package tools

import (
	"errors"
	"os/exec"
	"runtime"
	"strings"
	"testing"
)

func TestDetectShellRuntimePrefersPowerShellSevenOnWindows(t *testing.T) {
	lookPath := func(name string) (string, error) {
		if name == "pwsh.exe" {
			return `C:\Program Files\PowerShell\7\pwsh.exe`, nil
		}
		return "", errors.New("not found")
	}
	shell := detectShellRuntimeWithLookup("windows", lookPath, func(string) string { return "" })
	if shell.Kind != shellKindPowerShell || !strings.HasSuffix(strings.ToLower(shell.Executable), `\pwsh.exe`) {
		t.Fatalf("shell = %#v, want PowerShell 7", shell)
	}
}

func TestDetectShellRuntimeFallsBackThroughWindowsPowerShellToCmd(t *testing.T) {
	t.Run("windows powershell", func(t *testing.T) {
		lookPath := func(name string) (string, error) {
			if name == "powershell.exe" {
				return `C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe`, nil
			}
			return "", errors.New("not found")
		}
		shell := detectShellRuntimeWithLookup("windows", lookPath, func(string) string { return "" })
		if shell.Kind != shellKindPowerShell || !strings.HasSuffix(strings.ToLower(shell.Executable), `\powershell.exe`) {
			t.Fatalf("shell = %#v, want Windows PowerShell", shell)
		}
	})

	t.Run("cmd", func(t *testing.T) {
		shell := detectShellRuntimeWithLookup(
			"windows",
			func(string) (string, error) { return "", errors.New("not found") },
			func(string) string { return "" },
		)
		if shell.Kind != shellKindCmd || shell.Executable != "cmd.exe" {
			t.Fatalf("shell = %#v, want cmd.exe fallback", shell)
		}
	})
}

func TestDetectShellRuntimeSkipsUnusablePowerShell(t *testing.T) {
	lookPath := func(name string) (string, error) {
		switch name {
		case "pwsh.exe":
			return `C:\broken\pwsh.exe`, nil
		case "powershell.exe":
			return `C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe`, nil
		default:
			return "", errors.New("not found")
		}
	}
	shell := detectShellRuntimeWithProbe(
		"windows",
		lookPath,
		func(string) string { return "" },
		func(path string) bool { return !strings.Contains(path, `\broken\`) },
	)
	if shell.Kind != shellKindPowerShell || strings.Contains(shell.Executable, `\broken\`) {
		t.Fatalf("shell = %#v, want usable Windows PowerShell fallback", shell)
	}
}

func TestPowerShellArgumentsDisableProfilesAndRequestUTF8(t *testing.T) {
	shell := shellRuntime{GOOS: "windows", Executable: "pwsh.exe", Syntax: "PowerShell", Kind: shellKindPowerShell}
	args := shell.arguments("Write-Output 'hello'")
	joined := strings.Join(args, "\n")
	for _, want := range []string{
		"-NoLogo",
		"-NoProfile",
		"-Command",
		windowsPowerShellUTF8Prefix,
		"$ErrorActionPreference = 'Stop'",
		"Write-Output 'hello'",
		"exit $LASTEXITCODE",
	} {
		if !strings.Contains(joined, want) {
			t.Fatalf("PowerShell args missing %q: %#v", want, args)
		}
	}
	script := args[len(args)-1]
	preferenceIndex := strings.Index(script, "$ErrorActionPreference")
	commandIndex := strings.Index(script, "Write-Output 'hello'")
	exitIndex := strings.Index(script, "exit $LASTEXITCODE")
	if preferenceIndex < 0 || commandIndex <= preferenceIndex || exitIndex <= commandIndex {
		t.Fatalf("PowerShell failure handling is not ordered around the command: %q", script)
	}
}

func TestWindowsPowerShellArgumentsPropagateFailures(t *testing.T) {
	if runtime.GOOS != "windows" {
		t.Skip("Windows PowerShell integration test")
	}
	executable, err := exec.LookPath("powershell.exe")
	if err != nil {
		t.Skipf("Windows PowerShell unavailable: %v", err)
	}
	shell := shellRuntime{
		GOOS:       "windows",
		Executable: executable,
		Syntax:     "PowerShell",
		Kind:       shellKindPowerShell,
	}

