package executor

import (
	"bytes"
	"context"
	"errors"
	"io"
	"log/slog"
	"os"
	"path/filepath"
	"strings"
	"testing"

	"github.com/thepeterstone/claudomator/internal/storage"
	"github.com/thepeterstone/claudomator/internal/task"
)

func TestGeminiRunner_BuildArgs_BasicTask(t *testing.T) {
	r := &GeminiRunner{}
	tk := &task.Task{
		Agent: task.AgentConfig{
			Type:         "gemini",
			Instructions: "fix the bug",
			Model:        "gemini-2.5-flash-lite",
			SkipPlanning: true,
		},
	}

	args := r.buildArgs(tk, &storage.Execution{ID: "test-exec"}, "/tmp/q.json")

	// Gemini CLI: instructions passed via -p for non-interactive mode
	if len(args) < 2 || args[0] != "-p" || args[1] != "fix the bug" {
		t.Errorf("expected -p <instructions> as first args, got: %v", args)
	}

	argMap := make(map[string]bool)
	for _, a := range args {
		argMap[a] = true
	}
	for _, want := range []string{"--output-format", "stream-json", "--model", "gemini-2.5-flash-lite"} {
		if !argMap[want] {
			t.Errorf("missing arg %q in %v", want, args)
		}
	}
}

func TestGeminiRunner_BuildArgs_PreamblePrepended(t *testing.T) {
	r := &GeminiRunner{}
	tk := &task.Task{
		Agent: task.AgentConfig{
			Type:         "gemini",
			Instructions: "fix the bug",
			SkipPlanning: false,
		},
	}

	args := r.buildArgs(tk, &storage.Execution{ID: "test-exec"}, "/tmp/q.json")

	if len(args) < 2 || args[0] != "-p" {
		t.Fatalf("expected -p <instructions> as first args, got: %v", args)
	}
	if !strings.HasPrefix(args[1], planningPreamble) {
		t.Errorf("instructions should start with planning preamble")
	}
	if !strings.HasSuffix(args[1], "fix the bug") {
		t.Errorf("instructions should end with original instructions")
	}
}

func TestGeminiRunner_BuildArgs_IncludesYolo(t *testing.T) {
	r := &GeminiRunner{}
	tk := &task.Task{
		Agent: task.AgentConfig{
			Type:         "gemini",
			Instructions: "write a doc",
			SkipPlanning: true,
		},
	}
	args := r.buildArgs(tk, &storage.Execution{ID: "test-exec"}, "/tmp/q.json")
	argMap := make(map[string]bool)
	for _, a := range args {
		argMap[a] = true
	}
	if !argMap["--yolo"] {
		t.Errorf("expected --yolo in gemini args (enables all tools); got: %v", args)
	}
}

func TestGeminiRunner_BuildArgs_IncludesPromptFlag(t *testing.T) {
	r := &GeminiRunner{}
	tk := &task.Task{
		Agent: task.AgentConfig{
			Type:         "gemini",
			Instructions: "do the thing",
			SkipPlanning: true,
		},
	}
	args := r.buildArgs(tk, &storage.Execution{ID: "test-exec"}, "/tmp/q.json")
	// Instructions must be passed via -p/--prompt for non-interactive headless mode,
	// not as a bare positional (which starts interactive mode).
	found := false
	for i, a := range args {
		if (a == "-p" || a == "--prompt") && i+1 < len(args) && args[i+1] == "do the thing" {
			found = true
			break
		}
	}
	if !found {
		t.Errorf("expected instructions passed via -p/--prompt flag; got: %v", args)
	}
}

func TestGeminiRunner_Run_InaccessibleProjectDir_ReturnsError(t *testing.T) {
	r := &GeminiRunner{
		BinaryPath: "true", // would succeed if it ran
		Logger:     slog.New(slog.NewTextHandler(io.Discard, nil)),
		LogDir:     t.TempDir(),
	}
	tk := &task.Task{
		Agent: task.AgentConfig{
			Type:         "gemini",
			ProjectDir:   "/nonexistent/path/does/not/exist",
			SkipPlanning: true,
		},
	}
	exec := &storage.Execution{ID: "test-exec"}

