package validation

import (
	"context"
	"errors"
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"testing"
)

func TestRunCompilesTargetsAfterTestAndVetInSelectionOrder(t *testing.T) {
	logPath := installGoShim(t, "", false)
	targets := []Target{{OS: "linux", Arch: "amd64"}, {OS: "linux", Arch: "arm64"}, {OS: "darwin", Arch: "arm64"}}
	err := Run(context.Background(), Request{
		RepositoryDir: t.TempDir(),
		Settings:      Settings{FullVet: true, CompileTargets: targets},
	})
	if err != nil {
		t.Fatalf("Run() error = %v", err)
	}

	var commands []string
	for _, command := range readGoShimLog(t, logPath) {
		if strings.HasPrefix(command, "test ") || strings.HasPrefix(command, "vet ") || strings.HasPrefix(command, "build ") {
			commands = append(commands, command)
		}
	}
	if len(commands) != len(targets)+2 || !strings.HasPrefix(commands[0], "test ") || !strings.HasPrefix(commands[1], "vet ") {
		t.Fatalf("validation commands = %q, want test, vet, then one build per target", commands)
	}
	for index, target := range targets {
		command := commands[index+2]
		if !strings.HasPrefix(command, "build ") {
			t.Fatalf("command %d = %q, want package build", index+2, command)
		}
		for _, argument := range []string{"build", "-mod=readonly", "-o " + os.DevNull, "./..."} {
			if !strings.Contains(" "+command+" ", " "+argument+" ") {
				t.Errorf("build command %q does not contain %q", command, argument)
			}
		}
		if got, want := strings.Fields(command)[0], "build"; got != want {
			t.Errorf("command = %q, want %q", got, want)
		}
		if target.OS == "" || target.Arch == "" {
			t.Fatalf("test target is incomplete: %#v", target)
		}
	}

	environments, err := os.ReadFile(os.Getenv("RELEASEKIT_GO_ENV_LOG"))
	if err != nil {
		t.Fatal(err)
	}
	got := strings.Split(strings.TrimSpace(string(environments)), "\n")
	if len(got) != len(targets) {
		t.Fatalf("static build environments = %q, want %d entries", got, len(targets))
	}
	for index, target := range targets {
		if want := fmt.Sprintf("%s/%s|0", target.OS, target.Arch); got[index] != want {
			t.Errorf("static build environment %d = %q, want %q", index, got[index], want)
		}
	}
}

func TestRunAttributesTargetCompileFailureAndStops(t *testing.T) {
	logPath := installGoShim(t, "darwin/arm64", false)
	targets := []Target{{OS: "linux", Arch: "amd64"}, {OS: "darwin", Arch: "arm64"}, {OS: "windows", Arch: "amd64"}}
	err := Run(context.Background(), Request{
		RepositoryDir: t.TempDir(),
		Settings:      Settings{FullVet: true, CompileTargets: targets},
	})
	var failure *Failure
	if !errors.As(err, &failure) || failure.Check != PackageCompile {
		t.Fatalf("Run() error = %v, want a package-compile failure", err)
	}
	if len(failure.Findings) != 1 || failure.Findings[0].Target != "darwin/arm64" {
		t.Fatalf("package compilation findings = %#v, want target darwin/arm64", failure.Findings)
	}
	var exitError *exec.ExitError
	if !errors.As(err, &exitError) {
		t.Fatalf("Run() error = %v, want the Go command failure preserved", err)
	}
	var commands []string
	for _, command := range readGoShimLog(t, logPath) {
		if strings.HasPrefix(command, "test ") || strings.HasPrefix(command, "vet ") || strings.HasPrefix(command, "build ") {
			commands = append(commands, command)
		}
	}
	if len(commands) != 4 || !strings.HasPrefix(commands[0], "test ") || !strings.HasPrefix(commands[1], "vet ") || !strings.HasPrefix(commands[2], "build ") || !strings.HasPrefix(commands[3], "build ") {
		t.Fatalf("validation commands after target failure = %q, want test, vet, two builds", commands)
	}
}