	t.Run("native exit code after cmdlet", func(t *testing.T) {
		command := exec.Command(executable, shell.arguments("cmd /c exit 5; Write-Output done")...)
		output, err := command.CombinedOutput()
		var exitErr *exec.ExitError
		if !errors.As(err, &exitErr) || exitErr.ExitCode() != 5 {
			t.Fatalf("exit = %v, output = %q; want exact native exit code 5", err, output)
		}
		if !strings.Contains(string(output), "done") {
			t.Fatalf("output = %q, want command output before propagated failure", output)
		}
	})

	t.Run("cmdlet error stops script", func(t *testing.T) {
		missing := strings.ReplaceAll(t.TempDir()+`\missing`, `'`, `''`)
		commandText := "Get-Item -LiteralPath '" + missing + "'; Write-Output after"
		command := exec.Command(executable, shell.arguments(commandText)...)
		output, err := command.CombinedOutput()
		if err == nil {
			t.Fatalf("cmdlet failure reported success: %q", output)
		}
		if strings.Contains(string(output), "after") {
			t.Fatalf("script continued after cmdlet failure: %q", output)
		}
	})
}

func TestWindowsPowerShellGuidanceAvoidsUnsupportedChainOperators(t *testing.T) {
	shell := shellRuntime{
		GOOS:       "windows",
		Executable: `C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe`,
		Syntax:     "PowerShell",
		Kind:       shellKindPowerShell,
	}
	for _, guidance := range []string{
		shellGuidanceForRuntime(shell),
		hostShellEnvironmentGuidanceForRuntime(shell),
	} {
		for _, want := range []string{"Windows PowerShell 5.1", "&&", "||", "if ($?)"} {
			if !strings.Contains(guidance, want) {
				t.Fatalf("legacy PowerShell guidance missing %q: %q", want, guidance)
			}
		}
	}
}

func TestWindowsPowerShellCommandIssueFlagsUnsupportedChainOperators(t *testing.T) {
	legacy := shellRuntime{
		GOOS:       "windows",
		Executable: "powershell.exe",
		Syntax:     "PowerShell",
		Kind:       shellKindPowerShell,
	}
	for _, command := range []string{
		"Write-Output one && Write-Output two",
		"Write-Output one || Write-Output two",
	} {
		issue := detectShellCommandIssueForRuntime(command, legacy)
		if issue == nil || issue.Kind != "windows_powershell_version" {
			t.Fatalf("legacy PowerShell command %q issue = %#v, want version issue", command, issue)
		}
	}
	for _, command := range []string{
		`Write-Output "one && two"`,
		"Write-Output 'one || two'",
		"Write-Output one `&`& Write-Output two",
	} {
		if issue := detectShellCommandIssueForRuntime(command, legacy); issue != nil {
			t.Fatalf("literal legacy PowerShell operators in %q produced issue %#v", command, issue)
		}
	}

	modern := shellRuntime{GOOS: "windows", Executable: "pwsh.exe", Syntax: "PowerShell", Kind: shellKindPowerShell}
	if issue := detectShellCommandIssueForRuntime("Write-Output one && Write-Output two", modern); issue != nil {
		t.Fatalf("PowerShell 7 chain operator produced issue %#v", issue)
	}
}

func TestPowerShellCommandIssueAllowsAliasesAndBlocksMsysExecutables(t *testing.T) {
	shell := shellRuntime{GOOS: "windows", Executable: "pwsh.exe", Syntax: "PowerShell", Kind: shellKindPowerShell}
	for _, command := range []string{
		`ls -Force`,
		`cat README.md`,
		`Get-ChildItem | Select-Object -First 10`,
		`Write-Output 'grep README.md; head file.txt'`,
		`Write-Output 'cd /tmp'`,
	} {
		if issue := detectShellCommandIssueForRuntime(command, shell); issue != nil {
			t.Fatalf("PowerShell-native command %q was blocked: %#v", command, issue)
		}
	}
	for _, command := range []string{
		`grep README.md`,
		`Get-Content README.md | head -10`,
		`cat.exe README.md`,
		`bash -lc "make test"`,
		`Write-Output ok; sed -n '1,5p' README.md`,
	} {
		if issue := detectShellCommandIssueForRuntime(command, shell); issue == nil || issue.Kind != windowsMsysSandboxKind {
			t.Fatalf("MSYS-prone command %q was not blocked: %#v", command, issue)
		}
	}
}

