//! Comprehensive encryption error tests for pdftract CLI
//!
//! This module tests encryption-related error cases and verifies that:
//! 1. Unsupported encryption handlers emit ENCRYPTION_UNSUPPORTED and exit code 3
//! 2. Supported encrypted PDFs can be decrypted with correct passwords
//! 3. Wrong/missing passwords emit appropriate errors
//! 4. Various encryption algorithms (RC4, AES-128, AES-256) are handled correctly
//!
//! Test fixtures:
//! - tests/fixtures/encrypted/EC-04-rc4-encrypted.pdf (RC4 encryption)
//! - tests/fixtures/encrypted/EC-05-aes128-encrypted.pdf (AES-128 encryption)
//! - tests/fixtures/encrypted/EC-06-aes256-encrypted.pdf (AES-256 encryption)
//! - tests/fixtures/encrypted/EC-empty-password.pdf (empty password)
//! - tests/fixtures/encrypted/livecycle.pdf (unsupported Adobe.APS handler)
//!
//! References:
//! - Plan line 258, Failure Mode Taxonomy: ENCRYPTION_UNSUPPORTED
//! - Plan line 732: Encryption-unsupported diagnostic and CLI exit code 3
//! - Plan line 1132: RC4 and AES-128/256 decryption implementation
//! - Plan line 1149: Encrypted file with unknown handler error handling

use std::fs;
use std::path::{Path, PathBuf};
use std::process::Command;

/// Get the workspace root directory
fn workspace_root() -> PathBuf {
    let manifest_dir = std::env::var("CARGO_MANIFEST_DIR").unwrap();
    let path = PathBuf::from(manifest_dir);
    // We're in crates/pdftract-cli, so go up two levels to reach workspace root
    path.parent().unwrap().parent().unwrap().to_path_buf()
}

/// Path to encrypted fixtures directory
fn encrypted_fixture_dir() -> PathBuf {
    workspace_root().join("tests/fixtures/encrypted")
}

/// Path to a specific encrypted fixture
fn encrypted_fixture(name: &str) -> PathBuf {
    encrypted_fixture_dir().join(name)
}

/// Path to pdftract CLI binary
fn pdftract_bin() -> PathBuf {
    let mut path = workspace_root();
    path.push("target/debug/pdftract");
    path
}

/// Exit code for encryption errors (per spec)
const ENCRYPTION_EXIT_CODE: i32 = 3;

/// Expected encrypted fixture files
const ENCRYPTED_FIXTURES: &[&str] = &[
    "EC-04-rc4-encrypted.pdf",
    "EC-05-aes128-encrypted.pdf",
    "EC-06-aes256-encrypted.pdf",
    "EC-empty-password.pdf",
    "livecycle.pdf",
];

// ============================================================================
// Module: Unsupported Encryption Handlers
// ============================================================================

mod unsupported_handlers {
    use super::*;

    /// Test that livecycle.pdf (unsupported Adobe.APS encryption handler)
    /// triggers ENCRYPTION_UNSUPPORTED and exits with code 3
    #[test]
    #[ignore = "Requires ENCRYPTION_UNSUPPORTED exit code implementation"]
    fn test_livecycle_pdf_emits_encryption_unsupported() {
        let fixture = encrypted_fixture("livecycle.pdf");
        assert!(
            fixture.exists(),
            "Fixture not found: {}",
            fixture.display()
        );

        let output = Command::new(pdftract_bin())
            .args(["extract", fixture.to_str().unwrap()])
            .output()
            .expect("Failed to run pdftract extract on livecycle.pdf");

        // Exit code 3 for encryption errors (per spec)
        assert_eq!(
            output.status.code(),
            Some(ENCRYPTION_EXIT_CODE),
            "Expected exit code {} for ENCRYPTION_UNSUPPORTED, got {:?}",
            ENCRYPTION_EXIT_CODE,
            output.status.code()
        );

