package api

import (
	"bytes"
	"encoding/json"
	"fmt"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"testing"
)

// createFakeClaude writes a stub `claude` script that prints the given output
// and exits with the given code, returning its path for use as a binary
// override in tests.
func createFakeClaude(t *testing.T, output string, exitCode int) string {
	t.Helper()
	dir := t.TempDir()
	outputFile := filepath.Join(dir, "output.json")
	if err := os.WriteFile(outputFile, []byte(output), 0600); err != nil {
		t.Fatal(err)
	}
	script := filepath.Join(dir, "claude")
	content := fmt.Sprintf("#!/bin/sh\ncat %q\nexit %d\n", outputFile, exitCode)
	if err := os.WriteFile(script, []byte(content), 0755); err != nil {
		t.Fatal(err)
	}
	return script
}

func TestValidateTask_Success(t *testing.T) {
	srv, _ := testServer(t)

	validResult := validateResult{
		Clarity:     "clear",
		Ready:       true,
		Summary:     "Instructions are clear and actionable.",
		Questions:   []validateQuestion{},
		Suggestions: []string{},
	}
	resultJSON, _ := json.Marshal(validResult)
	wrapper := map[string]string{"result": string(resultJSON)}
	wrapperJSON, _ := json.Marshal(wrapper)
	srv.validateCmdPath = createFakeClaude(t, string(wrapperJSON), 0)

	body := `{"name":"Test Task","agent":{"instructions":"Run go test ./... and report results."}}`
	req := httptest.NewRequest("POST", "/api/tasks/validate", bytes.NewBufferString(body))
	req.Header.Set("Content-Type", "application/json")
	w := httptest.NewRecorder()

	srv.Handler().ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("status: want 200, got %d; body: %s", w.Code, w.Body.String())
	}

	var result validateResult
	if err := json.NewDecoder(w.Body).Decode(&result); err != nil {
		t.Fatalf("failed to decode response: %v", err)
	}
	if result.Clarity == "" {
		t.Error("expected non-empty clarity field in response")
	}
}

func TestValidateTask_MissingInstructions(t *testing.T) {
	srv, _ := testServer(t)

	body := `{"name":"Test Task","agent":{"instructions":""}}`
	req := httptest.NewRequest("POST", "/api/tasks/validate", bytes.NewBufferString(body))
	req.Header.Set("Content-Type", "application/json")
	w := httptest.NewRecorder()

	srv.Handler().ServeHTTP(w, req)

	if w.Code != http.StatusBadRequest {
		t.Fatalf("status: want 400, got %d; body: %s", w.Code, w.Body.String())
	}
}

func TestValidateTask_MissingName(t *testing.T) {
	srv, _ := testServer(t)

	body := `{"name":"","agent":{"instructions":"Do something useful."}}`
	req := httptest.NewRequest("POST", "/api/tasks/validate", bytes.NewBufferString(body))
	req.Header.Set("Content-Type", "application/json")
	w := httptest.NewRecorder()

	srv.Handler().ServeHTTP(w, req)

	if w.Code != http.StatusBadRequest {
		t.Fatalf("status: want 400, got %d; body: %s", w.Code, w.Body.String())
	}
}

func TestValidateTask_BadJSONFromClaude(t *testing.T) {
	srv, _ := testServer(t)
	srv.validateCmdPath = createFakeClaude(t, "not valid json at all", 0)

	body := `{"name":"Test Task","agent":{"instructions":"Do something useful."}}`
	req := httptest.NewRequest("POST", "/api/tasks/validate", bytes.NewBufferString(body))
	req.Header.Set("Content-Type", "application/json")
	w := httptest.NewRecorder()

	srv.Handler().ServeHTTP(w, req)

	if w.Code != http.StatusBadGateway {
		t.Fatalf("status: want 502, got %d; body: %s", w.Code, w.Body.String())
	}
}