func TestRunRejectsIncompleteCompileTargets(t *testing.T) {
	installGoShim(t, "", false)
	for _, target := range []Target{{OS: "linux"}, {Arch: "amd64"}, {OS: " ", Arch: "amd64"}, {OS: "linux/other", Arch: "amd64"}} {
		err := Run(context.Background(), Request{
			RepositoryDir: t.TempDir(),
			Settings:      Settings{CompileTargets: []Target{target}},
		})
		var failure *Failure
		if !errors.As(err, &failure) || failure.Check != PackageCompile {
			t.Errorf("Run(%#v) error = %v, want a package-compile validation failure", target, err)
			continue
		}
		if len(failure.Findings) != 1 || failure.Findings[0].Target != target.OS+"/"+target.Arch {
			t.Errorf("Run(%#v) findings = %#v, want the incomplete target", target, failure.Findings)
		}
	}
}

func TestRunCompilesSourceOnlyAndExecutablePackagesWithoutArtifacts(t *testing.T) {
	fixtures := []struct {
		name  string
		files map[string]string
	}{
		{
			name: "source library",
			files: map[string]string{
				"library.go": "package fixture\n\nconst Value = 1\n",
			},
		},
		{
			name: "single main",
			files: map[string]string{
				"library.go":      "package fixture\n\nconst Value = 1\n",
				"cmd/app/main.go": "package main\n\nfunc main() {}\n",
			},
		},
		{
			name: "multiple mains with repeated basenames",
			files: map[string]string{
				"library.go":           "package fixture\n\nconst Value = 1\n",
				"cmd/one/tool/main.go": "package main\n\nfunc main() {}\n",
				"cmd/two/tool/main.go": "package main\n\nfunc main() {}\n",
			},
		},
	}
	for _, fixture := range fixtures {
		t.Run(fixture.name, func(t *testing.T) {
			module := writeCompileFixture(t, fixture.files)
			before := readCompileFixture(t, module, fixture.files)
			var targets []Target
			if fixture.name == "source library" {
				targets = []Target{{OS: "linux", Arch: "amd64"}, {OS: "linux", Arch: "arm64"}, {OS: "darwin", Arch: "arm64"}}
			} else {
				targets = []Target{{OS: "linux", Arch: "amd64"}}
			}
			if err := Run(context.Background(), Request{
				RepositoryDir: module,
				Settings:      Settings{CompileTargets: targets},
			}); err != nil {
				t.Fatalf("Run() error = %v", err)
			}
			after := readCompileFixture(t, module, fixture.files)
			for path, contents := range before {
				if string(after[path]) != string(contents) {
					t.Errorf("candidate file %q changed during compilation", path)
				}
			}
		})
	}
}

func writeCompileFixture(t *testing.T, files map[string]string) string {
	t.Helper()
	module := t.TempDir()
	if err := os.WriteFile(filepath.Join(module, "go.mod"), []byte("module example.com/compilefixture\n\ngo 1.25.0\n"), 0o600); err != nil {
		t.Fatal(err)
	}
	for path, contents := range files {
		filename := filepath.Join(module, filepath.FromSlash(path))
		if err := os.MkdirAll(filepath.Dir(filename), 0o700); err != nil {
			t.Fatal(err)
		}
		if err := os.WriteFile(filename, []byte(contents), 0o600); err != nil {
			t.Fatal(err)
		}
	}
	return module
}

func readCompileFixture(t *testing.T, module string, files map[string]string) map[string][]byte {
	t.Helper()
	contents := make(map[string][]byte, len(files)+1)
	for _, path := range append([]string{"go.mod"}, fixturePaths(files)...) {
		data, err := os.ReadFile(filepath.Join(module, filepath.FromSlash(path)))
		if err != nil {
			t.Fatal(err)
		}
		contents[path] = data
	}
	return contents
}

func fixturePaths(files map[string]string) []string {
	paths := make([]string, 0, len(files))
	for path := range files {
		paths = append(paths, path)
	}
	return paths
}