import os
import rand
import term
import v.util.diff
import v.util.vtest
import time
import runtime
import benchmark

const skip_files = [
    'non_existing.vv', // minimize commit diff churn, do not remove
]

const skip_on_cstrict = [
    'vlib/v/checker/tests/missing_c_lib_header_1.vv',
    'vlib/v/checker/tests/missing_c_lib_header_with_explanation_2.vv',
]

const skip_on_ubuntu_musl = [
    'vlib/v/checker/tests/vweb_tmpl_used_var.vv',
    'vlib/v/checker/tests/vweb_routing_checks.vv',
    'vlib/v/tests/skip_unused/gg_code.vv',
]

const skip_on_ci_musl = [
    'vlib/v/tests/skip_unused/gg_code.vv',
]

const vexe = os.getenv('VEXE')

const turn_off_vcolors = os.setenv('VCOLORS', 'never', true)

const show_cmd = os.getenv('VTEST_SHOW_CMD') != ''

// This is needed, because some of the .vv files are tests, and we do need stable
// output from them, that can be compared against their .out files:
const turn_on_normal_test_runner = os.setenv('VTEST_RUNNER', 'normal', true)

const should_autofix = os.getenv('VAUTOFIX') != ''

const github_job = os.getenv('GITHUB_JOB')

const v_ci_ubuntu_musl = os.getenv('V_CI_UBUNTU_MUSL').len > 0

const v_ci_musl = os.getenv('V_CI_MUSL').len > 0

const v_ci_cstrict = os.getenv('V_CI_CSTRICT').len > 0

struct TaskDescription {
    vexe             string
    evars            string
    dir              string
    voptions         string
    result_extension string
    path             string
mut:
    is_error          bool
    is_skipped        bool
    is_module         bool
    expected          string
    expected_out_path string
    found___          string
    took              time.Duration
    cli_cmd           string
}

struct Tasks {
    vexe          string
    parallel_jobs int // 0 is using VJOBS, anything else is an override
    label         string
mut:
    show_cmd bool
    all      []TaskDescription
}

fn test_all() {
    vroot := os.dir(vexe)
    os.chdir(vroot) or {}
    checker_dir := 'vlib/v/checker/tests'
    checker_with_check_option_dir := 'vlib/v/checker/tests/with_check_option'
    parser_dir := 'vlib/v/parser/tests'
    scanner_dir := 'vlib/v/scanner/tests'
    module_dir := '${checker_dir}/modules'
    global_dir := '${checker_dir}/globals'
    global_run_dir := '${checker_dir}/globals_run'
    run_dir := '${checker_dir}/run'
    skip_unused_dir := 'vlib/v/tests/skip_unused'
    //
    checker_tests := get_tests_in_dir(checker_dir, false).filter(!it.contains('with_check_option'))
    parser_tests := get_tests_in_dir(parser_dir, false)
    scanner_tests := get_tests_in_dir(scanner_dir, false)
    global_tests := get_tests_in_dir(global_dir, false)
    global_run_tests := get_tests_in_dir(global_run_dir, false)
    module_tests := get_tests_in_dir(module_dir, true)
    run_tests := get_tests_in_dir(run_dir, false)
    skip_unused_dir_tests := get_tests_in_dir(skip_unused_dir, false)
    checker_with_check_option_tests := get_tests_in_dir(checker_with_check_option_dir,
        false)
    mut tasks := Tasks{
        vexe: vexe
        label: 'all tests'
    }
    tasks.add('', parser_dir, '', '.out', parser_tests, false)
    tasks.add('', checker_dir, '', '.out', checker_tests, false)
    tasks.add('', scanner_dir, '', '.out', scanner_tests, false)
    tasks.add('', checker_dir, '-enable-globals run', '.run.out', ['globals_error.vv'],
        false)
    tasks.add('', global_run_dir, '-enable-globals run', '.run.out', global_run_tests,
        false)
    tasks.add('', global_dir, '-enable-globals', '.out', global_tests, false)
    tasks.add('', module_dir, '-prod run', '.out', module_tests, true)
    tasks.add('', run_dir, 'run', '.run.out', run_tests, false)
    tasks.add('', checker_with_check_option_dir, '-check', '.out', checker_with_check_option_tests,
        false)
    tasks.run()
    //
    if os.user_os() == 'linux' {
        mut skip_unused_tasks := Tasks{
            vexe: vexe
            parallel_jobs: 1
            label: '-skip-unused tests'
        }
        skip_unused_tasks.add('', skip_unused_dir, 'run', '.run.out', skip_unused_dir_tests,
            false)
        skip_unused_tasks.add('', skip_unused_dir, '-d no_backtrace -skip-unused run',
            '.skip_unused.run.out', skip_unused_dir_tests, false)
        skip_unused_tasks.run()
    }
    //
    if github_job == 'ubuntu-tcc' {
        // This is done with tcc only, because the error output is compiler specific.
        // Note: the tasks should be run serially, since they depend on
        // setting and using environment variables.
        mut cte_tasks := Tasks{
            vexe: vexe
            parallel_jobs: 1
            label: 'comptime env tests'
        }
        cte_dir := '${checker_dir}/comptime_env'
        files := get_tests_in_dir(cte_dir, false)
        cte_tasks.add('', cte_dir, '-no-retry-compilation run', '.run.out', files, false)
        cte_tasks.add_evars('VAR=/usr/include', '', cte_dir, '-no-retry-compilation run',
            '.var.run.out', ['using_comptime_env.vv'], false)
        cte_tasks.add_evars('VAR=/opt/invalid/path', '', cte_dir, '-no-retry-compilation run',
            '.var_invalid.run.out', ['using_comptime_env.vv'], false)
        cte_tasks.run()
    }
    mut ct_tasks := Tasks{
        vexe: vexe
        parallel_jobs: 1
        label: 'comptime define tests'
    }
    ct_tasks.add_checked_run('-d mysymbol run', '.mysymbol.run.out', [
        'custom_comptime_define_error.vv',
    ])
    ct_tasks.add_checked_run('-d mydebug run', '.mydebug.run.out', [
        'custom_comptime_define_if_flag.vv',
    ])
    ct_tasks.add_checked_run('-d nodebug run', '.nodebug.run.out', [
        'custom_comptime_define_if_flag.vv',
    ])
    ct_tasks.add_checked_run('run', '.run.out', ['custom_comptime_define_if_debug.vv'])
    ct_tasks.add_checked_run('-g run', '.g.run.out', [
        'custom_comptime_define_if_debug.vv',
    ])
    ct_tasks.add_checked_run('-cg run', '.cg.run.out', [
        'custom_comptime_define_if_debug.vv',
    ])
    ct_tasks.add_checked_run('-d debug run', '.debug.run.out', [
        'custom_comptime_define_if_debug.vv',
    ])
    ct_tasks.add_checked_run('-d debug -d bar run', '.debug.bar.run.out', [
        'custom_comptime_define_if_debug.vv',
    ])
    ct_tasks.run()
}