	err := r.Run(context.Background(), tk, exec)

	if err == nil {
		t.Fatal("expected error for inaccessible project_dir, got nil")
	}
	if !strings.Contains(err.Error(), "project_dir") {
		t.Errorf("expected 'project_dir' in error, got: %v", err)
	}
}

func TestGeminiRunner_BinaryPath_Default(t *testing.T) {
	r := &GeminiRunner{}
	if r.binaryPath() != "gemini" {
		t.Errorf("want 'gemini', got %q", r.binaryPath())
	}
}

func TestGeminiRunner_BinaryPath_Custom(t *testing.T) {
	r := &GeminiRunner{BinaryPath: "/usr/local/bin/gemini"}
	if r.binaryPath() != "/usr/local/bin/gemini" {
		t.Errorf("want custom path, got %q", r.binaryPath())
	}
}


func TestParseGeminiStream_ParsesStructuredOutput(t *testing.T) {
	// Simulate a stream-json input with various message types, including a result with error and cost.
	input := streamLine(`{"type":"content_block_start","content_block":{"text":"Hello,"}}`) +
		streamLine(`{"type":"content_block_delta","content_block":{"text":" World!"}}`) +
		streamLine(`{"type":"content_block_end"}`) +
		streamLine(`{"type":"result","subtype":"error_during_execution","is_error":true,"result":"something went wrong","total_cost_usd":0.123}`)

	reader := strings.NewReader(input)
	var writer bytes.Buffer // To capture what's written to the output log
	logger := slog.New(slog.NewTextHandler(io.Discard, nil))

	cost, err := parseGeminiStream(reader, &writer, logger)

	if err == nil {
		t.Errorf("expected an error, got nil")
	}
	if !strings.Contains(err.Error(), "something went wrong") {
		t.Errorf("expected error message to contain 'something went wrong', got: %v", err)
	}

	if cost != 0.123 {
		t.Errorf("expected cost 0.123, got %f", cost)
	}

	// Verify that the writer received the content (even if parseGeminiStream isn't fully parsing it yet)
	expectedWriterContent := input
	if writer.String() != expectedWriterContent {
		t.Errorf("writer content mismatch:\nwant:\n%s\ngot:\n%s", expectedWriterContent, writer.String())
	}
}

// TestGeminiRunner_Run_ProjectDir_RunsInSandbox verifies that when project_dir
// is set, the gemini subprocess runs inside a sandbox clone — not in
// project_dir itself.
func TestGeminiRunner_Run_ProjectDir_RunsInSandbox(t *testing.T) {
	projectDir := t.TempDir()
	initGitRepo(t, projectDir)

	logDir := t.TempDir()
	cwdFile := filepath.Join(logDir, "gemini-cwd.txt")

	// Fake gemini binary that records its $PWD then exits 0.
	scriptPath := filepath.Join(t.TempDir(), "fake-gemini.sh")
	script := "#!/bin/sh\nprintf '%s' \"$PWD\" > " + cwdFile + "\n"
	if err := os.WriteFile(scriptPath, []byte(script), 0755); err != nil {
		t.Fatalf("write script: %v", err)
	}

	r := &GeminiRunner{
		BinaryPath: scriptPath,
		Logger:     slog.New(slog.NewTextHandler(io.Discard, nil)),
		LogDir:     logDir,
	}
	tk := &task.Task{
		Agent: task.AgentConfig{
			Type:         "gemini",
			Instructions: "do work",
			ProjectDir:   projectDir,
			SkipPlanning: true,
		},
	}
	e := &storage.Execution{ID: "sandbox-exec", TaskID: "task-1"}

	if err := r.Run(context.Background(), tk, e); err != nil {
		t.Fatalf("Run: %v", err)
	}

	got, err := os.ReadFile(cwdFile)
	if err != nil {
		t.Fatalf("cwd file not written: %v", err)
	}
	cwd := string(got)
	if cwd == projectDir {
		t.Errorf("ran directly in project_dir; expected sandbox clone (cwd=%q)", cwd)
	}
	// Sandbox should be removed after successful teardown (no edits → nothing to push).
	// We can't assert the exact dir, but it should not be projectDir.
}