        // stderr should contain the error message
        let stderr = String::from_utf8_lossy(&output.stderr);

        assert!(
            stderr.contains("Unsupported encryption") || stderr.contains("ENCRYPTION_UNSUPPORTED"),
            "Expected stderr to contain 'Unsupported encryption' or 'ENCRYPTION_UNSUPPORTED', got: {}",
            stderr
        );

        // stdout should be empty or minimal (no extraction output)
        let stdout = String::from_utf8_lossy(&output.stdout);
        assert!(
            stdout.is_empty() || !stdout.contains("\"pages\""),
            "Expected no extraction output in stdout, got: {}",
            stdout
        );
    }

    /// Test that even with a password, livecycle.pdf still fails because
    /// the Adobe.APS handler is unsupported (not a password issue)
    #[test]
    #[ignore = "Requires --password-stdin implementation or INSECURE_CLI_PASSWORD handling"]
    fn test_livecycle_pdf_with_password_also_fails() {
        let fixture = encrypted_fixture("livecycle.pdf");
        assert!(
            fixture.exists(),
            "Fixture not found: {}",
            fixture.display()
        );

        let output = Command::new(pdftract_bin())
            .args(["extract", fixture.to_str().unwrap()])
            .stdin(std::process::Stdio::piped())
            .stdout(std::process::Stdio::piped())
            .stderr(std::process::Stdio::piped())
            .output()
            .expect("Failed to run pdftract extract with password stdin");

        // Should still exit with code 3 (unsupported algorithm, not wrong password)
        assert_eq!(
            output.status.code(),
            Some(ENCRYPTION_EXIT_CODE),
            "Expected exit code {} for unsupported algorithm even with password, got {:?}",
            ENCRYPTION_EXIT_CODE,
            output.status.code()
        );
    }
}

// ============================================================================
// Module: Supported Encryption with Correct Passwords
// ============================================================================

mod supported_encryption {
    use super::*;

    /// Test that RC4-encrypted PDF can be decrypted with correct password
    #[test]
    #[ignore = "Requires password-based decryption implementation"]
    fn test_rc4_encrypted_with_correct_password() {
        let fixture = encrypted_fixture("EC-04-rc4-encrypted.pdf");
        assert!(
            fixture.exists(),
            "Fixture not found: {}",
            fixture.display()
        );

        // TODO: Implement once password CLI flag is available
        // Expected: successful extraction with correct password
    }

    /// Test that AES-128-encrypted PDF can be decrypted with correct password
    #[test]
    #[ignore = "Requires password-based decryption implementation"]
    fn test_aes128_encrypted_with_correct_password() {
        let fixture = encrypted_fixture("EC-05-aes128-encrypted.pdf");
        assert!(
            fixture.exists(),
            "Fixture not found: {}",
            fixture.display()
        );

        // TODO: Implement once password CLI flag is available
        // Expected: successful extraction with correct password
    }

    /// Test that AES-256-encrypted PDF can be decrypted with correct password
    #[test]
    #[ignore = "Requires password-based decryption implementation"]
    fn test_aes256_encrypted_with_correct_password() {
        let fixture = encrypted_fixture("EC-06-aes256-encrypted.pdf");
        assert!(
            fixture.exists(),
            "Fixture not found: {}",
            fixture.display()
        );

        // TODO: Implement once password CLI flag is available
        // Expected: successful extraction with correct password
    }

    /// Test that empty-password PDF can be opened (no password required)
    #[test]
    #[ignore = "Requires empty password handling implementation"]
    fn test_empty_password_pdf_opens() {
        let fixture = encrypted_fixture("EC-empty-password.pdf");
        assert!(
            fixture.exists(),
            "Fixture not found: {}",
            fixture.display()
        );

        // TODO: Implement once empty password auto-detection is available
        // Expected: successful extraction without password
    }
}

// ============================================================================
// Module: Wrong/Missing Password Handling
// ============================================================================

mod password_errors {
    use super::*;

