package api

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

	"hamlab/internal/compose"
	"hamlab/internal/config"
	"hamlab/internal/store"
)

// A stack deployed by an orchestrator running in a container records the path its compose
// file had inside that container. Resolving it has to work both while the orchestrator is
// running — compose is then run inside it — and after it has been removed, where the same
// mount is only remembered and compose has to run on the host instead.
func TestResolveThroughMounts(t *testing.T) {
	root := t.TempDir()
	dir := filepath.Join(root, "orch", "stacks", "app")
	if err := os.MkdirAll(dir, 0o755); err != nil {
		t.Fatal(err)
	}
	file := filepath.Join(dir, "compose.yaml")
	if err := os.WriteFile(file, []byte("services: {}\n"), 0o644); err != nil {
		t.Fatal(err)
	}
	inner := "/app/data/stacks/app/compose.yaml"

	for _, tc := range []struct {
		name, container, wantVia string
	}{
		{"orchestrator running", "orch", "orch"},
		{"orchestrator removed", "", ""},
	} {
		t.Run(tc.name, func(t *testing.T) {
			st := stack{Name: "app", File: inner, Files: []string{inner}}
			st.resolve([]mountMap{{tc.container, "/app/data", filepath.Join(root, "orch")}})
			if !st.Editable {
				t.Fatalf("not editable: %s", st.Note)
			}
			if st.HostFile != file {
				t.Errorf("host file = %q, want %q", st.HostFile, file)
			}
			if st.Via != tc.wantVia {
				t.Errorf("via = %q, want %q", st.Via, tc.wantVia)
			}
		})
	}

	// Nothing explains the path: the stack is listed, but read-only and says why.
	st := stack{Name: "app", File: inner, Files: []string{inner}}
	st.resolve(nil)
	if st.Editable || st.Note == "" {
		t.Errorf("unresolvable stack should be read-only with a note, got editable=%v note=%q", st.Editable, st.Note)
	}
}

// Every file of a multi-file stack must resolve through the same place. Redeploying from
// the first file alone would silently drop whatever the override set.
func TestResolveRefusesSplitStack(t *testing.T) {
	root := t.TempDir()
	dir := filepath.Join(root, "orch", "stacks", "app")
	if err := os.MkdirAll(dir, 0o755); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(filepath.Join(dir, "compose.yaml"), []byte("services: {}\n"), 0o644); err != nil {
		t.Fatal(err)
	}
	st := stack{Name: "app", File: "/app/data/stacks/app/compose.yaml", Files: []string{
		"/app/data/stacks/app/compose.yaml",
		"/app/data/stacks/app/override.yaml", // never written: not on disk
	}}
	st.resolve([]mountMap{{"orch", "/app/data", filepath.Join(root, "orch")}})
	if st.Editable {
		t.Error("a stack with a file that cannot be found should not be editable")
	}
}

// A schedule made while an orchestrator was running says "run compose inside that
// container". When the container is gone the schedule must still work, against the same
// files on the host — otherwise retiring the orchestrator silently breaks every scheduled
// update made before it went.
func TestRepointSurvivesAMissingContainer(t *testing.T) {
	root := t.TempDir()
	dir := filepath.Join(root, "orch", "stacks", "app")
	if err := os.MkdirAll(dir, 0o755); err != nil {
		t.Fatal(err)
	}
	host := filepath.Join(dir, "compose.yaml")
	if err := os.WriteFile(host, []byte("services: {}\n"), 0o644); err != nil {
		t.Fatal(err)
	}
	db, err := store.Open(filepath.Join(root, "state.json"))
	if err != nil {
		t.Fatal(err)
	}
	if err := db.Update(func(st *store.State) {
		st.Mounts = []store.RememberedMount{{Container: "gone-orchestrator", Dest: "/app/data", Src: filepath.Join(root, "orch")}}
	}); err != nil {
		t.Fatal(err)
	}

	in := compose.Spec{Project: "app", Files: []string{"/app/data/stacks/app/compose.yaml"}, Via: "gone-orchestrator", Tool: "docker"}
	got := repoint(context.Background(), db, in)
	if got.Via != "" {
		t.Errorf("via = %q, want it dropped", got.Via)
	}
	if len(got.Files) != 1 || got.Files[0] != host {
		t.Errorf("files = %v, want [%s]", got.Files, host)
	}

	// Nothing remembered: the schedule is left exactly as it was rather than pointed at a
	// guess. It will fail loudly, which is better than deploying the wrong file.
	empty, err := store.Open(filepath.Join(root, "empty.json"))
	if err != nil {
		t.Fatal(err)
	}
	if got := repoint(context.Background(), empty, in); got.Via != in.Via || len(got.Files) != 1 || got.Files[0] != in.Files[0] {
		t.Errorf("unresolvable spec was changed: %+v", got)
	}
}

// Where new stacks go: Ham Lab's own <data dir>/stacks is always offered, first and as the
// default, whether or not anything is in it yet. A folder this machine already keeps stacks
// in — two or more deployed from it — is offered too, but never ahead of Ham Lab's own.
func TestHomesDefaultToDataDir(t *testing.T) {
	root := t.TempDir()
	cfg := config.Default(filepath.Join(root, "data", "config.json"))
	s := &Server{cfg: cfg}
	own := filepath.Join(root, "data", "stacks")
	legacy := filepath.Join(root, "home", "stacks", "box")
	deployed := func(dir, name string) stack {
		f := filepath.Join(dir, name, "compose.yaml")
		return stack{Name: name, Containers: []string{name + "-1"}, Files: []string{f}, File: f, HostFiles: []string{f}, HostFile: f, Editable: true}
	}

	// Nothing deployed anywhere: one home, Ham Lab's own.
	homes := s.homesOf(nil)
	if len(homes) != 1 || homes[0].Dir != own || !homes[0].Default {
		t.Fatalf("empty machine: homes = %+v, want just %s as default", homes, own)
	}

	// Two stacks deployed from a pre-existing folder: it is offered, after Ham Lab's own.
	homes = s.homesOf([]stack{deployed(legacy, "a"), deployed(legacy, "b")})
	if len(homes) != 2 || homes[0].Dir != own || !homes[0].Default || homes[1].Dir != legacy || homes[1].Default || homes[1].Stacks != 2 {
		t.Fatalf("legacy folder: homes = %+v, want [%s (default), %s]", homes, own, legacy)
	}

	// One lone stack elsewhere says nothing about where the next should go; one in Ham Lab's
	// own folder is already home.
	homes = s.homesOf([]stack{deployed(filepath.Join(root, "home", "apps"), "orchestrator"), deployed(own, "c")})
	if len(homes) != 1 || homes[0].Dir != own || homes[0].Stacks != 1 || !homes[0].Default {
		t.Fatalf("lone stacks: homes = %+v, want just %s", homes, own)
	}
}