// TestGeminiRunner_Run_BlockedError_IncludesSandboxDir verifies that when the
// agent writes a question file before exiting, the BlockedError carries the
// sandbox path so resume runs in the same dir.
func TestGeminiRunner_Run_BlockedError_IncludesSandboxDir(t *testing.T) {
	src := t.TempDir()
	initGitRepo(t, src)
	logDir := t.TempDir()

	scriptPath := filepath.Join(t.TempDir(), "fake-gemini.sh")
	if err := os.WriteFile(scriptPath, []byte(`#!/bin/sh
if [ -n "$CLAUDOMATOR_QUESTION_FILE" ]; then
  printf '{"text":"Should I continue?"}' > "$CLAUDOMATOR_QUESTION_FILE"
fi
`), 0755); err != nil {
		t.Fatalf("write script: %v", err)
	}

	r := &GeminiRunner{
		BinaryPath: scriptPath,
		Logger:     slog.New(slog.NewTextHandler(io.Discard, nil)),
		LogDir:     logDir,
	}
	tk := &task.Task{
		Agent: task.AgentConfig{
			Type:         "gemini",
			Instructions: "do something",
			ProjectDir:   src,
			SkipPlanning: true,
		},
	}
	e := &storage.Execution{ID: "blocked-gemini-exec", TaskID: "task-1"}

	err := r.Run(context.Background(), tk, e)

	var blocked *BlockedError
	if !errors.As(err, &blocked) {
		t.Fatalf("expected BlockedError, got: %v", err)
	}
	if blocked.SandboxDir == "" {
		t.Error("BlockedError.SandboxDir should be set when gemini task runs in a sandbox")
	}
	if _, statErr := os.Stat(blocked.SandboxDir); os.IsNotExist(statErr) {
		t.Error("sandbox directory should be preserved when blocked")
	} else {
		os.RemoveAll(blocked.SandboxDir)
	}
}

// TestGeminiRunner_Run_ExecError_PreservesSandbox verifies that when gemini
// exits non-zero, the sandbox path is included in the wrapped error so the
// user can inspect partial work.
func TestGeminiRunner_Run_ExecError_PreservesSandbox(t *testing.T) {
	src := t.TempDir()
	initGitRepo(t, src)
	logDir := t.TempDir()

	// "false" exits 1, no output.
	r := &GeminiRunner{
		BinaryPath: "false",
		Logger:     slog.New(slog.NewTextHandler(io.Discard, nil)),
		LogDir:     logDir,
	}
	tk := &task.Task{
		Agent: task.AgentConfig{
			Type:         "gemini",
			Instructions: "do something",
			ProjectDir:   src,
			SkipPlanning: true,
		},
	}
	e := &storage.Execution{ID: "err-gemini-exec", TaskID: "task-1"}

	err := r.Run(context.Background(), tk, e)
	if err == nil {
		t.Fatal("expected error from failing gemini exit")
	}
	if !strings.Contains(err.Error(), "sandbox preserved at ") {
		t.Errorf("expected error to include sandbox path; got: %v", err)
	}
	// Extract path and verify it exists.
	idx := strings.Index(err.Error(), "sandbox preserved at ")
	rest := err.Error()[idx+len("sandbox preserved at "):]
	rest = strings.TrimSuffix(rest, ")")
	rest = strings.TrimSpace(rest)
	if _, statErr := os.Stat(rest); os.IsNotExist(statErr) {
		t.Errorf("sandbox path from error should exist on disk: %q", rest)
	} else {
		os.RemoveAll(rest)
	}
}

// TestGeminiRunner_Run_ResumeUsesStoredSandboxDir verifies that a resume
// execution runs in the preserved SandboxDir rather than cloning fresh.
func TestGeminiRunner_Run_ResumeUsesStoredSandboxDir(t *testing.T) {
	logDir := t.TempDir()
	sandboxDir := t.TempDir()
	initGitRepo(t, sandboxDir)
	cwdFile := filepath.Join(logDir, "cwd.txt")

	scriptPath := filepath.Join(t.TempDir(), "fake-gemini.sh")
	script := "#!/bin/sh\nprintf '%s' \"$PWD\" > " + cwdFile + "\n"
	if err := os.WriteFile(scriptPath, []byte(script), 0755); err != nil {
		t.Fatalf("write script: %v", err)
	}