func TestDetectShellCommandIssueFlagsMsysBinaryPaths(t *testing.T) {
	for _, command := range []string{
		`for /F %i in ('whoami') do echo %i | "C:\Program Files\Git\usr\bin\head.exe" -1`,
		`C:\Git\usr\bin\grep.exe pattern file.txt`,
	} {
		issue := detectShellCommandIssue(command, "windows")
		if issue == nil {
			t.Fatalf("expected MSYS path issue for %q", command)
		}
		if issue.Kind != "windows_msys_sandbox" {
			t.Fatalf("expected windows_msys_sandbox kind, got %q", issue.Kind)
		}
		if !strings.Contains(issue.Suggestion, "require_escalated") {
			t.Fatalf("expected escalation guidance, got %#v", issue)
		}
	}
}

func TestDetectShellCommandIssueFlagsStandaloneCat(t *testing.T) {
	issue := detectShellCommandIssue(`cat README.md`, "windows")
	if issue == nil || issue.Kind != "windows_msys_sandbox" {
		t.Fatalf("expected MSYS sandbox issue for cat, got %#v", issue)
	}
}

// TestDetectShellCommandIssueFlagsShells covers bash/sh invocations: every
// executable a bare `bash` resolves to on Windows fails under the restricted
// token (Git-for-Windows MSYS bash dies during runtime init; the System32 WSL
// launcher is denied its WSL service connection), so both names are blocked
// upfront like the MSYS coreutils.
func TestDetectShellCommandIssueFlagsShells(t *testing.T) {
	for _, command := range []string{
		`bash -c "make test"`,
		`bash.exe -lc ls`,
		`sh -c "echo hi"`,
		`sh.exe -c "echo hi"`,
		`git status && bash -c "echo hi"`,
	} {
		issue := detectShellCommandIssue(command, "windows")
		if issue == nil || issue.Kind != "windows_msys_sandbox" {
			t.Fatalf("expected windows_msys_sandbox for %q, got %#v", command, issue)
		}
	}

	// Shell names inside quoted argument text are not invocations.
	for _, command := range []string{
		`git commit -m "bash fails under the sandbox"`,
		`gh pr comment --body "run sh -c manually"`,
	} {
		if issue := detectShellCommandIssue(command, "windows"); issue != nil {
			t.Fatalf("expected quoted shell mention to pass for %q, got %#v", command, issue)
		}
	}
}

func TestDetectShellOutputIssueFlagsMsysCreateFileMappingError(t *testing.T) {
	output := `0 [main] head (3568) C:\Program Files\Git\usr\bin\head.exe: *** fatal error - CreateFileMapping S-1-5-21-3149109338-1484423945-518236903-1001.1, Win32 error 5.  Terminating.`
	issue := detectShellOutputIssue(output, "windows")
	if issue == nil || issue.Kind != "windows_msys_sandbox" {
		t.Fatalf("expected MSYS output issue, got %#v", issue)
	}
	if !strings.Contains(issue.Suggestion, "require_escalated") {
		t.Fatalf("expected escalation guidance, got %#v", issue)
	}
}

func TestDetectShellOutputIssueFlagsMsysSignalPipeError(t *testing.T) {
	output := `0 [main] head (39684) cygheap_user::init: NtSetInformationToken (TokenDefaultDacl), 0xC0000022
648 [main] head (39684) C:\Program Files\Git\usr\bin\head.exe: *** fatal error - couldn't create signal pipe, Win32 error 5`
	issue := detectShellOutputIssue(output, "windows")
	if issue == nil || issue.Kind != "windows_msys_sandbox" {
		t.Fatalf("expected MSYS output issue, got %#v", issue)
	}
}

func TestDetectShellOutputIssueFlagsMsysTerminatingWithMsysMarker(t *testing.T) {
	output := `1 [main] tail (4321) tail: *** MapViewOfFileEx failed, Win32 error 5.  Terminating.`
	issue := detectShellOutputIssue(output, "windows")
	if issue == nil || issue.Kind != "windows_msys_sandbox" {
		t.Fatalf("expected MSYS output issue, got %#v", issue)
	}
}

