package oauth

import (
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestGenerateRandomBytes(t *testing.T) {
	t.Run("generates requested length", func(t *testing.T) {
		bytes, err := GenerateRandomBytes(32)
		require.NoError(t, err)
		assert.Equal(t, 32, len(bytes))
	})

	t.Run("generates different bytes each time", func(t *testing.T) {
		bytes1, _ := GenerateRandomBytes(16)
		bytes2, _ := GenerateRandomBytes(16)
		assert.NotEqual(t, bytes1, bytes2)
	})
}

func TestGenerateState(t *testing.T) {
	t.Run("generates non-empty state", func(t *testing.T) {
		state, err := GenerateState()
		require.NoError(t, err)
		assert.NotEmpty(t, state)
	})

	t.Run("generates unique states", func(t *testing.T) {
		state1, _ := GenerateState()
		state2, _ := GenerateState()
		assert.NotEqual(t, state1, state2)
	})

	t.Run("generates URL-safe base64", func(t *testing.T) {
		state, _ := GenerateState()
		// Should not contain padding
		assert.NotContains(t, state, "=")
	})
}

func TestGenerateSessionID(t *testing.T) {
	t.Run("generates hex string", func(t *testing.T) {
		sessionID, err := GenerateSessionID()
		require.NoError(t, err)
		assert.NotEmpty(t, sessionID)
		// Should be 32 hex chars (16 bytes * 2)
		assert.Equal(t, 32, len(sessionID))
	})

	t.Run("generates unique IDs", func(t *testing.T) {
		id1, _ := GenerateSessionID()
		id2, _ := GenerateSessionID()
		assert.NotEqual(t, id1, id2)
	})
}

func TestGenerateCodeVerifier(t *testing.T) {
	t.Run("generates verifier", func(t *testing.T) {
		verifier, err := GenerateCodeVerifier()
		require.NoError(t, err)
		assert.NotEmpty(t, verifier)
	})

	t.Run("generates unique verifiers", func(t *testing.T) {
		v1, _ := GenerateCodeVerifier()
		v2, _ := GenerateCodeVerifier()
		assert.NotEqual(t, v1, v2)
	})
}

func TestGenerateCodeChallenge(t *testing.T) {
	tests := []struct {
		name     string
		verifier string
	}{
		{"simple verifier", "test_verifier_123"},
		{"empty string", ""},
		{"long verifier", "a_very_long_verifier_string_for_testing_purposes_only"},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			challenge := GenerateCodeChallenge(tt.verifier)
			assert.NotEmpty(t, challenge)
			assert.NotContains(t, challenge, "=") // No padding
		})
	}

	t.Run("deterministic for same input", func(t *testing.T) {
		verifier := "test_verifier"
		c1 := GenerateCodeChallenge(verifier)
		c2 := GenerateCodeChallenge(verifier)
		assert.Equal(t, c1, c2)
	})
}

func TestBase64URLEncode(t *testing.T) {
	tests := []struct {
		input    []byte
		expected string
	}{
		{[]byte("hello"), "aGVsbG8"},
		{[]byte("test+123"), "dGVzdCsxMjM"},
		{[]byte(""), ""},
	}

	for _, tt := range tests {
		t.Run(string(tt.input), func(t *testing.T) {
			result := base64URLEncode(tt.input)
			assert.Equal(t, tt.expected, result)
			assert.NotContains(t, result, "=")
		})
	}
}

func TestBuildAuthorizationURL(t *testing.T) {
	url := BuildAuthorizationURL("test_state", "test_challenge", ScopeOAuth)

	assert.Contains(t, url, AuthorizeURL)
	assert.Contains(t, url, "client_id="+ClientID)
	assert.Contains(t, url, "state=test_state")
	assert.Contains(t, url, "code_challenge=test_challenge")
	assert.Contains(t, url, "code_challenge_method=S256")
	assert.Contains(t, url, "response_type=code")
}

func TestConstants(t *testing.T) {
	assert.NotEmpty(t, ClientID)
	assert.NotEmpty(t, AuthorizeURL)
	assert.NotEmpty(t, TokenURL)
	assert.NotEmpty(t, RedirectURI)
	assert.NotEmpty(t, ScopeOAuth)
	assert.NotEmpty(t, ScopeAPI)
	assert.NotEmpty(t, ScopeInference)
}

func TestTokenResponse(t *testing.T) {
	resp := TokenResponse{
		AccessToken:  "token123",
		TokenType:    "Bearer",
		ExpiresIn:    3600,
		RefreshToken: "refresh456",
		Scope:        "user:profile",
	}

	assert.Equal(t, "token123", resp.AccessToken)
	assert.Equal(t, "Bearer", resp.TokenType)
	assert.Equal(t, int64(3600), resp.ExpiresIn)
}

func TestOrgInfo(t *testing.T) {
	org := OrgInfo{UUID: "org-123"}
	assert.Equal(t, "org-123", org.UUID)
}

func TestAccountInfo(t *testing.T) {
	account := AccountInfo{
		UUID:         "acc-456",
		EmailAddress: "test@example.com",
	}
	assert.Equal(t, "acc-456", account.UUID)
	assert.Equal(t, "test@example.com", account.EmailAddress)
}