//! CLI invocation fixture discovery and enumeration
//!
//! This test module provides comprehensive fixture discovery for CLI testing:
//! - Discovers all PDF fixtures from the main test fixtures directory
//! - Provides test-accessible fixture enumeration
//! - Supports category-based filtering (encrypted, forms, ocr, malformed, etc.)
//! - Enables bulk CLI invocation testing
//!
//! The fixtures are organized in /tests/fixtures/ by category:
//! - encrypted/: Password-protected and encrypted PDFs
//! - forms/: PDFs with AcroForm and XFA forms
//! - ocr/: Scanned documents requiring OCR processing
//! - malformed/: Corrupted or malformed PDFs for error handling
//! - scanned/: Scanned documents and receipts
//! - cjk/: Chinese/Japanese/Korean language documents
//! - fonts/: PDFs with various font encodings and subsets
//! - And more...

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

/// Get the path to the main workspace fixtures directory
///
/// The main fixtures directory is at /tests/fixtures/ in the workspace root,
/// not to be confused with the crate-specific fixtures/ directory.
fn main_fixtures_dir() -> PathBuf {
    // CARGO_MANIFEST_DIR is /home/coding/pdftract/crates/pdftract-cli
    // We need to go up to workspace root, then into tests/fixtures
    let mut path = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
    path.push("../../tests/fixtures");
    path
}

/// Get the path to the pdftract binary (cargo build output)
fn pdftract_bin() -> PathBuf {
    // The binary should be built at target/debug/pdftract or target/release/pdftract
    // CARGO_MANIFEST_DIR is the crate directory; workspace target is two levels up
    let mut path = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
    path.push("../../target/debug/pdftract");

    // Fall back to release if debug doesn't exist
    if !path.exists() {
        let mut release_path = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
        release_path.push("../../target/release/pdftract");
        return release_path;
    }

    path
}

/// Discover all PDF files in the given directory recursively using walkdir.
///
/// # Arguments
/// * `fixtures_path` - Path to the fixtures directory to search
///
/// # Returns
/// A `Vec<PathBuf>` containing paths to all discovered PDF files, sorted alphabetically
fn discover_pdf_fixtures<P: AsRef<Path>>(fixtures_path: P) -> Vec<PathBuf> {
    let mut pdf_files = Vec::new();

    let walker = WalkDir::new(fixtures_path)
        .follow_links(false)
        .into_iter()
        .filter_map(|e| e.ok())
        .filter(|e| {
            e.file_type().is_file()
                && e.path()
                    .extension()
                    .map(|ext| ext == "pdf")
                    .unwrap_or(false)
        })
        .map(|e| e.path().to_path_buf());

    pdf_files.extend(walker);
    pdf_files.sort();

    pdf_files
}

/// Discover PDF files in a specific category subdirectory
///
/// # Arguments
/// * `category` - Category name (e.g., "encrypted", "forms", "ocr")
///
/// # Returns
/// A `Vec<PathBuf>` containing paths to PDF files in that category
fn discover_fixtures_by_category(category: &str) -> Vec<PathBuf> {
    let fixtures_dir = main_fixtures_dir();
    let category_path = fixtures_dir.join(category);

    if !category_path.exists() {
        return Vec::new();
    }

    discover_pdf_fixtures(&category_path)
}

/// Get all fixture categories present in the main fixtures directory
///
/// # Returns
/// A `Vec<String>` of category names (subdirectory names containing PDF files)
fn get_fixture_categories() -> Vec<String> {
    let fixtures_dir = main_fixtures_dir();
    let mut categories = Vec::new();

    if let Ok(entries) = std::fs::read_dir(&fixtures_dir) {
        for entry in entries.flatten() {
            let path = entry.path();
            if path.is_dir() {
                // Check if this directory contains PDF files
                let has_pdfs = discover_pdf_fixtures(&path).iter().any(|p| p.exists());
                if has_pdfs {
                    if let Some(name) = path.file_name() {
                        categories.push(name.to_string_lossy().to_string());
                    }
                }
            }
        }
    }

    categories.sort();
    categories
}

/// Test that the main fixtures directory exists and is accessible
#[test]
fn test_main_fixtures_dir_exists() {
    let fixtures_dir = main_fixtures_dir();
    assert!(fixtures_dir.exists(), "Main fixtures directory does not exist: {:?}", fixtures_dir);
    assert!(fixtures_dir.is_dir(), "Main fixtures path is not a directory: {:?}", fixtures_dir);

    println!("Main fixtures directory: {:?}", fixtures_dir);
}

/// Test fixture discovery mechanism and print discovered fixtures
///
/// This test verifies that the walkdir-based PDF discovery function works correctly
/// and prints the names of all discovered fixtures to stdout.
#[test]
fn test_discover_all_pdf_fixtures() {
    let fixtures_dir = main_fixtures_dir();
    let pdf_files = discover_pdf_fixtures(&fixtures_dir);

    println!("\n=== Discovered PDF Fixtures ===");
    println!("Fixtures directory: {}", fixtures_dir.display());

    if pdf_files.is_empty() {
        println!("No PDF files found in {}", fixtures_dir.display());
    } else {
        println!("Total PDF files discovered: {}", pdf_files.len());