	r := &GeminiRunner{
		BinaryPath: scriptPath,
		Logger:     slog.New(slog.NewTextHandler(io.Discard, nil)),
		LogDir:     logDir,
	}
	tk := &task.Task{
		Agent: task.AgentConfig{
			Type:         "gemini",
			SkipPlanning: true,
		},
	}
	e := &storage.Execution{
		ID:              "resume-gemini-1",
		TaskID:          "task-resume",
		ResumeSessionID: "session-abc",
		SandboxDir:      sandboxDir,
	}

	if err := r.Run(context.Background(), tk, e); err != nil {
		t.Fatalf("Run with preserved sandbox: %v", err)
	}

	got, err := os.ReadFile(cwdFile)
	if err != nil {
		t.Fatalf("cwd file not written: %v", err)
	}
	if string(got) != sandboxDir {
		t.Errorf("resume should run in preserved sandbox; got cwd=%q want %q", got, sandboxDir)
	}
}

// TestGeminiRunner_Run_StaleSandboxDir_ClonesAfresh verifies that a resume
// pointing at a missing sandbox falls back to cloning a fresh sandbox from
// project_dir rather than failing outright.
func TestGeminiRunner_Run_StaleSandboxDir_ClonesAfresh(t *testing.T) {
	logDir := t.TempDir()
	projectDir := t.TempDir()
	initGitRepo(t, projectDir)

	cwdFile := filepath.Join(logDir, "cwd.txt")
	scriptPath := filepath.Join(t.TempDir(), "fake-gemini.sh")
	script := "#!/bin/sh\nprintf '%s' \"$PWD\" > " + cwdFile + "\n"
	if err := os.WriteFile(scriptPath, []byte(script), 0755); err != nil {
		t.Fatalf("write script: %v", err)
	}

	r := &GeminiRunner{
		BinaryPath: scriptPath,
		Logger:     slog.New(slog.NewTextHandler(io.Discard, nil)),
		LogDir:     logDir,
	}
	tk := &task.Task{
		Agent: task.AgentConfig{
			Type:         "gemini",
			ProjectDir:   projectDir,
			SkipPlanning: true,
		},
	}
	staleSandbox := filepath.Join(t.TempDir(), "gone")
	e := &storage.Execution{
		ID:              "resume-gemini-2",
		TaskID:          "task-stale",
		ResumeSessionID: "session-xyz",
		SandboxDir:      staleSandbox,
	}

	if err := r.Run(context.Background(), tk, e); err != nil {
		t.Fatalf("Run with stale sandbox: %v", err)
	}

	got, err := os.ReadFile(cwdFile)
	if err != nil {
		t.Fatalf("cwd file not written: %v", err)
	}
	cwd := string(got)
	if cwd == staleSandbox {
		t.Error("ran in stale (nonexistent) sandbox dir")
	}
	if cwd == projectDir {
		t.Error("ran directly in project_dir; expected a fresh sandbox clone")
	}
}

// TestGeminiRunner_Run_NoProjectDir_SkipsSandbox verifies that a task with no
// project_dir doesn't trigger sandbox setup (matches LocalRunner/non-coding
// task semantics).
func TestGeminiRunner_Run_NoProjectDir_SkipsSandbox(t *testing.T) {
	logDir := t.TempDir()

	r := &GeminiRunner{
		BinaryPath: "true", // exits 0, no output
		Logger:     slog.New(slog.NewTextHandler(io.Discard, nil)),
		LogDir:     logDir,
	}
	tk := &task.Task{
		Agent: task.AgentConfig{
			Type:         "gemini",
			Instructions: "summarize: 2+2",
			SkipPlanning: true,
			// No ProjectDir
		},
	}
	e := &storage.Execution{ID: "no-pd-gemini", TaskID: "task-nopd"}

	if err := r.Run(context.Background(), tk, e); err != nil {
		t.Fatalf("Run without project_dir: %v", err)
	}
	if e.SandboxDir != "" {
		t.Errorf("SandboxDir should be empty for tasks without project_dir, got %q", e.SandboxDir)
	}
}