package releasekit_test

import (
	"archive/zip"
	"context"
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"testing"

	releasekit "go.maximumdirect.net/releasekit"
)

func TestPrepareBuildDependenciesSelectedModuleGraphs(t *testing.T) {
	repo := t.TempDir()
	nested := filepath.Join(repo, "nested")
	child := filepath.Join(nested, "child")
	if err := os.MkdirAll(child, 0755); err != nil {
		t.Fatal(err)
	}
	write := func(path, value string) {
		t.Helper()
		if err := os.WriteFile(path, []byte(value), 0644); err != nil {
			t.Fatal(err)
		}
	}
	write(filepath.Join(repo, "go.mod"), "module example.invalid/root\n\ngo 1.25.0\n\nrequire example.invalid/rootdep v1.0.0\n")
	write(filepath.Join(nested, "go.mod"), "module example.invalid/nested\n\ngo 1.25.0\n\nrequire example.invalid/nesteddep v1.0.0\n")
	alt := filepath.Join(repo, "alternate.mod")
	write(alt, "module example.invalid/alternate\n\ngo 1.25.0\n")
	buildGit(t, repo, "init", "-b", "main")
	buildGit(t, repo, "config", "user.name", "Test")
	buildGit(t, repo, "config", "user.email", "test@example.invalid")
	buildGit(t, repo, "add", ".")
	buildGit(t, repo, "commit", "-m", "fixture")
	proxy := t.TempDir()
	for _, dep := range []string{"rootdep", "nesteddep"} {
		writePreparationProxy(t, proxy, "example.invalid/"+dep)
	}
	t.Setenv("GOPROXY", "file://"+filepath.ToSlash(proxy))
	t.Setenv("GOSUMDB", "off")
	t.Setenv("GOPRIVATE", "")
	t.Setenv("GONOPROXY", "none")
	t.Setenv("GONOSUMDB", "*")
	t.Setenv("GOTOOLCHAIN", "local")
	t.Setenv("GOWORK", "off")
	realGo, err := exec.LookPath("go")
	if err != nil {
		t.Fatal(err)
	}
	for _, tc := range []struct {
		name, module, dep, modulePath string
		persistent                    bool
	}{
		{"inherited root", "", "rootdep", "example.invalid/root", false},
		{"persistent nested", "nested", "nesteddep", "example.invalid/nested", true},
	} {
		t.Run(tc.name, func(t *testing.T) {
			cache := filepath.Join(t.TempDir(), "cache")
			t.Setenv("GOMODCACHE", cache)
			envFile := filepath.Join(t.TempDir(), "goenv")
			flags := "-modfile=" + alt + " -modcacherw"
			if tc.persistent {
				write(envFile, "GOFLAGS="+flags+"\n")
				t.Setenv("GOENV", envFile)
				t.Setenv("GOFLAGS", "")
				if err := os.Unsetenv("GOFLAGS"); err != nil {
					t.Fatal(err)
				}
			} else {
				t.Setenv("GOENV", "off")
				t.Setenv("GOFLAGS", flags)
			}
			// Without the explicit override, the alternate file has no dependencies.
			negativeCache := filepath.Join(t.TempDir(), "negative")
			command := exec.Command(realGo, "mod", "download")
			command.Dir = repo
			command.Env = append(os.Environ(), "GOMODCACHE="+negativeCache)
			if out, err := command.CombinedOutput(); err != nil {
				t.Fatalf("negative control: %v: %s", err, out)
			}
			if _, err := os.Stat(filepath.Join(negativeCache, "cache", "download", "example.invalid", tc.dep)); !os.IsNotExist(err) {
				t.Fatalf("alternate graph unexpectedly downloaded %s: %v", tc.dep, err)
			}
			if err := releasekit.PrepareBuildDependencies(context.Background(), releasekit.DependencyPreparationRequest{RepositoryDir: child, ModuleDir: tc.module}); err != nil {
				t.Fatal(err)
			}
			if _, err := os.Stat(filepath.Join(cache, "cache", "download", "example.invalid", tc.dep, "@v", "v1.0.0.zip")); err != nil {
				t.Fatalf("selected dependency missing: %v", err)
			}
			other := "rootdep"
			if tc.dep == other {
				other = "nesteddep"
			}
			if _, err := os.Stat(filepath.Join(cache, "cache", "download", "example.invalid", other)); !os.IsNotExist(err) {
				t.Fatalf("unexpected other graph: %v", err)
			}
			info, err := os.Stat(filepath.Join(cache, "example.invalid", tc.dep+"@v1.0.0"))
			if err != nil || info.Mode().Perm()&0200 == 0 {
				t.Fatalf("-modcacherw did not take effect: %v, %v", info, err)
			}
			result, err := releasekit.Build(context.Background(), releasekit.BuildRequest{RepositoryDir: child, ModuleDir: tc.module, Version: "v1.2.3"})
			expected := repo
			if tc.module != "" {
				expected = nested
			}
			if err != nil || result.RepositoryDir != repo || result.ModuleDir != expected || result.ModulePath != tc.modulePath {
				t.Fatalf("build identity = %#v, error = %v", result, err)
			}
		})
	}
	// Standalone package subdirectories retain Go's upward module discovery.
	standalone := t.TempDir()
	pkg := filepath.Join(standalone, "pkg")
	if err := os.Mkdir(pkg, 0755); err != nil {
		t.Fatal(err)
	}
	write(filepath.Join(standalone, "go.mod"), "module example.invalid/standalone\n\ngo 1.25.0\n\nrequire example.invalid/rootdep v1.0.0\n")
	t.Setenv("GOENV", "off")
	t.Setenv("GOFLAGS", "-modfile="+alt+" -modcacherw")
	cache := filepath.Join(t.TempDir(), "cache")
	t.Setenv("GOMODCACHE", cache)
	if err := releasekit.PrepareBuildDependencies(context.Background(), releasekit.DependencyPreparationRequest{RepositoryDir: pkg}); err != nil {
		t.Fatal(err)
	}
	if _, err := os.Stat(filepath.Join(cache, "cache", "download", "example.invalid", "rootdep", "@v", "v1.0.0.zip")); err != nil {
		t.Fatal(err)
	}
}

func writePreparationProxy(t *testing.T, proxy, module string) {
	t.Helper()
	dir := filepath.Join(proxy, filepath.FromSlash(module), "@v")
	if err := os.MkdirAll(dir, 0755); err != nil {
		t.Fatal(err)
	}
	mod := "module " + module + "\n\ngo 1.25.0\n"
	for name, contents := range map[string]string{"v1.0.0.mod": mod, "v1.0.0.info": `{"Version":"v1.0.0","Time":"2026-01-01T00:00:00Z"}`, "list": "v1.0.0\n"} {
		if err := os.WriteFile(filepath.Join(dir, name), []byte(contents), 0644); err != nil {
			t.Fatal(err)
		}
	}
	file, err := os.Create(filepath.Join(dir, "v1.0.0.zip"))
	if err != nil {
		t.Fatal(err)
	}
	z := zip.NewWriter(file)
	for name, contents := range map[string]string{"go.mod": mod, "dep.go": "package dep\n"} {
		w, err := z.Create(fmt.Sprintf("%s@v1.0.0/%s", module, name))
		if err != nil {
			t.Fatal(err)
		}
		if _, err := w.Write([]byte(contents)); err != nil {
			t.Fatal(err)
		}
	}
	if err := z.Close(); err != nil {
		t.Fatal(err)
	}
	if err := file.Close(); err != nil {
		t.Fatal(err)
	}
}