import os
import time
import term
import v.util.version
import runtime
import encoding.iconv

struct App {
mut:
    report_lines   []string
    cached_cpuinfo map[string]string
    vexe           string
}

fn (mut a App) println(s string) {
    a.report_lines << s
}

fn (mut a App) collect_info() {
    a.line('V full version', version.full_v_version(true))
    a.line(':-------------------', ':-------------------')

    mut os_kind := os.user_os()
    mut arch_details := []string{}
    arch_details << '${runtime.nr_cpus()} cpus'
    if runtime.is_32bit() {
        arch_details << '32bit'
    }
    if runtime.is_64bit() {
        arch_details << '64bit'
    }
    if runtime.is_big_endian() {
        arch_details << 'big endian'
    }
    if runtime.is_little_endian() {
        arch_details << 'little endian'
    }
    if os_kind == 'macos' {
        arch_details << a.cmd(command: 'sysctl -n machdep.cpu.brand_string')
    }
    if os_kind == 'linux' {
        mut cpu_details := ''
        if cpu_details == '' {
            cpu_details = a.cpu_info('model name')
        }
        if cpu_details == '' {
            cpu_details = a.cpu_info('hardware')
        }
        if cpu_details == '' {
            cpu_details = os.uname().machine
        }
        arch_details << cpu_details
    }
    if os_kind == 'windows' {
        arch_details << a.cmd(
            command: 'wmic cpu get name /format:table'
            line:    2
        )
    }

    mut os_details := ''
    wsl_check := a.cmd(command: 'cat /proc/sys/kernel/osrelease')
    if os_kind == 'linux' {
        os_details = a.get_linux_os_name()
        if a.cpu_info('flags').contains('hypervisor') {
            if wsl_check.contains('microsoft') {
                // WSL 2 is a Managed VM and Full Linux Kernel
                // See https://docs.microsoft.com/en-us/windows/wsl/compare-versions
                os_details += ' (WSL 2)'
            } else {
                os_details += ' (VM)'
            }
        }
        // WSL 1 is NOT a Managed VM and Full Linux Kernel
        // See https://docs.microsoft.com/en-us/windows/wsl/compare-versions
        if wsl_check.contains('Microsoft') {
            os_details += ' (WSL)'
        }
        // From https://unix.stackexchange.com/a/14346
        awk_cmd := '[ "$(awk \'\$5=="/" {print \$1}\' </proc/1/mountinfo)" != "$(awk \'\$5=="/" {print \$1}\' </proc/$$/mountinfo)" ] ; echo \$?'
        if a.cmd(command: awk_cmd) == '0' {
            os_details += ' (chroot)'
        }
    } else if os_kind == 'macos' {
        mut details := []string{}
        details << a.cmd(command: 'sw_vers -productName')
        details << a.cmd(command: 'sw_vers -productVersion')
        details << a.cmd(command: 'sw_vers -buildVersion')
        os_details = details.join(', ')
    } else if os_kind == 'windows' {
        wmic_info := a.cmd(
            command: 'wmic os get * /format:value'
            line:    -1
        )
        p := a.parse(wmic_info, '=')
        mut caption, mut build_number, mut os_arch := p['caption'], p['buildnumber'], p['osarchitecture']
        caption = iconv.encoding_to_vstring(caption.bytes(), 'ANSI') or { caption }
        build_number = iconv.encoding_to_vstring(build_number.bytes(), 'ANSI') or { build_number }
        os_arch = iconv.encoding_to_vstring(os_arch.bytes(), 'ANSI') or { os_arch }
        os_details = '${caption} ${build_number} ${os_arch}'
    } else {
        ouname := os.uname()
        os_details = '${ouname.release}, ${ouname.version}'
    }
    a.line('OS', '${os_kind}, ${os_details}')
    a.line('Processor', arch_details.join(', '))
    total_memory := f32(runtime.total_memory() or { 0 }) / (1024.0 * 1024.0 * 1024.0)
    free_memory := f32(runtime.free_memory() or { 0 }) / (1024.0 * 1024.0 * 1024.0)
    if total_memory != 0 && free_memory != 0 {
        a.line('Memory', '${free_memory:.2}GB/${total_memory:.2}GB')
    } else {
        a.line('Memory', 'N/A')
    }

