package releasekit_test

import (
	"bytes"
	"context"
	"crypto/sha256"
	"encoding/hex"
	"errors"
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"runtime"
	"strings"
	"testing"
	"time"

	releasekit "gitea.maximumdirect.net/eric/ReleaseKit"
)

func TestBuildCreatesSelectedTargetsAndInjectsVersion(t *testing.T) {
	repository := newBuildConsumer(t, `package main

import (
	"fmt"
	"os"

	"gitea.maximumdirect.net/eric/ReleaseKit/buildinfo"
)

func main() {
	if len(os.Args) == 2 && os.Args[1] == "version" {
		fmt.Printf("fixture %s\n", buildinfo.Version())
	}
}
`)
	outputDir := filepath.Join(t.TempDir(), "artifacts")
	t.Setenv("GOOS", "windows")
	t.Setenv("GOARCH", "arm64")
	t.Setenv("GOFLAGS", "-race")
	var progress bytes.Buffer
	result, err := releasekit.Build(context.Background(), releasekit.BuildRequest{
		RepositoryDir: repository,
		Version:       "v1.2.3",
		Spec: releasekit.BuildSpec{
			MainPackage: "./cmd/app",
			BinaryName:  "fixture",
			Targets: []releasekit.Target{
				{OS: "linux", Arch: "amd64"},
				{OS: "linux", Arch: "arm64"},
				{OS: "darwin", Arch: "arm64"},
				{OS: "linux", Arch: "amd64"},
			},
		},
		OutputDir: outputDir,
		Output:    &progress,
	})
	if err != nil {
		t.Fatalf("Build() error = %v; partial result = %#v", err, result)
	}
	if result.CandidateCommit == "" || result.CandidateCommit != buildGit(t, repository, "rev-parse", "HEAD") {
		t.Fatalf("candidate commit = %q", result.CandidateCommit)
	}
	if result.Compiler == "" || len(result.Targets) != 3 || len(result.Artifacts) != 3 {
		t.Fatalf("build result = %#v", result)
	}
	wantNames := []string{
		"fixture-v1.2.3-linux-amd64",
		"fixture-v1.2.3-linux-arm64",
		"fixture-v1.2.3-darwin-arm64",
	}
	for index, artifact := range result.Artifacts {
		if artifact.Filename != wantNames[index] || artifact.Target != result.Targets[index] {
			t.Fatalf("artifact %d = %#v", index, artifact)
		}
		contents, err := os.ReadFile(artifact.Path)
		if err != nil {
			t.Fatal(err)
		}
		digest := sha256.Sum256(contents)
		if artifact.SHA256 != hex.EncodeToString(digest[:]) {
			t.Fatalf("artifact digest = %q, want %x", artifact.SHA256, digest)
		}
	}
	if !strings.Contains(progress.String(), "checking fixture version output") {
		t.Fatalf("build progress = %q", progress.String())
	}
	for _, artifact := range result.Artifacts {
		if artifact.Target != (releasekit.Target{OS: runtime.GOOS, Arch: runtime.GOARCH}) {
			continue
		}
		command := exec.Command(artifact.Path, "version")
		output, err := command.CombinedOutput()
		if err != nil || string(output) != "fixture v1.2.3\n" {
			t.Fatalf("native version command output = %q, error = %v", output, err)
		}
		return
	}
}

func TestBuildUsesGoHostDespiteAmbientTargetEnvironment(t *testing.T) {
	repository := newBuildConsumer(t, `package main

import (
	"fmt"
	"os"
	"gitea.maximumdirect.net/eric/ReleaseKit/buildinfo"
)

func main() {
	if len(os.Args) == 2 && os.Args[1] == "version" { fmt.Printf("fixture %s\n", buildinfo.Version()) }
}
`)
	t.Setenv("GOOS", "windows")
	t.Setenv("GOARCH", "arm64")
	result, err := releasekit.Build(context.Background(), releasekit.BuildRequest{
		RepositoryDir: repository,
		Version:       "v2.3.4",
		Spec: releasekit.BuildSpec{
			MainPackage: "./cmd/app",
			BinaryName:  "fixture",
			Targets:     []releasekit.Target{{OS: "windows", Arch: "arm64"}},
		},
		OutputDir: filepath.Join(t.TempDir(), "artifacts"),
	})
	if err != nil {
		t.Fatalf("Build() error = %v; partial result = %#v", err, result)
	}
	if len(result.Artifacts) != 1 || result.Artifacts[0].Filename != "fixture-v2.3.4-windows-arm64.exe" {
		t.Fatalf("build artifacts = %#v", result.Artifacts)
	}
}

