath.Join(t.TempDir(), "coder-home")
	if err := os.Symlink(coder, link); err != nil {
		t.Skipf("symlink unsupported here: %v", err)
	}

	root := hermesRootFromHomeFor(link, native)
	if root != native {
		t.Fatalf("symlinked profile home: root = %q, want native %q", root, native)
	}
	if home, _, err := hermesProfileDir(root, "default"); err != nil || home != native {
		t.Fatalf("-p default: home=%q err=%v, want %q", home, err, native)
	}
	sibling := filepath.Join(native, "profiles", "research")
	if home, _, err := hermesProfileDir(root, "research"); err != nil || home != sibling {
		t.Fatalf("-p sibling: home=%q err=%v, want %q", home, err, sibling)
	}
}

// TestPlatformDefaultHermesHome covers the Windows branch off a Windows host,
// including the LOCALAPPDATA-missing fallback to %USERPROFILE%\AppData\Local.
func TestPlatformDefaultHermesHome(t *testing.T) {
	t.Parallel()
	la := filepath.Join(string(filepath.Separator)+"Users", "me", "AppData", "Local")
	home := filepath.Join(string(filepath.Separator)+"home", "me")

	if got, want := platformDefaultHermesHomeFor("windows", la, home), filepath.Join(la, "hermes"); got != want {
		t.Errorf("windows: got %q, want %q", got, want)
	}
	// No LOCALAPPDATA → %USERPROFILE%\AppData\Local\hermes, matching Hermes.
	if got, want := platformDefaultHermesHomeFor("windows", "", home), filepath.Join(home, "AppData", "Local", "hermes"); got != want {
		t.Errorf("windows no LOCALAPPDATA: got %q, want %q", got, want)
	}
	if got, want := platformDefaultHermesHomeFor("linux", la, home), filepath.Join(home, ".hermes"); got != want {
		t.Errorf("linux: got %q, want %q", got, want)
	}
}

// TestHermesOverlayDoesNotMirrorStickyProfile is the regression for the sticky
// active_profile bypass: active_profile and profiles/ from the shared home must
// NOT be mirrored into the overlay, or Hermes would follow the sticky profile at
// startup and redirect HERMES_HOME past the overlay.
func TestHermesOverlayDoesNotMirrorStickyProfile(t *testing.T) {
	t.Parallel()
	sharedHome := t.TempDir()
	mustWrite(t, filepath.Join(sharedHome, "config.yaml"), "model: hermes-4\n")
	mustWrite(t, filepath.Join(sharedHome, "active_profile"), "coder")
	mustWrite(t, filepath.Join(sharedHome, "profiles", "coder", "config.yaml"), "model: coder\n")

	hermesHome := filepath.Join(t.TempDir(), "hermes-home")
	skills := []SkillContextForEnv{{Name: "Review Helper", Content: "x"}}
	if err := prepareHermesHome(hermesHome, sharedHome, false, skills, nil, testLogger()); err != nil {
		t.Fatalf("prepareHermesHome failed: %v", err)
	}
	for _, name := range []string{"active_profile", "profiles"} {
		if _, err := os.Lstat(filepath.Join(hermesHome, name)); !os.IsNotExist(err) {
			t.Errorf("%s must not be mirrored into the overlay (sticky-profile bypass)", name)
		}
	}
}

// TestPrepareHermesHomeFailsOnMissingNamedProfile asserts an explicitly named
// profile whose home doesn't exist fails closed rather than silently seeding
// from an empty dir (which would drop the user's auth/config), matching Hermes'
// own sys.exit(1).
func TestPrepareHermesHomeFailsOnMissingNamedProfile(t *testing.T) {
	t.Parallel()
	base := t.TempDir()
	missingProfileHome := filepath.Join(base, "profiles", "does-not-exist")
	hermesHome := filepath.Join(t.TempDir(), "hermes-home")
	skills := []SkillContextForEnv{{Name: "Review Helper", Content: "x"}}
	if err := prepareHermesHome(hermesHome, missingProfileHome, true, skills, nil, testLogger()); err == nil {
		t.Fatal("expected a missing named profile home to fail closed")
	}
}