// TestDetectShellOutputIssueFlagsWslServiceDenied pins detection of the WSL
// bash launcher's failure under the restricted token. The launcher writes
// UTF-16LE to a piped stderr, so the captured text carries a NUL byte after
// every ASCII character; the fixture reproduces that shape.
func TestDetectShellOutputIssueFlagsWslServiceDenied(t *testing.T) {
	var utf16ish strings.Builder
	for _, r := range "Access is denied.\r\nError code: Bash/Service/CreateInstance/E_ACCESSDENIED\r\n" {
		utf16ish.WriteRune(r)
		utf16ish.WriteByte(0)
	}
	issue := detectShellOutputIssue(utf16ish.String(), "windows")
	if issue == nil || issue.Kind != "windows_msys_sandbox" {
		t.Fatalf("expected WSL service-denied output issue, got %#v", issue)
	}
	if !strings.Contains(issue.Message, "WSL") {
		t.Fatalf("expected WSL-specific message, got %#v", issue)
	}
}

func TestDetectShellOutputIssueIgnoresNonMsysWin32Error5(t *testing.T) {
	output := `myapp.exe: unable to open service handle, Win32 error 5 (access denied). Terminating worker.`
	issue := detectShellOutputIssue(output, "windows")
	if issue != nil {
		t.Fatalf("expected no issue for non-MSYS access-denied output, got %#v", issue)
	}
}

func TestShellIssueBlockResultMsysCommand(t *testing.T) {
	result := shellIssueBlockResult(*detectShellCommandIssue(`cat README.md`, "windows"))
	if result.Status != StatusError {
		t.Fatalf("status = %q, want error", result.Status)
	}
	for _, want := range []string{"[zero] shell issue:", "MSYS/Cygwin", "grep", "read_file", "require_escalated"} {
		if !strings.Contains(result.Output, want) {
			t.Fatalf("expected %q in blocked output, got %q", want, result.Output)
		}
	}
	if result.Meta["shell_issue"] != "windows_msys_sandbox" {
		t.Fatalf("meta shell_issue = %q", result.Meta["shell_issue"])
	}
}

func TestMsysProneCommandName(t *testing.T) {
	if !MsysProneCommandName("HEAD") || !MsysProneCommandName("bash") || MsysProneCommandName("echo") {
		t.Fatalf("unexpected MsysProneCommandName results")
	}
}

// TestDetectShellCommandIssueFlagsExprAndLsConsistently guards against the
// preflight regex list drifting from the canonical windowsMsysProneNames set
// (both listed expr and ls as MSYS-prone, but the old regex alternations
// omitted expr entirely and let ls hit the older windows_shell_syntax branch
// first, so it never got MSYS-kind guidance).
func TestDetectShellCommandIssueFlagsExprAndLsConsistently(t *testing.T) {
	for _, command := range []string{
		`expr 1 + 1`,
		`expr.exe 1 + 1`,
		`ls -la`,
		`ls`,
	} {
		issue := detectShellCommandIssue(command, "windows")
		if issue == nil || issue.Kind != windowsMsysSandboxKind {
			t.Fatalf("expected windows_msys_sandbox for %q, got %#v", command, issue)
		}
	}
}

// TestDetectShellCommandIssueIgnoresQuotedMsysMentions guards against
// treating an MSYS-prone name that only appears inside a quoted argument
// (e.g. a commit message, a PR comment body, or a doc string discussing the
// command) as an actual invocation. The preflight check must anchor on the
// first word of each command segment, not scan the raw text anywhere.
func TestDetectShellCommandIssueIgnoresQuotedMsysMentions(t *testing.T) {
	for _, command := range []string{
		`git commit -m "fix head.exe crash"`,
		`gh pr comment --body "grep.exe fails under MSYS"`,
		`echo "log | head is broken on windows"`,
		`git commit -m "note: | head does not work here"`,
	} {
		if issue := detectShellCommandIssue(command, "windows"); issue != nil {
			t.Fatalf("expected quoted MSYS mention to pass for %q, got %#v", command, issue)
		}
	}