func TestBuildWithNoTargetsDoesNotInvokeCompiler(t *testing.T) {
	repository := newBuildConsumer(t, `package main
func main() {}
`)
	outputDir := filepath.Join(t.TempDir(), "must-not-be-created")
	result, err := releasekit.Build(context.Background(), releasekit.BuildRequest{
		RepositoryDir: repository,
		Version:       "v1.2.3",
		OutputDir:     outputDir,
	})
	if err != nil {
		t.Fatalf("Build() error = %v", err)
	}
	if result.CandidateCommit == "" || result.Compiler != "" || len(result.Targets) != 0 || len(result.Artifacts) != 0 {
		t.Fatalf("empty build result = %#v", result)
	}
	if _, err := os.Stat(outputDir); !errors.Is(err, os.ErrNotExist) {
		t.Fatalf("empty build created output directory: %v", err)
	}
}

func TestBuildRegeneratesOwnedOutputsAndPreservesUnrelatedFiles(t *testing.T) {
	const source = `package main
import("fmt";"gitea.maximumdirect.net/eric/ReleaseKit/buildinfo")
func main(){fmt.Println("fixture",buildinfo.Version())}
`
	repository := newBuildConsumer(t, source)
	outputDir := t.TempDir()
	unrelated := filepath.Join(outputDir, "keep.txt")
	if err := os.WriteFile(unrelated, []byte("keep this file"), 0600); err != nil {
		t.Fatal(err)
	}
	request := releasekit.BuildRequest{RepositoryDir: repository, Version: "v1.2.3", Spec: releasekit.BuildSpec{MainPackage: "./cmd/app", BinaryName: "fixture", Targets: []releasekit.Target{{OS: runtime.GOOS, Arch: runtime.GOARCH}}}, OutputDir: outputDir}
	unsafe := request
	unsafe.Spec.BinaryName = "../unsafe"
	if _, err := releasekit.Build(context.Background(), unsafe); err == nil {
		t.Fatal("unsafe binary name accepted")
	}
	first, err := releasekit.Build(context.Background(), request)
	if err != nil {
		t.Fatal(err)
	}
	repeated, err := releasekit.Build(context.Background(), request)
	if err != nil {
		t.Fatal(err)
	}
	if repeated.Artifacts[0].SHA256 != first.Artifacts[0].SHA256 {
		t.Fatal("identical build changed output")
	}
	writeBuildFixture(t, repository, "cmd/app/main.go", source+"\nfunc init(){if len([]byte(buildinfo.Version()))==0 {panic(\"changed build\")}}\n")
	changed, err := releasekit.Build(context.Background(), request)
	if err != nil {
		t.Fatal(err)
	}
	if changed.Artifacts[0].SHA256 == first.Artifacts[0].SHA256 {
		t.Fatal("changed source did not regenerate binary")
	}
	content, err := os.ReadFile(unrelated)
	if err != nil || string(content) != "keep this file" {
		t.Fatalf("unrelated file=%q %v", content, err)
	}
}

func TestBuildReturnsPartialArtifactsAfterTargetFailure(t *testing.T) {
	repository := newBuildConsumer(t, "package main\nfunc main() {}\n")
	result, err := releasekit.Build(context.Background(), releasekit.BuildRequest{
		RepositoryDir: repository,
		Version:       "v1.2.3",
		Spec: releasekit.BuildSpec{
			MainPackage: "./cmd/app",
			BinaryName:  "fixture",
			Targets: []releasekit.Target{
				{OS: runtime.GOOS, Arch: runtime.GOARCH},
				{OS: "invalid-os", Arch: "invalid-arch"},
			},
		},
		OutputDir: filepath.Join(t.TempDir(), "artifacts"),
	})
	if err == nil || len(result.Artifacts) != 1 {
		t.Fatalf("Build() result = %#v, error = %v; want one retained artifact", result, err)
	}
	if _, err := os.Stat(result.Artifacts[0].Path); err != nil {
		t.Fatalf("partial artifact was not retained: %v", err)
	}
}

func TestBuildReportsMissingMainPackage(t *testing.T) {
	repository := newBuildConsumer(t, "package main\nfunc main() {}\n")
	result, err := releasekit.Build(context.Background(), releasekit.BuildRequest{
		RepositoryDir: repository,
		Version:       "v1.2.3",
		Spec: releasekit.BuildSpec{
			MainPackage: "./cmd/missing",
			BinaryName:  "fixture",
			Targets:     []releasekit.Target{{OS: runtime.GOOS, Arch: runtime.GOARCH}},
		},
		OutputDir: filepath.Join(t.TempDir(), "artifacts"),
	})
	if err == nil || !strings.Contains(err.Error(), "cmd/missing") || len(result.Artifacts) != 0 {
		t.Fatalf("Build() result = %#v, error = %v; want missing-package failure", result, err)
	}
}