    /// Test that wrong password emits appropriate error
    #[test]
    #[ignore = "Requires password-based decryption implementation"]
    fn test_wrong_password_emits_error() {
        let fixture = encrypted_fixture("EC-04-rc4-encrypted.pdf");
        assert!(
            fixture.exists(),
            "Fixture not found: {}",
            fixture.display()
        );

        // TODO: Implement once password CLI flag is available
        // Expected: exit code 3 with appropriate error message
    }

    /// Test that missing required password emits appropriate error
    #[test]
    #[ignore = "Requires password-based decryption implementation"]
    fn test_missing_required_password_emits_error() {
        let fixture = encrypted_fixture("EC-05-aes128-encrypted.pdf");
        assert!(
            fixture.exists(),
            "Fixture not found: {}",
            fixture.display()
        );

        // TODO: Implement once password requirement detection is available
        // Expected: exit code 3 with appropriate error message
    }
}

// ============================================================================
// Module: Fixture Structure Validation
// ============================================================================

mod fixture_validation {
    use super::*;

    /// Verify all encrypted fixture files exist
    #[test]
    fn test_encrypted_fixtures_exist() {
        let fixture_dir = encrypted_fixture_dir();
        assert!(
            fixture_dir.exists(),
            "Encrypted fixtures directory not found: {}",
            fixture_dir.display()
        );

        for fixture_name in ENCRYPTED_FIXTURES {
            let path = encrypted_fixture(fixture_name);
            assert!(
                path.exists(),
                "Encrypted fixture not found: {}",
                path.display()
            );
        }
    }

    /// Verify fixture files are valid PDFs (basic structure check)
    #[test]
    fn test_encrypted_fixtures_are_valid_pdfs() {
        for fixture_name in ENCRYPTED_FIXTURES {
            let path = encrypted_fixture(fixture_name);

            let content = fs::read(&path).expect(&format!(
                "Failed to read fixture: {}",
                path.display()
            ));

            // Check for PDF magic number (%PDF-)
            assert!(
                content.starts_with(b"%PDF-"),
                "Fixture {} is not a valid PDF (missing %PDF- header)",
                fixture_name
            );

            // Check for EOF marker
            let content_str = String::from_utf8_lossy(&content);
            assert!(
                content_str.contains("%%EOF"),
                "Fixture {} is not a valid PDF (missing %%EOF marker)",
                fixture_name
            );
        }
    }

    /// Verify expected output files exist for supported encryption tests
    #[test]
    fn test_expected_outputs_exist() {
        let fixture_dir = encrypted_fixture_dir();

        // Check for expected output files for supported encryption types
        let expected_outputs = &[
            "EC-04-rc4-encrypted.expected.json",
            "EC-05-aes128-encrypted.expected.json",
        ];

        for expected_name in expected_outputs {
            let path = fixture_dir.join(expected_name);
            assert!(
                path.exists(),
                "Expected output file not found: {}",
                path.display()
            );
        }
    }
}

// ============================================================================
// Module: Integration Tests (Placeholder for Future Implementation)
// ============================================================================

#[cfg(test)]
mod integration_tests {
    use super::*;

    /// Integration test: Complete extraction workflow for supported encrypted PDFs
    #[test]
    #[ignore = "Requires complete password-based decryption implementation"]
    fn test_encrypted_pdf_extraction_workflow() {
        // This will test the complete workflow:
        // 1. Detect encryption
        // 2. Prompt for password / accept --password flag
        // 3. Decrypt PDF
        // 4. Extract content
        // 5. Verify output matches expected.json
    }

    /// Integration test: Error recovery workflow for unsupported encryption
    #[test]
    #[ignore = "Requires error recovery implementation"]
    fn test_unsupported_encryption_error_recovery() {
        // This will test error recovery:
        // 1. Detect unsupported encryption
        // 2. Emit ENCRYPTION_UNSUPPORTED diagnostic
        // 3. Exit with code 3
        // 4. Provide helpful error message
    }
}