package review

import (
	"os"
	"path/filepath"
	"testing"
)

func TestLoadBuiltinPersona(t *testing.T) {
	tests := []struct {
		name        string
		personaName string
		wantErr     bool
		wantDisplay string
	}{
		{
			name:        "security persona",
			personaName: "security",
			wantErr:     false,
			wantDisplay: "Security Specialist",
		},
		{
			name:        "architect persona",
			personaName: "architect",
			wantErr:     false,
			wantDisplay: "Architecture Reviewer",
		},
		{
			name:        "docs persona",
			personaName: "docs",
			wantErr:     false,
			wantDisplay: "Documentation Reviewer",
		},
		{
			name:        "unknown persona",
			personaName: "nonexistent",
			wantErr:     true,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			p, err := LoadBuiltinPersona(tt.personaName)
			if tt.wantErr {
				if err == nil {
					t.Error("expected error, got nil")
				}
				return
			}
			if err != nil {
				t.Fatalf("unexpected error: %v", err)
			}
			if p.Name != tt.personaName {
				t.Errorf("Name = %q, want %q", p.Name, tt.personaName)
			}
			if p.DisplayName != tt.wantDisplay {
				t.Errorf("DisplayName = %q, want %q", p.DisplayName, tt.wantDisplay)
			}
			if p.Identity == "" {
				t.Error("Identity should not be empty")
			}
			if len(p.Focus) == 0 {
				t.Error("Focus should not be empty")
			}
		})
	}
}

func TestListBuiltinPersonas(t *testing.T) {
	names := ListBuiltinPersonas()
	if len(names) == 0 {
		t.Fatal("expected at least one built-in persona")
	}

	// Check for expected personas
	expected := map[string]bool{"security": false, "architect": false, "docs": false}
	for _, name := range names {
		if _, ok := expected[name]; ok {
			expected[name] = true
		}
	}
	for name, found := range expected {
		if !found {
			t.Errorf("expected built-in persona %q not found", name)
		}
	}
}

func TestLoadPersonaFromFile(t *testing.T) {
	// Create a temp persona file
	dir := t.TempDir()
	path := filepath.Join(dir, "test.json")

	content := `{
		"name": "test",
		"display_name": "Test Persona",
		"identity": "You are a test persona.",
		"focus": ["testing"],
		"ignore": ["nothing"],
		"severity": {
			"major": "Big problems",
			"minor": "Small problems",
			"nit": "Tiny problems"
		}
	}`

	if err := os.WriteFile(path, []byte(content), 0644); err != nil {
		t.Fatalf("failed to write test file: %v", err)
	}

	p, err := LoadPersona(path)
	if err != nil {
		t.Fatalf("LoadPersona failed: %v", err)
	}

	if p.Name != "test" {
		t.Errorf("Name = %q, want %q", p.Name, "test")
	}
	if p.DisplayName != "Test Persona" {
		t.Errorf("DisplayName = %q, want %q", p.DisplayName, "Test Persona")
	}
}

func TestLoadPersonaValidation(t *testing.T) {
	tests := []struct {
		name    string
		json    string
		wantErr string
	}{
		{
			name:    "missing name",
			json:    `{"identity": "test"}`,
			wantErr: "name is required",
		},
		{
			name:    "missing identity",
			json:    `{"name": "test"}`,
			wantErr: "identity is required",
		},
		{
			name: "display_name defaults to name",
			json: `{"name": "test", "identity": "test identity"}`,
			// No error expected - should succeed
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			dir := t.TempDir()
			path := filepath.Join(dir, "test.json")
			if err := os.WriteFile(path, []byte(tt.json), 0644); err != nil {
				t.Fatalf("failed to write test file: %v", err)
			}

			p, err := LoadPersona(path)
			if tt.wantErr != "" {
				if err == nil {
					t.Errorf("expected error containing %q, got nil", tt.wantErr)
					return
				}
				if !contains(err.Error(), tt.wantErr) {
					t.Errorf("error = %q, want containing %q", err.Error(), tt.wantErr)
				}
				return
			}
			if err != nil {
				t.Fatalf("unexpected error: %v", err)
			}
			// Check display_name defaulting
			if p.DisplayName == "" {
				t.Error("DisplayName should default to Name")
			}
			if p.DisplayName != p.Name {
				t.Errorf("DisplayName should default to Name, got %q", p.DisplayName)
			}
		})
	}
}

func TestLoadPersonaFileNotFound(t *testing.T) {
	_, err := LoadPersona("/nonexistent/path/persona.json")
	if err == nil {
		t.Error("expected error for nonexistent file")
	}
}

func TestLoadPersonaInvalidJSON(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "invalid.json")
	if err := os.WriteFile(path, []byte("not json"), 0644); err != nil {
		t.Fatalf("failed to write test file: %v", err)
	}

	_, err := LoadPersona(path)
	if err == nil {
		t.Error("expected error for invalid JSON")
	}
}

func contains(s, substr string) bool {
	return len(s) >= len(substr) && (s == substr || len(s) > 0 && containsHelper(s, substr))
}

func containsHelper(s, substr string) bool {
	for i := 0; i <= len(s)-len(substr); i++ {
		if s[i:i+len(substr)] == substr {
			return true
		}
	}
	return false
}