func TestBuildReportsIncorrectVersionOutputAndRetainsBinary(t *testing.T) {
	repository := newBuildConsumer(t, `package main
import (
	"fmt"
	"os"
)
func main() { if len(os.Args) == 2 && os.Args[1] == "version" { fmt.Println("wrong") } }
`)
	outputDir := filepath.Join(t.TempDir(), "artifacts")
	result, err := releasekit.Build(context.Background(), releasekit.BuildRequest{
		RepositoryDir: repository,
		Version:       "v1.2.3",
		Spec: releasekit.BuildSpec{
			MainPackage: "./cmd/app",
			BinaryName:  "fixture",
			Targets:     []releasekit.Target{{OS: runtime.GOOS, Arch: runtime.GOARCH}},
		},
		OutputDir: outputDir,
	})
	if err == nil || !strings.Contains(err.Error(), "native version output") || len(result.Artifacts) != 1 {
		t.Fatalf("Build() result = %#v, error = %v; want retained-binary smoke failure", result, err)
	}
	if _, err := os.Stat(result.Artifacts[0].Path); err != nil {
		t.Fatalf("built artifact was not retained after smoke failure: %v", err)
	}
}

func TestBuildCancellationReturnsCompletedArtifacts(t *testing.T) {
	repository := newBuildConsumer(t, "package main\nfunc main() {}\n")
	realGo, err := exec.LookPath("go")
	if err != nil {
		t.Fatal(err)
	}
	wrapperDir := t.TempDir()
	wrapper := filepath.Join(wrapperDir, "go")
	callCount := filepath.Join(wrapperDir, "build-count")
	blocked := filepath.Join(wrapperDir, "second-build-started")
	contents := "#!/bin/sh\n" +
		"for argument do\n" +
		"  if [ \"$argument\" = build ]; then\n" +
		"    count=0\n" +
		"    if [ -f \"$RELEASEKIT_BUILD_COUNT\" ]; then count=$(cat \"$RELEASEKIT_BUILD_COUNT\"); fi\n" +
		"    count=$((count + 1))\n" +
		"    printf '%s\\n' \"$count\" > \"$RELEASEKIT_BUILD_COUNT\"\n" +
		"    if [ \"$count\" -eq 2 ]; then : > \"$RELEASEKIT_BUILD_BLOCKED\"; exec sleep 30; fi\n" +
		"  fi\n" +
		"done\n" +
		"exec \"$RELEASEKIT_BUILD_REAL_GO\" \"$@\"\n"
	if err := os.WriteFile(wrapper, []byte(contents), 0o755); err != nil {
		t.Fatal(err)
	}
	t.Setenv("PATH", wrapperDir+string(os.PathListSeparator)+os.Getenv("PATH"))
	t.Setenv("RELEASEKIT_BUILD_COUNT", callCount)
	t.Setenv("RELEASEKIT_BUILD_BLOCKED", blocked)
	t.Setenv("RELEASEKIT_BUILD_REAL_GO", realGo)
	secondTarget := releasekit.Target{OS: "darwin", Arch: "arm64"}
	if secondTarget == (releasekit.Target{OS: runtime.GOOS, Arch: runtime.GOARCH}) {
		secondTarget = releasekit.Target{OS: "linux", Arch: "amd64"}
	}
	ctx, cancel := context.WithCancel(context.Background())
	done := make(chan struct {
		result releasekit.BuildResult
		err    error
	}, 1)
	go func() {
		result, err := releasekit.Build(ctx, releasekit.BuildRequest{
			RepositoryDir: repository,
			Version:       "v1.2.3",
			Spec: releasekit.BuildSpec{
				MainPackage: "./cmd/app",
				BinaryName:  "fixture",
				Targets:     []releasekit.Target{{OS: runtime.GOOS, Arch: runtime.GOARCH}, secondTarget},
			},
			OutputDir: filepath.Join(t.TempDir(), "artifacts"),
		})
		done <- struct {
			result releasekit.BuildResult
			err    error
		}{result: result, err: err}
	}()
	ticker := time.NewTicker(10 * time.Millisecond)
	defer ticker.Stop()
	deadline := time.NewTimer(30 * time.Second)
	defer deadline.Stop()
	for {
		if _, err := os.Stat(blocked); err == nil {
			cancel()
			break
		}
		select {
		case outcome := <-done:
			cancel()
			t.Fatalf("Build() ended before cancellation: result=%#v error=%v", outcome.result, outcome.err)
		case <-deadline.C:
			cancel()
			outcome := <-done
			t.Fatalf("second build did not start: result=%#v error=%v", outcome.result, outcome.err)
		case <-ticker.C:
		}
	}
	outcome := <-done
	if !errors.Is(outcome.err, context.Canceled) || len(outcome.result.Artifacts) != 1 {
		t.Fatalf("canceled build result=%#v error=%v; want one retained artifact", outcome.result, outcome.err)
	}
}

