#!/usr/bin/env python3
"""Test script for line_counter.py utility.

Cells:
  1. CSV count mode on test_data.csv -> 5 fields.
  2. Line count mode on test_log.txt -> 10 lines.
  3. Blank lines count as lines: test_blank.txt is `a\n\n\nb\n` -> 4 lines.
     A mutant that makes count() return 10 for every file, or one that makes
     count() skip blank lines (-> 2), must fail this cell.
  4. Missing file -> exit code 2.
"""
import subprocess
import sys
import os

BASE_DIR = os.path.dirname(os.path.abspath(__file__))

def run_test(cmd, expected, description):
    """Run a test command and verify output."""
    result = subprocess.run(cmd, capture_output=True, text=True)
    actual = result.stdout.strip()

    if actual == str(expected) and result.returncode == 0:
        print(f"PASS: {description}")
        return True
    else:
        print(f"FAIL: {description}")
        print(f"  Expected: {expected}, Got: {actual}")
        return False

# Test CSV mode with known data
test_csv_pass = run_test(
    ['python3', f'{BASE_DIR}/line_counter.py', f'{BASE_DIR}/test_data.csv', 'csv'],
    5,
    "CSV count mode (5 items)"
)

# Test count mode with known lines
test_count_pass = run_test(
    ['python3', f'{BASE_DIR}/line_counter.py', f'{BASE_DIR}/test_log.txt', 'count'],
    10,
    "Line count mode (10 lines)"
)

# Test blank lines are lines (kills count->return 10 and count->non-blank-only)
test_blank_pass = run_test(
    ['python3', f'{BASE_DIR}/line_counter.py', f'{BASE_DIR}/test_blank.txt', 'count'],
    4,
    "Blank lines count as lines (4 on a\\n\\n\\nb\\n)"
)

# Test error handling for non-existent file
result = subprocess.run(
    ['python3', f'{BASE_DIR}/line_counter.py', f'{BASE_DIR}/nonexistent.txt', 'count'],
    capture_output=True, text=True)
if result.returncode == 2:
    print("PASS: Error handling (exit code 2 for missing file)")
    error_pass = True
else:
    print(f"FAIL: Error handling (expected exit code 2, got {result.returncode})")
    error_pass = False

all_pass = test_csv_pass and test_count_pass and test_blank_pass and error_pass
print(f"\nAll tests: {'PASSED' if all_pass else 'FAILED'}")
sys.exit(0 if all_pass else 1)