// TestPrepareHermesNoSkillsLeavesHomeUnset is the regression for the review's
// top blocker: a Hermes task with no bound skills must NOT get a redirected
// HERMES_HOME.
func TestPrepareHermesNoSkillsLeavesHomeUnset(t *testing.T) {
	t.Parallel()
	env, err := Prepare(PrepareParams{
		WorkspacesRoot: t.TempDir(),
		WorkspaceID:    "ws-hermes-noskill",
		TaskID:         "aaaa1111-2222-3333-4444-555566667777",
		Provider:       "hermes",
		Task:           TaskContextForEnv{IssueID: "no-skill"},
	}, testLogger())
	if err != nil {
		t.Fatalf("Prepare failed: %v", err)
	}
	defer env.Cleanup(true)

	if env.HermesHome != "" {
		t.Errorf("skill-less Hermes task must not redirect HERMES_HOME, got %q", env.HermesHome)
	}
	if _, err := os.Stat(filepath.Join(env.RootDir, "hermes-home")); !os.IsNotExist(err) {
		t.Error("no hermes-home overlay should be created for a skill-less task")
	}
}

// TestReuseHermesTearsDownWhenSkillsRemoved covers the resume path: a task that
// had a skill and lost its last one must drop the redirect and remove the
// overlay.
func TestReuseHermesTearsDownWhenSkillsRemoved(t *testing.T) {
	t.Parallel()
	sharedHome := t.TempDir()
	mustWrite(t, filepath.Join(sharedHome, "config.yaml"), "model: hermes-4\n")

	withSkill := TaskContextForEnv{
		IssueID:     "hermes-resume",
		AgentSkills: []SkillContextForEnv{{Name: "Review Helper", Content: "Help review."}},
	}
	env, err := Prepare(PrepareParams{
		WorkspacesRoot:   t.TempDir(),
		WorkspaceID:      "ws-hermes-resume",
		TaskID:           "bbbb1111-2222-3333-4444-555566667777",
		Provider:         "hermes",
		HermesSourceHome: sharedHome,
		Task:             withSkill,
	}, testLogger())
	if err != nil {
		t.Fatalf("Prepare failed: %v", err)
	}
	defer env.Cleanup(true)

	if env.HermesHome == "" {
		t.Fatal("expected HERMES_HOME redirect for a task with a bound skill")
	}
	overlayDir := filepath.Join(env.RootDir, "hermes-home")

	if reused := Reuse(ReuseParams{WorkDir: env.WorkDir, Provider: "hermes", HermesSourceHome: sharedHome, Task: withSkill}, testLogger()); reused == nil {
		t.Fatal("Reuse with skill returned nil")
	} else if reused.HermesHome == "" {
		t.Error("resume with a bound skill should keep the redirect")
	}

	noSkill := TaskContextForEnv{IssueID: "hermes-resume"}
	reused := Reuse(ReuseParams{WorkDir: env.WorkDir, Provider: "hermes", HermesSourceHome: sharedHome, Task: noSkill}, testLogger())
	if reused == nil {
		t.Fatal("Reuse without skill returned nil")
	}
	if reused.HermesHome != "" {
		t.Errorf("removing the last skill should clear HERMES_HOME, got %q", reused.HermesHome)
	}
	if _, err := os.Stat(overlayDir); !os.IsNotExist(err) {
		t.Error("stale hermes-home overlay should be removed on teardown")
	}
}

func mustWrite(t *testing.T, path, content string) {
	t.Helper()
	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
		t.Fatalf("mkdir for %s: %v", path, err)
	}
	if err := os.WriteFile(path, []byte(content), 0o644); err != nil {
		t.Fatalf("write %s: %v", path, err)
	}
}