package publish

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

func TestRecoveryAlreadyCanceledDiscovery(t *testing.T) {
	for _, override := range []string{"", "relative"} {
		ctx, cancel := context.WithCancel(t.Context())
		cancel()
		result, err := ListAttempts(ctx, t.TempDir(), override)
		requireCanceledRecovery(t, err)
		if len(result.Attempts) != 0 {
			t.Fatalf("unexpected attempts: %#v", result)
		}
	}
}

func requireCanceledRecovery(t *testing.T, err error) {
	t.Helper()
	var recovery *RecoveryError
	if !errors.As(err, &recovery) || recovery.Kind != "canceled" || !errors.Is(err, context.Canceled) {
		t.Fatalf("cancellation = %v; want canceled kind and cause", err)
	}
}

func TestRecoveryCancelsActiveGitOperations(t *testing.T) {
	if runtime.GOOS == "windows" {
		t.Skip("fixture uses a POSIX Git launcher")
	}
	tests := []struct {
		name, command string
		run           func(context.Context, string) error
	}{
		{"default discovery root", "--show-toplevel", func(ctx context.Context, repo string) error { _, err := ListAttempts(ctx, repo, ""); return err }},
		{"relative discovery root", "--show-toplevel", func(ctx context.Context, repo string) error { _, err := ListAttempts(ctx, repo, "records"); return err }},
		{"default discovery metadata", "--git-common-dir", func(ctx context.Context, repo string) error { _, err := ListAttempts(ctx, repo, ""); return err }},
		{"record metadata", "--git-common-dir", func(ctx context.Context, repo string) error {
			_, err := SaveEvidence(ctx, repo, "", Evidence{})
			return err
		}},
		{"record ignore guard", "check-ignore", func(ctx context.Context, repo string) error {
			_, err := SaveEvidence(ctx, repo, "records", Evidence{})
			return err
		}},
		{"publication metadata", "--git-common-dir", func(ctx context.Context, repo string) error {
			result, err := Publish(ctx, Request{RepositoryDir: repo, Product: "Sample", Version: "v1.2.3"})
			if !errors.Is(result.RecordError, context.Canceled) {
				return fmt.Errorf("record cancellation lost: %v", result.RecordError)
			}
			return err
		}},
		{"tag validation", "check-ref-format", func(ctx context.Context, repo string) error {
			_, err := Reconcile(ctx, Evidence{RepositoryDir: repo, Endpoint: repo, Tag: "v1.2.3"})
			return err
		}},
		{"tag query", "ls-remote", func(ctx context.Context, repo string) error {
			_, err := Reconcile(ctx, Evidence{RepositoryDir: repo, Endpoint: repo, Tag: "v1.2.3"})
			return err
		}},
	}
	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			repo := recordRepo(t)
			if test.name == "publication metadata" {
				if err := os.WriteFile(filepath.Join(repo, "go.mod"), []byte("module example.com/sample\n\ngo 1.26.0\n"), 0600); err != nil {
					t.Fatal(err)
				}
				if err := os.MkdirAll(filepath.Join(repo, "docs", "releases"), 0700); err != nil {
					t.Fatal(err)
				}
				if err := os.WriteFile(filepath.Join(repo, "docs", "releases", "v1.2.3.md"), []byte("# Sample v1.2.3\n\nChanges.\n"), 0600); err != nil {
					t.Fatal(err)
				}
				recordGit(t, repo, "checkout", "-B", "main")
				recordGit(t, repo, "add", ".")
				recordGit(t, repo, "commit", "-qm", "Release candidate")
			}
			realGit, err := exec.LookPath("git")
			if err != nil {
				t.Fatal(err)
			}
			bin := t.TempDir()
			ready := filepath.Join(t.TempDir(), "ready")
			quote := func(s string) string { return "'" + strings.ReplaceAll(s, "'", "'\"'\"'") + "'" }
			script := "#!/bin/sh\nfor arg in \"$@\"; do\n if [ \"$arg\" = " + quote(test.command) + " ]; then\n echo $$ > " + quote(ready) + "\n exec sleep 600\n fi\ndone\nexec " + quote(realGit) + " \"$@\"\n"
			if err := os.WriteFile(filepath.Join(bin, "git"), []byte(script), 0755); err != nil {
				t.Fatal(err)
			}
			t.Setenv("PATH", bin+string(os.PathListSeparator)+os.Getenv("PATH"))
			ctx, cancel := context.WithCancel(t.Context())
			defer cancel()
			done := make(chan error, 1)
			go func() { done <- test.run(ctx, repo) }()
			// Synchronize cancellation with the intercepted operation, rather than timing its start.
			ticker := time.NewTicker(5 * time.Millisecond)
			defer ticker.Stop()
			timeout := time.NewTimer(10 * time.Second)
			defer timeout.Stop()
			var pid int
		waiting:
			for {
				select {
				case err := <-done:
					t.Fatalf("operation finished before interception: %v", err)
				case <-timeout.C:
					t.Fatal("Git operation was never intercepted")
				case <-ticker.C:
					data, err := os.ReadFile(ready)
					if err == nil {
						pid, err = strconv.Atoi(strings.TrimSpace(string(data)))
						if err == nil {
							break waiting
						}
					}
				}
			}
			cancel()
			select {
			case err := <-done:
				if !errors.Is(err, context.Canceled) {
					t.Fatalf("lost context cause: %v", err)
				}
				if strings.Contains(test.name, "discovery") || test.command == "check-ref-format" || test.command == "ls-remote" {
					requireCanceledRecovery(t, err)
				}
			case <-time.After(5 * time.Second):
				process, _ := os.FindProcess(pid)
				if process != nil {
					_ = process.Kill()
				}
				<-done
				t.Fatal("cancellation did not stop the Git operation")
			}
		})
	}
}