        // Group by category for better readability
        let mut by_category: std::collections::HashMap<String, Vec<&PathBuf>> = std::collections::HashMap::new();

        for pdf_path in &pdf_files {
            if let Some(category) = pdf_path.parent().and_then(|p| p.file_name()) {
                let category_name = category.to_string_lossy().to_string();
                by_category.entry(category_name).or_default().push(pdf_path);
            }
        }

        let mut sorted_categories: Vec<_> = by_category.iter().collect();
        sorted_categories.sort_by(|a, b| a.0.cmp(b.0));

        for (category, files) in sorted_categories {
            println!("\n[{}] {} file(s):", category, files.len());
            for pdf_path in files {
                let relative_path = pdf_path.strip_prefix(&fixtures_dir).unwrap_or(pdf_path);
                println!("  - {}", relative_path.display());
            }
        }
    }
    println!("==============================\n");

    // Test that the function runs without errors
    // (We don't assert a count since fixtures may be added/removed)
    let _ = pdf_files;
}

/// Test category-based fixture discovery
#[test]
fn test_discover_fixtures_by_category() {
    println!("\n=== Category-based Fixture Discovery ===\n");

    // Get all available categories
    let categories = get_fixture_categories();
    println!("Available fixture categories: {}", categories.len());

    for category in &categories {
        let fixtures = discover_fixtures_by_category(category);
        println!("[{}] {} PDF file(s)", category, fixtures.len());
    }

    println!("\n=========================================\n");

    // Verify we have some expected categories
    assert!(categories.len() > 0, "No fixture categories found");
}

/// Test that we can enumerate fixtures for CLI processing
///
/// This test ensures that fixtures can be enumerated in a format suitable
/// for bulk CLI invocation testing.
#[test]
fn test_fixture_enumeration_for_cli() {
    let fixtures_dir = main_fixtures_dir();
    let pdf_files = discover_pdf_fixtures(&fixtures_dir);
    let bin = pdftract_bin();

    // Ensure binary exists
    assert!(bin.exists(), "pdftract binary not found at {:?}", bin);

    println!("\n=== Fixture Enumeration for CLI Testing ===");
    println!("Binary path: {:?}", bin);
    println!("Fixtures directory: {}", fixtures_dir.display());
    println!("Total fixtures discovered: {}\n", pdf_files.len());

    // If no fixtures yet, test passes (scaffold for future fixtures)
    if pdf_files.is_empty() {
        println!("No PDF fixtures found - test scaffold ready");
        return;
    }

    // Print a sample of fixtures for verification
    let sample_size = 5.min(pdf_files.len());
    println!("Sample fixtures (first {} of {}):", sample_size, pdf_files.len());
    for (i, pdf_path) in pdf_files.iter().take(sample_size).enumerate() {
        let relative_path = pdf_path.strip_prefix(&fixtures_dir).unwrap_or(pdf_path);
        println!("  {}. {}", i + 1, relative_path.display());
    }

    if pdf_files.len() > sample_size {
        println!("  ... and {} more", pdf_files.len() - sample_size);
    }

    println!("\nAll fixtures are accessible for CLI processing");
    println!("==========================================\n");
}

/// Basic test that pdftract extract --json runs on discovered fixtures
///
/// This test runs `pdftract extract --json` on a small sample of discovered fixtures
/// to verify that the CLI invocation works correctly. It processes only the first
/// 5 fixtures to keep test runtime reasonable.
#[test]
fn test_cli_invocation_on_fixture_sample() {
    let fixtures_dir = main_fixtures_dir();
    let pdf_files = discover_pdf_fixtures(&fixtures_dir);
    let bin = pdftract_bin();

    // Ensure binary exists
    assert!(bin.exists(), "pdftract binary not found at {:?}", bin);

    // If no fixtures yet, test passes (scaffold for future fixtures)
    if pdf_files.is_empty() {
        println!("No PDF fixtures found - test scaffold ready");
        return;
    }

    // Process only a small sample to keep test runtime reasonable
    let sample_size = 5.min(pdf_files.len());
    let sample = &pdf_files[..sample_size];

    println!("\n=== CLI Invocation Test (Sample of {} fixtures) ===\n", sample_size);

    let mut success_count = 0;
    let mut failure_count = 0;

    for pdf_path in sample {
        let relative_path = pdf_path.strip_prefix(&fixtures_dir).unwrap_or(pdf_path);
        println!("Processing: {}", relative_path.display());

        // Run pdftract extract --json - on the fixture (JSON to stdout)
        let output = Command::new(&bin)
            .arg("extract")
            .arg("--json")
            .arg("-")
            .arg(pdf_path)
            .output();

        match output {
            Ok(result) => {
                if result.status.success() {
                    println!("  ✓ Success");
                    success_count += 1;
                } else {
                    println!("  ⚠ Failed with status: {}", result.status);
                    let stderr = String::from_utf8_lossy(&result.stderr);
                    if !stderr.is_empty() {
                        println!("    stderr: {}", stderr.lines().take(3).collect::<Vec<_>>().join("\n    "));
                    }
                    failure_count += 1;
                }
            }
            Err(e) => {
                println!("  ✗ Failed to run pdftract: {}", e);
                failure_count += 1;
            }
        }
    }

    println!("\nResults: {} succeeded, {} failed (out of {} sample fixtures)",
             success_count, failure_count, sample_size);
    println!("==========================================\n");

    // We don't assert all succeed since some fixtures may be malformed/encrypted
    // Just verify the mechanism works
    assert!(success_count + failure_count == sample_size,
            "Test did not complete all fixture invocations");
}