package apply

import (
	"context"
	"os"
	"strings"
	"testing"

	"github.com/novox/mesh-host/internal/store"
)

// An operator-owned path the module reaches but does not own (novox/hq ADR 0051).
//
// The host confirms it is present and changes nothing: it does not create it, chown it or set its
// mode, because the media library and the download spool are the operator's and several modules
// share them. This is the opposite of a directory on every axis, and the whole reason the two are
// different shapes.
func TestAnAccessPresentIsConfirmedAndNothingIsChanged(t *testing.T) {
	dir := t.TempDir() // the operator's directory, already there
	d := declare(t, `{"id":"lib","type":"access","path":"`+dir+`","mode":"read-write"}`)

	report, _, err := Apply(context.Background(), archHost(t), d, store.State{},
		store.OriginDeclared, noServices, nil, nil)
	if err != nil {
		t.Fatalf("an operator-owned path that is present was refused: %v", err)
	}
	if report.Changed() {
		t.Fatalf("confirming an access reported a change; the host owns nothing about it")
	}
	if _, statErr := os.Stat(dir); statErr != nil {
		t.Fatalf("the operator's directory was disturbed: %v", statErr)
	}
}

// Absent is refused, not created. A bind mount whose source does not exist is made by the
// container runtime as root, with whatever mode it picks — the silent wrong-ownership
// 04-ISSUES/026 records. So the host says plainly that the operator must provide the path, rather
// than conjuring a directory it does not own.
func TestAnAccessThatIsAbsentIsRefusedClearlyAndNotCreated(t *testing.T) {
	missing := t.TempDir() + "/media/library" // named, never created
	d := declare(t, `{"id":"lib","type":"access","path":"`+missing+`"}`)

	_, _, err := Apply(context.Background(), archHost(t), d, store.State{},
		store.OriginDeclared, noServices, nil, nil)
	if err == nil {
		t.Fatal("an absent operator-owned path was accepted, and would be created as root by the runtime")
	}
	if !strings.Contains(err.Error(), "the operator must provide") ||
		!strings.Contains(err.Error(), "does not own") {
		t.Fatalf("the refusal does not say whose the path is: %v", err)
	}
	if _, statErr := os.Stat(missing); statErr == nil {
		t.Fatal("the host created the path it does not own")
	}
}

// Undeclaring an access never removes the path. Unassigning the module that reached the media
// library must not delete the library — that is the data loss ADR 0030 exists to prevent, on a
// directory the mesh never made. The record is dropped; the operator's data is left exactly as it
// is.
func TestAnUndeclaredAccessLeavesTheOperatorsPathAlone(t *testing.T) {
	lib := t.TempDir() // the operator's library
	keep := t.TempDir()
	if err := os.WriteFile(lib+"/a-real-file", []byte("the operator's data"), 0o644); err != nil {
		t.Fatal(err)
	}

	d := declare(t, `{"id":"lib","type":"access","path":"`+lib+`","mode":"read"}`)
	_, state, err := Apply(context.Background(), archHost(t), d, store.State{},
		store.OriginDeclared, noServices, nil, nil)
	if err != nil {
		t.Fatal(err)
	}

	// The module is unassigned: the mesh no longer declares the access.
	empty := declare(t, `{"id":"unrelated","type":"directory","path":"`+keep+`"}`)
	report, _, err := Apply(context.Background(), archHost(t), empty, state,
		store.OriginDeclared, noServices, nil, nil)
	if err != nil {
		t.Fatal(err)
	}

	if _, statErr := os.Stat(lib); statErr != nil {
		t.Fatalf("the operator's library was removed when the module stopped reaching it: %v", statErr)
	}
	if _, statErr := os.Stat(lib + "/a-real-file"); statErr != nil {
		t.Fatalf("the operator's data was removed: %v", statErr)
	}
	var forgot bool
	for _, o := range report.Outcomes {
		if o.Type == "access" && o.Action == "forgotten" {
			forgot = true
		}
	}
	if !forgot {
		t.Errorf("dropping an access was not reported as forgotten: %+v", report.Outcomes)
	}
}