module main

import os
import os.cmdline
import testing
import v.pref

struct Context {
mut:
    verbose   bool
    fail_fast bool
    run_only  []string
}

fn main() {
    args := os.args.clone()
    if os.args.last() == 'test' {
        show_usage()
        return
    }
    args_to_executable := args[1..]
    mut args_before := cmdline.options_before(args_to_executable, ['test'])
    mut args_after := cmdline.options_after(args_to_executable, ['test'])
    mut ctx := Context{}
    ctx.fail_fast = extract_flag_bool('-fail-fast', mut args_after, testing.fail_fast)
    ctx.verbose = extract_flag_bool('-v', mut args_after, false)
    ctx.run_only = extract_flag_string_array('-run-only', mut args_after, testing.test_only_fn)
    os.setenv('VTEST_ONLY_FN', ctx.run_only.join(','), true)
    if args_after == ['v'] {
        eprintln('`v test v` has been deprecated.')
        eprintln('Use `v test-all` instead.')
        exit(1)
    }
    backend_pos := args_before.index('-b')
    backend := if backend_pos == -1 { '.c' } else { args_before[backend_pos + 1] }

    mut ts := testing.new_test_session(args_before.join(' '), true)
    ts.exec_mode = .compile_and_run
    ts.fail_fast = ctx.fail_fast
    for targ in args_after {
        if os.is_dir(targ) {
            // Fetch all tests from the directory
            files, skip_files := ctx.should_test_dir(targ.trim_right(os.path_separator), backend)
            ts.files << files
            ts.skip_files << skip_files
            continue
        } else if os.exists(targ) {
            match ctx.should_test(targ, backend) {
                .test {
                    ts.files << targ
                    continue
                }
                .skip {
                    if ctx.run_only.len > 0 {
                        continue
                    }
                    ts.files << targ
                    ts.skip_files << os.abs_path(targ)
                    continue
                }
                .ignore {}
            }
        } else {
            eprintln('\nUnrecognized test file `${targ}`.\n `v test` can only be used with folders and/or _test.v files.\n')
            show_usage()
            exit(1)
        }
    }
    ts.session_start('Testing...')
    ts.test()
    ts.session_stop('all V _test.v files')
    if ts.failed_cmds.len > 0 {
        exit(1)
    }
}

fn show_usage() {
    println('Usage:')
    println('   A)')
    println('      v test folder/ : run all v tests in the given folder.')
    println('      v -stats test folder/ : the same, but print more stats.')
    println('   B)')
    println('      v test file_test.v : run test functions in a given test file.')
    println('      v -stats test file_test.v : as above, but with more stats.')
    println('   Note: you can also give many and mixed folder/ file_test.v arguments after `v test` .')
    println('')
}

pub fn (mut ctx Context) should_test_dir(path string, backend string) ([]string, []string) { // return is (files, skip_files)
    mut files := os.ls(path) or { return []string{}, []string{} }
    mut local_path_separator := os.path_separator
    if path.ends_with(os.path_separator) {
        local_path_separator = ''
    }
    mut res_files := []string{}
    mut skip_files := []string{}
    for file in files {
        p := path + local_path_separator + file
        if os.is_dir(p) && !os.is_link(p) {
            if file == 'testdata' {
                continue
            }
            ret_files, ret_skip_files := ctx.should_test_dir(p, backend)
            res_files << ret_files
            skip_files << ret_skip_files
        } else if os.exists(p) {
            match ctx.should_test(p, backend) {
                .test {
                    res_files << p
                }
                .skip {
                    if ctx.run_only.len > 0 {
                        continue
                    }
                    res_files << p
                    skip_files << os.abs_path(p)
                }
                .ignore {}
            }
        }
    }
    return res_files, skip_files
}

enum ShouldTestStatus {
    test   // do test, print OK or FAIL, depending on if it passes
    skip   // print SKIP for the test
    ignore // just ignore the file, so it will not be printed at all in the list of tests
}

fn (mut ctx Context) should_test(path string, backend string) ShouldTestStatus {
    if path.ends_with('_test.v') {
        return ctx.should_test_when_it_contains_matching_fns(path, backend)
    }
    if path.ends_with('_test.c.v') {
        return ctx.should_test_when_it_contains_matching_fns(path, backend)
    }
    if path.ends_with('_test.js.v') {
        if testing.is_node_present {
            return ctx.should_test_when_it_contains_matching_fns(path, backend)
        }
        return .skip
    }
    // `_test.vv2` files are v2-only integration tests. They are full V programs
    // (with `main()`) that exercise v2-specific syntax; the test runner routes
    // them through the v2 binary instead of v1. Honor `-run-only` so targeted
    // runs do not pull in unrelated vv2 tests.
    if path.ends_with('_test.vv2') {
        return ctx.should_test_when_it_contains_matching_fns(path, backend)
    }
    if path.ends_with('.v') && path.count('.') == 2 {
        if !path.all_before_last('.v').all_before_last('.').ends_with('_test') {
            return .ignore
        }
        backend_arg := path.all_before_last('.v').all_after_last('.')
        arch := pref.arch_from_string(backend_arg) or { pref.Arch._auto }
        if arch == pref.get_host_arch() {
            return ctx.should_test_when_it_contains_matching_fns(path, backend)
        } else if arch == ._auto {
            if backend_arg == 'c' { // .c.v
                return if backend == 'c' {
                    ctx.should_test_when_it_contains_matching_fns(path, backend)
                } else {
                    ShouldTestStatus.skip
                }
            }
            if backend_arg == 'js' {
                return if backend == 'js' {
                    ctx.should_test_when_it_contains_matching_fns(path, backend)
                } else {
                    ShouldTestStatus.skip
                }
            }
        } else {
            return .skip
        }
    }
    return .ignore
}

fn (mut ctx Context) should_test_when_it_contains_matching_fns(path string, _backend string) ShouldTestStatus {
    if ctx.run_only.len == 0 {
        // no filters set, so just compile and test
        return .test
    }
    lines := os.read_lines(path) or { return .ignore }
    for line in lines {
        if line.match_glob('fn test_*') || line.match_glob('pub fn test_*') {
            tname := line.replace_each(['pub fn ', '', 'fn ', '']).all_before('(')
            for pattern in ctx.run_only {
                mut pat := pattern.clone()
                if pat.contains('.') {
                    pat = pat.all_after_last('.')
                }
                if tname.match_glob(pat) {
                    if ctx.verbose {
                        println('> compiling path: ${path}, since test fn `${tname}` matches glob pattern `${pat}`')
                    }
                    return .test
                }
            }
        }
    }
    return .ignore
}

fn extract_flag_bool(flag_name string, mut after []string, flag_default bool) bool {
    mut res := flag_default
    orig_after :=
        after.clone() // workaround for after.filter() codegen bug, when `mut after []string`
    matches_after := orig_after.filter(it != flag_name)
    if matches_after.len < after.len {
        after = matches_after.clone()
        res = true
    }
    return res
}

fn extract_flag_string_array(flag_name string, mut after []string, flag_default []string) []string {
    mut res := flag_default.clone()
    mut found := after.index(flag_name)
    if found > -1 {
        if found + 1 < after.len {
            res = after[found + 1].split_any(',')
            after.delete(found)
        }
        after.delete(found)
    }
    return res
}