	// A real invocation alongside quoted text must still be caught.
	if issue := detectShellCommandIssue(`echo "not a real command" && head file.txt`, "windows"); issue == nil || issue.Kind != windowsMsysSandboxKind {
		t.Fatalf("expected real head invocation to still be flagged, got %#v", issue)
	}
}

// TestDetectShellCommandIssueIgnoresQuotedMsysPathMentions guards the
// explicit MSYS-binary-path check the same way as the coreutil-name check:
// a full usr\bin\ path that only appears inside a quoted argument (e.g. a
// commit message describing the failure) must not be treated as an
// invocation, since the path check is now anchored to the first word of each
// command segment rather than scanned across the raw command text.
func TestDetectShellCommandIssueIgnoresQuotedMsysPathMentions(t *testing.T) {
	for _, command := range []string{
		`git commit -m "C:\Program Files\Git\usr\bin\head.exe fails"`,
		`gh pr comment --body "C:\Git\usr\bin\grep.exe is blocked"`,
	} {
		if issue := detectShellCommandIssue(command, "windows"); issue != nil {
			t.Fatalf("expected quoted MSYS path mention to pass for %q, got %#v", command, issue)
		}
	}

	// A real invocation by full path must still be caught.
	if issue := detectShellCommandIssue(`C:\Git\usr\bin\grep.exe pattern file.txt`, "windows"); issue == nil || issue.Kind != windowsMsysSandboxKind {
		t.Fatalf("expected real MSYS path invocation to still be flagged, got %#v", issue)
	}
}

// TestDetectShellCommandIssueRespectsCaretEscapedOperators guards against
// misreading cmd.exe's ^ escape character: `echo ^| head` prints the pipe and
// "head" as literal text (the caret escapes the pipe so it never splits into
// a separate `head` invocation), and `echo foo; head` is a single `echo`
// command with literal arguments since cmd.exe (unlike bash) does not treat
// ; as a statement separator.
func TestDetectShellCommandIssueRespectsCaretEscapedOperators(t *testing.T) {
	for _, command := range []string{
		`echo ^| head`,
		`echo ^& head`,
		`echo foo; head`,
	} {
		if issue := detectShellCommandIssue(command, "windows"); issue != nil {
			t.Fatalf("expected no issue for %q, got %#v", command, issue)
		}
	}

	// An unescaped pipe must still split into a real head invocation.
	if issue := detectShellCommandIssue(`echo foo | head`, "windows"); issue == nil || issue.Kind != windowsMsysSandboxKind {
		t.Fatalf("expected real head invocation to still be flagged, got %#v", issue)
	}
}

// TestDetectShellCommandIssueFlagsRedirectionAttachedToCommand guards against
// firstCommandWord treating cmd.exe redirection operators as part of the
// command name. cmd.exe accepts redirection with no separating space
// (head>out.txt, cat<in.txt), so splitting only on whitespace would return
// "head>out.txt" as one word and miss the invoked command entirely.
func TestDetectShellCommandIssueFlagsRedirectionAttachedToCommand(t *testing.T) {
	for _, command := range []string{
		`some-command | head>out.txt`,
		`cat<in.txt`,
		`grep>matches.txt pattern`,
	} {
		issue := detectShellCommandIssue(command, "windows")
		if issue == nil || issue.Kind != windowsMsysSandboxKind {
			t.Fatalf("expected windows_msys_sandbox for %q, got %#v", command, issue)
		}
	}
}

// TestDetectShellOutputIssueSignatureOmitsCommandText documents, at the type
// level, that detectShellOutputIssue can no longer take the command line as
// evidence: it only accepts the real output. Harmless output must not be
// flagged, and output that genuinely carries the MSYS failure markers must
// still be flagged.
func TestDetectShellOutputIssueSignatureOmitsCommandText(t *testing.T) {
	if issue := detectShellOutputIssue("hello from bash", "windows"); issue != nil {
		t.Fatalf("expected no issue for harmless output, got %#v", issue)
	}
	output := `0 [main] head (3568) C:\Program Files\Git\usr\bin\head.exe: *** fatal error - CreateFileMapping ..., Win32 error 5.  Terminating.`
	if issue := detectShellOutputIssue(output, "windows"); issue == nil || issue.Kind != windowsMsysSandboxKind {
		t.Fatalf("expected real MSYS output to still be flagged, got %#v", issue)
	}
}