func TestCheckBuildsAfterValidationAndKeepsOutputOutsideWorktree(t *testing.T) {
	repository := newPublishFixture(t)
	prepareCandidateBuild(t, repository.work, `package main
import (
	"fmt"
	"os"
	"gitea.maximumdirect.net/eric/ReleaseKit/buildinfo"
)
func main() { if len(os.Args) == 2 && os.Args[1] == "version" { fmt.Printf("fixture %s\n", buildinfo.Version()) } }
`)
	var validations int
	candidate, err := releasekit.Check(context.Background(), releasekit.ReleaseRequest{
		RepositoryDir: repository.work,
		Product:       "Sample App",
		Version:       "v1.2.3",
		Validate: func(context.Context, releasekit.Candidate) error {
			validations++
			return nil
		},
		Build: &releasekit.BuildSpec{
			MainPackage: "./cmd/app",
			BinaryName:  "fixture",
			Targets:     []releasekit.Target{{OS: runtime.GOOS, Arch: runtime.GOARCH}},
		},
	})
	if err != nil {
		t.Fatalf("Check() error = %v", err)
	}
	if validations != 1 || candidate.Commit != gitText(t, repository.work, "rev-parse", "HEAD") {
		t.Fatalf("candidate = %#v, validation calls = %d", candidate, validations)
	}
	if got := gitText(t, repository.work, "status", "--porcelain"); got != "" {
		t.Fatalf("candidate build dirtied worktree: %s", got)
	}
	if paths, err := filepath.Glob(filepath.Join(filepath.Dir(repository.work), ".releasekit-candidate-build-*")); err != nil || len(paths) != 0 {
		t.Fatalf("temporary candidate output remains: %v, error=%v", paths, err)
	}
}

func TestPublishBuildFailurePreventsTagCreation(t *testing.T) {
	repository := newPublishFixture(t)
	prepareCandidateBuild(t, repository.work, "package main\nfunc main() {}\n")
	var validations int
	result, err := releasekit.Publish(context.Background(), releasekit.ReleaseRequest{
		RepositoryDir: repository.work,
		Product:       "Sample App",
		Version:       "v1.2.3",
		Validate: func(context.Context, releasekit.Candidate) error {
			validations++
			return nil
		},
		Build: &releasekit.BuildSpec{
			MainPackage: "./cmd/missing",
			BinaryName:  "fixture",
			Targets:     []releasekit.Target{{OS: runtime.GOOS, Arch: runtime.GOARCH}},
		},
	})
	if err == nil || !strings.Contains(err.Error(), "build candidate") || result.TagObject != "" {
		t.Fatalf("Publish() result=%#v error=%v; want build failure before tag creation", result, err)
	}
	if validations != 1 {
		t.Fatalf("validation calls = %d, want 1", validations)
	}
	if _, err := exec.Command("git", "--git-dir", repository.bare, "show-ref", "--verify", "--quiet", "refs/tags/v1.2.3").CombinedOutput(); err == nil {
		t.Fatal("build failure published the release tag")
	}
	if _, err := exec.Command("git", "-C", repository.work, "show-ref", "--verify", "--quiet", "refs/tags/v1.2.3").CombinedOutput(); err == nil {
		t.Fatal("build failure created a local release tag")
	}
}

func newBuildConsumer(t *testing.T, mainSource string) string {
	t.Helper()
	repository, err := os.MkdirTemp("", "releasekit-build-consumer-")
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { _ = os.RemoveAll(repository) })
	root, err := filepath.Abs(".")
	if err != nil {
		t.Fatal(err)
	}
	module := fmt.Sprintf("module example.com/buildfixture\n\ngo 1.25.0\n\nrequire gitea.maximumdirect.net/eric/ReleaseKit v0.0.0\n\nreplace gitea.maximumdirect.net/eric/ReleaseKit => %s\n", filepath.ToSlash(root))
	writeBuildFixture(t, repository, "go.mod", module)
	writeBuildFixture(t, repository, "cmd/app/main.go", mainSource)
	buildGit(t, repository, "init", "--initial-branch=main")
	buildGit(t, repository, "config", "user.name", "ReleaseKit Build Test")
	buildGit(t, repository, "config", "user.email", "releasekit-build@example.test")
	buildGit(t, repository, "add", "--all")
	buildGit(t, repository, "commit", "-m", "build fixture")
	return repository
}