fn (mut tasks Tasks) add_checked_run(voptions string, result_extension string, tests []string) {
    checker_dir := 'vlib/v/checker/tests'
    tasks.add('', checker_dir, voptions, result_extension, tests, false)
}

fn (mut tasks Tasks) add(custom_vexe string, dir string, voptions string, result_extension string, tests []string, is_module bool) {
    tasks.add_evars('', custom_vexe, dir, voptions, result_extension, tests, is_module)
}

fn (mut tasks Tasks) add_evars(evars string, custom_vexe string, dir string, voptions string, result_extension string, tests []string, is_module bool) {
    paths := vtest.filter_vtest_only(tests, basepath: dir)
    for path in paths {
        tasks.all << TaskDescription{
            evars: evars
            vexe: if custom_vexe != '' { custom_vexe } else { tasks.vexe }
            dir: dir
            voptions: voptions
            result_extension: result_extension
            path: path
            is_module: is_module
        }
    }
}

fn bstep_message(mut bench benchmark.Benchmark, label string, msg string, sduration time.Duration) string {
    return bench.step_message_with_label_and_duration(label, msg, sduration)
}

// process an array of tasks in parallel, using no more than vjobs worker threads
fn (mut tasks Tasks) run() {
    if tasks.all.len == 0 {
        return
    }
    tasks.show_cmd = show_cmd
    vjobs := if tasks.parallel_jobs > 0 { tasks.parallel_jobs } else { runtime.nr_jobs() }
    mut bench := benchmark.new_benchmark()
    bench.set_total_expected_steps(tasks.all.len)
    mut work := chan TaskDescription{cap: tasks.all.len}
    mut results := chan TaskDescription{cap: tasks.all.len}
    mut m_skip_files := skip_files.clone()
    if v_ci_ubuntu_musl {
        m_skip_files << skip_on_ubuntu_musl
    }
    if v_ci_musl {
        m_skip_files << skip_on_ci_musl
    }
    if v_ci_cstrict {
        m_skip_files << skip_on_cstrict
    }
    $if noskip ? {
        m_skip_files = []
    }
    $if tinyc {
        // Note: tcc does not support __has_include, so the detection mechanism
        // used for the other compilers does not work. It still provides a
        // cleaner error message, than a generic C error, but without the explanation.
        m_skip_files << 'vlib/v/checker/tests/missing_c_lib_header_1.vv'
        m_skip_files << 'vlib/v/checker/tests/missing_c_lib_header_with_explanation_2.vv'
    }
    $if msvc {
        m_skip_files << 'vlib/v/checker/tests/asm_alias_does_not_exist.vv'
        m_skip_files << 'vlib/v/checker/tests/asm_immutable_err.vv'
        // TODO: investigate why MSVC regressed
        m_skip_files << 'vlib/v/checker/tests/missing_c_lib_header_1.vv'
        m_skip_files << 'vlib/v/checker/tests/missing_c_lib_header_with_explanation_2.vv'
    }
    $if windows {
        m_skip_files << 'vlib/v/checker/tests/modules/deprecated_module'
    }
    for i in 0 .. tasks.all.len {
        if tasks.all[i].path in m_skip_files {
            tasks.all[i].is_skipped = true
        }
        work <- tasks.all[i]
    }
    work.close()
    for _ in 0 .. vjobs {
        spawn work_processor(work, results)
    }
    if github_job == '' {
        println('')
    }
    mut line_can_be_erased := true
    mut total_errors := 0
    for _ in 0 .. tasks.all.len {
        mut task := TaskDescription{}
        task = <-results
        bench.step()
        if task.is_skipped {
            bench.skip()
            eprintln(bstep_message(mut bench, benchmark.b_skip, task.path, task.took))
            line_can_be_erased = false
            continue
        }
        if task.is_error {
            total_errors++
            bench.fail()
