// Test runner for cleanc backend regression tests
// Run with: ./vnew run vlib/v2/gen/cleanc/tests/run_tests.v
// Or: cd vlib/v2/gen/cleanc/tests && v run run_tests.v

module main

import os
import time

fn main() {
    t0 := time.now()

    vroot := os.dir(@VEXE)
    v2_source := os.join_path(vroot, 'cmd', 'v2', 'v2.v')
    v2_binary := os.join_path(vroot, 'cmd', 'v2', 'v2')
    tests_dir := os.join_path(vroot, 'vlib', 'v2', 'gen', 'cleanc', 'tests')

    // Build v2 compiler (with v1).
    println('[*] Building v2...')
    build_res := os.execute('${@VEXE} -gc none -cc cc ${v2_source} -o ${v2_binary}')
    if build_res.exit_code != 0 {
        eprintln('Error: Failed to build v2')
        eprintln(build_res.output)
        exit(1)
    }

    // Find all test files (*.v except run_tests.v).
    test_files := os.ls(tests_dir) or {
        eprintln('Error: Cannot list tests directory')
        exit(1)
    }

    mut passed := 0
    mut failed := 0
    mut test_count := 0

    for file in test_files {
        if !file.ends_with('.v') || file == 'run_tests.v' {
            continue
        }
        test_count++
        test_path := os.join_path(tests_dir, file)
        test_name := file.replace('.v', '')

        println('\n[*] Testing: ${file}')

        // Run v2 with cleanc backend.
        v2_output := os.join_path(tests_dir, 'test_${test_name}')
        v2_cmd := '${v2_binary} -gc none -backend cleanc ${test_path} -o ${v2_output}'
        v2_res := os.execute(v2_cmd)
        if v2_res.exit_code != 0 {
            eprintln('  [FAIL] v2 compilation failed')
            eprintln(v2_res.output)
            failed++
            continue
        }

        // Run the generated binary.
        gen_res := os.execute(v2_output)
        if gen_res.exit_code != 0 {
            eprintln('  [FAIL] Generated binary exited with code ${gen_res.exit_code}')
            eprintln(gen_res.output)
            failed++
            continue
        }

        // Run reference compiler (v1).
        ref_res := os.execute('${@VEXE} -gc none -n -w -enable-globals run ${test_path}')
        if ref_res.exit_code != 0 {
            eprintln('  [FAIL] Reference compilation failed')
            eprintln(ref_res.output)
            failed++
            continue
        }

        // Compare outputs.
        expected := ref_res.output.trim_space().replace('\r\n', '\n')
        actual := gen_res.output.trim_space().replace('\r\n', '\n')

        if expected == actual {
            println('  [PASS] Output matches reference')
            passed++
        } else {
            println('  [FAIL] Output mismatch')
            println('  Expected:\n${expected}')
            println('  Got:\n${actual}')
            failed++
        }

        // Clean up.
        os.rm(v2_output) or {}
        os.rm('${v2_output}.c') or {}
    }

    println('\n========================================')
    println('Results: ${passed}/${test_count} tests passed')
    if failed > 0 {
        println('${failed} tests FAILED')
        exit(1)
    }
    println('Total time: ${time.since(t0)}')
}