func prepareCandidateBuild(t *testing.T, repository, mainSource string) {
	t.Helper()
	root, err := filepath.Abs(".")
	if err != nil {
		t.Fatal(err)
	}
	module := fmt.Sprintf("module example.com/candidatebuild\n\ngo 1.25.0\n\nrequire gitea.maximumdirect.net/eric/ReleaseKit v0.0.0\n\nreplace gitea.maximumdirect.net/eric/ReleaseKit => %s\n", filepath.ToSlash(root))
	writeFile(t, repository, "go.mod", module)
	writeFile(t, repository, ".gitignore", "dist/\n")
	writeFile(t, repository, "cmd/app/main.go", mainSource)
	gitRun(t, repository, "add", "--all")
	gitRun(t, repository, "commit", "-m", "add buildable candidate")
	gitRun(t, repository, "config", "remote.origin.mirror", "false")
	gitRun(t, repository, "push", "origin", "HEAD:refs/heads/main")
}

func writeBuildFixture(t *testing.T, directory, name, contents string) {
	t.Helper()
	path := filepath.Join(directory, filepath.FromSlash(name))
	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(path, []byte(contents), 0o600); err != nil {
		t.Fatal(err)
	}
}

func buildGit(t *testing.T, directory string, args ...string) string {
	t.Helper()
	command := exec.Command("git", append([]string{"-C", directory}, args...)...)
	output, err := command.CombinedOutput()
	if err != nil {
		t.Fatalf("git %v: %v\n%s", args, err, output)
	}
	return strings.TrimSpace(string(output))
}

func TestBuildSourceEligibilitySurvivesLaterCheckoutCleanup(t *testing.T) {
	const source = `package main
import("fmt";"os";"gitea.maximumdirect.net/eric/ReleaseKit/buildinfo")
func main(){ if len(os.Args)>1 && os.Args[1]=="version" {fmt.Println("fixture",buildinfo.Version())} }
`
	for _, mode := range []string{"clean", "dirty before build", "changed during build"} {
		t.Run(mode, func(t *testing.T) {
			repository := newBuildConsumer(t, source)
			writeBuildFixture(t, repository, "docs/releases/v1.2.3.md", "# Fixture v1.2.3\n")
			buildGit(t, repository, "add", "--all")
			buildGit(t, repository, "commit", "-m", "release note")
			buildGit(t, repository, "tag", "v1.2.3")
			mutate := func() { writeBuildFixture(t, repository, "cmd/app/main.go", source+"\n// local change\n") }
			if mode == "dirty before build" {
				mutate()
			}
			var writer *sourceChangeWriter
			request := releasekit.BuildRequest{RepositoryDir: repository, Version: "v1.2.3", Spec: releasekit.BuildSpec{MainPackage: "./cmd/app", BinaryName: "fixture", Targets: []releasekit.Target{{OS: runtime.GOOS, Arch: runtime.GOARCH}}}, OutputDir: t.TempDir()}
			if mode == "changed during build" {
				writer = &sourceChangeWriter{change: mutate}
				request.Output = writer
			}
			result, err := releasekit.Build(context.Background(), request)
			if err != nil {
				t.Fatal(err)
			}
			if result.SourceVerified != (mode == "clean") {
				t.Fatalf("source eligibility=%t for %s", result.SourceVerified, mode)
			}
			if mode == "clean" {
				return
			}
			buildGit(t, repository, "restore", "cmd/app/main.go")
			delivered, err := releasekit.Deliver(context.Background(), releasekit.DeliveryRequest{RepositoryDir: repository, Product: "Fixture", Version: "v1.2.3", Build: &result})
			if err == nil || !strings.Contains(err.Error(), "build source") || delivered.State != releasekit.DeliveryNotAttempted {
				t.Fatalf("dirty source delivered: %#v %v", delivered, err)
			}
		})
	}
}

type sourceChangeWriter struct{ change func() }

func (w *sourceChangeWriter) Write(p []byte) (int, error) {
	if w.change != nil {
		w.change()
		w.change = nil
	}
	return len(p), nil
}