package main

import (
	"fmt"
	"regexp"
	"strings"
	"testing"
)

// Docker's own directory is never the mesh's (novox/hq issue 452). The node-engine places nothing in or
// below the container runtimes' data (novox/hq issue 339), so a module directory that resolves there is
// refused on the machine and fails the whole apply. The merge gate composes a change but does not apply it,
// so it passed #205's `"place": "."`, which the controller resolves to <root>/<module>: /var/lib/docker.

// runtimeTrees are the trees the node-engine refuses to place in (mesh-host internal/apply/placement_guard.go).
var runtimeTrees = []string{"/var/lib/docker", "/var/lib/containers", "/var/lib/containerd"}

// defaultDataRoot is the controller's root for placed directories when a node states none
// (mesh-controller internal/catalogue/dir_into.go).
const defaultDataRoot = "/var/lib"

// placedDirs resolves each directory resource as the controller's dirsFor does on a node with the default
// data root: a stated path as written, `"place": "."` as <root>/<module>, `"place": "mesh"` as
// <root>/mesh/<module>, and neither as <root>/<module>/<id>.
func placedDirs(t *testing.T, m manifestForLogs) map[string]string {
	t.Helper()
	dirs := map[string]string{}
	for _, r := range m.Resources {
		if r["type"] != "directory" {
			continue
		}
		id := fmt.Sprint(r["id"])
		if p, ok := r["path"].(string); ok && p != "" {
			dirs[id] = strings.TrimRight(p, "/")
			continue
		}
		switch r["place"] {
		case ".":
			dirs[id] = defaultDataRoot + "/docker"
		case "mesh":
			dirs[id] = defaultDataRoot + "/mesh/docker"
		default:
			dirs[id] = defaultDataRoot + "/docker/" + id
		}
	}
	return dirs
}

func inRuntimeTree(p string) string {
	for _, tree := range runtimeTrees {
		if p == tree || strings.HasPrefix(p, tree+"/") {
			return tree
		}
	}
	return ""
}

// TestNothingIsPlacedInTheRuntimesData: no directory of the module resolves into Docker's own directory or
// another runtime's, and no file, process or environment value names a path there through ${dir:…} or as
// written.
func TestNothingIsPlacedInTheRuntimesData(t *testing.T) {
	m := readManifestForLogs(t)
	dirs := placedDirs(t, m)
	for id, p := range dirs {
		if tree := inRuntimeTree(p); tree != "" {
			t.Errorf("directory %q resolves to %s, inside %s: the container runtime's data, never the mesh's (novox/hq issues 339, 452)", id, p, tree)
		}
	}
	ref := regexp.MustCompile(`\$\{dir:([a-z0-9][a-z0-9-]*)\}`)
	fill := func(s string) string {
		return ref.ReplaceAllStringFunc(s, func(r string) string {
			if p, ok := dirs[ref.FindStringSubmatch(r)[1]]; ok {
				return p
			}
			return r
		})
	}
	for _, r := range m.Resources {
		id := fmt.Sprint(r["id"])
		var named []string
		if p, ok := r["path"].(string); ok {
			named = append(named, p)
		}
		if env, ok := r["env"].(map[string]any); ok {
			for _, v := range env {
				if s, ok := v.(string); ok {
					named = append(named, s)
				}
			}
		}
		for _, p := range named {
			if tree := inRuntimeTree(fill(p)); tree != "" {
				t.Errorf("resource %q names %s, inside %s: the container runtime's data, never the mesh's (novox/hq issues 339, 452)", id, fill(p), tree)
			}
		}
	}
}

// TestLogRotationIsInTheModulesOwnDirectory: the step reads the file the mesh writes, in a directory the mesh
// places for the module, not one Docker keeps.
func TestLogRotationIsInTheModulesOwnDirectory(t *testing.T) {
	m := readManifestForLogs(t)
	dirs := placedDirs(t, m)
	if got, want := dirs["state"], "/var/lib/mesh/docker"; got != want {
		t.Fatalf("the module's state directory resolves to %q, want %q (novox/hq issue 452)", got, want)
	}
	file, _ := resourceByID(m, "log-rotation")
	step, _ := resourceByID(m, "log-rotation-check")
	if file == nil || step == nil {
		t.Fatal("log-rotation and log-rotation-check are declared")
	}
	env, _ := step["env"].(map[string]any)
	if file["path"] != env["DOCKER_LOG_ROTATION"] {
		t.Errorf("the step reads %v, the mesh writes %v: one file", env["DOCKER_LOG_ROTATION"], file["path"])
	}
	if file["path"] != "${dir:state}/log-rotation.conf" {
		t.Errorf("log-rotation is at %v, want ${dir:state}/log-rotation.conf", file["path"])
	}
}