            eprintln(bstep_message(mut bench, benchmark.b_fail, task.path, task.took))
            println('============')
            println('failed cmd: ${task.cli_cmd}')
            println('expected_out_path: ${task.expected_out_path}')
            println('============')
            println('expected:')
            println(task.expected)
            println('============')
            println('found:')
            println(task.found___)
            println('============\n')
            diff_content(task.expected, task.found___)
            line_can_be_erased = false
        } else {
            bench.ok()
            assert true
            if tasks.show_cmd {
                eprintln(bstep_message(mut bench, benchmark.b_ok, '${task.cli_cmd}', task.took))
            } else {
                if github_job == '' {
                    // local mode:
                    if line_can_be_erased {
                        term.clear_previous_line()
                    }
                    println(bstep_message(mut bench, benchmark.b_ok, task.path, task.took))
                }
            }
            line_can_be_erased = true
        }
    }
    bench.stop()
    eprintln(term.h_divider('-'))
    eprintln(bench.total_message(tasks.label))
    if total_errors != 0 {
        exit(1)
    }
}

// a single worker thread spends its time getting work from the `work` channel,
// processing the task, and then putting the task in the `results` channel
fn work_processor(work chan TaskDescription, results chan TaskDescription) {
    for {
        mut task := <-work or { break }
        sw := time.new_stopwatch()
        task.execute()
        task.took = sw.elapsed()
        results <- task
    }
}

// actual processing; Note: no output is done here at all
fn (mut task TaskDescription) execute() {
    if task.is_skipped {
        return
    }
    program := task.path
    cmd_prefix := if task.evars.len > 0 { '${task.evars} ' } else { '' }
    cli_cmd := '${cmd_prefix}${os.quoted_path(task.vexe)} ${task.voptions} ${os.quoted_path(program)}'
    res := os.execute(cli_cmd)
    expected_out_path := program.replace('.vv', '') + task.result_extension
    task.expected_out_path = expected_out_path
    task.cli_cmd = cli_cmd
    if should_autofix && !os.exists(expected_out_path) {
        os.create(expected_out_path) or { panic(err) }
    }
    mut expected := os.read_file(expected_out_path) or { panic(err) }
    task.expected = clean_line_endings(expected)
    task.found___ = clean_line_endings(res.output)
    $if windows {
        if task.is_module {
            task.found___ = task.found___.replace_once('\\', '/')
        }
    }
    if task.expected != task.found___ {
        task.is_error = true
        if should_autofix {
            os.write_file(expected_out_path, res.output) or { panic(err) }
        }
    }
}

fn clean_line_endings(s string) string {
    mut res := s.trim_space()
    res = res.replace(' \n', '\n')
    res = res.replace(' \r\n', '\n')
    res = res.replace('\r\n', '\n')
    res = res.trim('\n')
    return res
}

fn diff_content(expected string, found string) {
    diff_cmd := diff.find_working_diff_command() or { return }
    println(term.bold(term.yellow('diff: ')))
    println(diff.color_compare_strings(diff_cmd, rand.ulid(), expected, found))
    println('============\n')
}

fn get_tests_in_dir(dir string, is_module bool) []string {
    files := os.ls(dir) or { panic(err) }
    mut tests := files.clone()
    if !is_module {
        tests = files.filter(it.ends_with('.vv'))
    } else {
        tests = files.filter(!it.ends_with('.out'))
    }
    tests.sort()
    return tests
}