    a.line('', '')
    vexe := a.vexe
    vroot := os.dir(vexe)
    vmodules := os.vmodules_dir()
    vtmp_dir := os.vtmp_dir()
    getwd := os.getwd()
    os.chdir(vroot) or {}
    a.line('V executable', vexe)
    a.line('V last modified time', time.unix(os.file_last_mod_unix(vexe)).str())
    a.line('', '')
    a.line2('V home dir', diagnose_dir(vroot), vroot)
    a.line2('VMODULES', diagnose_dir(vmodules), vmodules)
    a.line2('VTMP', diagnose_dir(vtmp_dir), vtmp_dir)
    a.line2('Current working dir', diagnose_dir(getwd), getwd)
    a.line('', '')

    a.line_env('VFLAGS')
    a.line_env('CFLAGS')
    a.line_env('LDFLAGS')

    a.line('Git version', a.cmd(command: 'git --version'))
    a.line('V git status', a.git_info())
    a.line('.git/config present', os.is_file('.git/config').str())
    a.line('', '')
    a.line('cc version', a.cmd(command: 'cc --version'))
    if os_kind == 'openbsd' {
        a.line('gcc version', a.cmd(command: 'egcc --version'))
    } else {
        a.line('gcc version', a.cmd(command: 'gcc --version'))
    }
    a.line('clang version', a.cmd(command: 'clang --version'))
    if os_kind == 'windows' {
        // Check for MSVC on windows
        a.line('msvc version', a.cmd(command: 'cl'))
    }
    a.report_tcc_version('thirdparty/tcc')
    a.line('emcc version', a.cmd(command: 'emcc --version'))
    if os_kind != 'openbsd' && os_kind != 'freebsd' {
        a.line('glibc version', a.cmd(command: 'ldd --version'))
    } else {
        a.line('glibc version', 'N/A')
    }
}

struct CmdConfig {
    line    int
    command string
}

fn (mut a App) cmd(c CmdConfig) string {
    x := os.execute(c.command)
    os_kind := os.user_os()
    if x.exit_code < 0 || x.exit_code == 127 || (os_kind == 'windows' && x.exit_code == 1) {
        return 'N/A'
    }
    if x.exit_code == 0 {
        if c.line < 0 {
            return x.output
        }
        output := x.output.split_into_lines()
        if output.len > 0 && output.len > c.line {
            return output[c.line]
        }
    }
    return 'Error: ${x.output}'
}

fn (mut a App) line(label string, value string) {
    a.println('|${label:-20}|${term.colorize(term.bold, value)}')
}

fn (mut a App) line2(label string, value string, value2 string) {
    a.println('|${label:-20}|${term.colorize(term.bold, value)}, value: ${term.colorize(term.bold,
        value2)}')
}

fn (mut a App) line_env(env_var string) {
    value := os.getenv(env_var)
    if value != '' {
        a.line('env ${env_var}', '"${value}"')
    }
}

fn (app &App) parse(config string, sep string) map[string]string {
    mut m := map[string]string{}
    lines := config.split_into_lines()
    for line in lines {
        sline := line.trim_space()
        if sline.len == 0 || sline[0] == `#` {
            continue
        }
        x := sline.split(sep)
        if x.len < 2 {
            continue
        }
        m[x[0].trim_space().to_lower()] = x[1].trim_space().trim('"')
    }
    return m
}

fn (mut a App) get_linux_os_name() string {
    if os.is_file('/etc/os-release') {
        if lines := os.read_file('/etc/os-release') {
            vals := a.parse(lines, '=')
            if vals['PRETTY_NAME'] != '' {
                return vals['PRETTY_NAME']
            }
        }
    }
    if !a.cmd(command: 'type lsb_release').starts_with('Error') {
        return a.cmd(command: 'lsb_release -d -s')
    }
    if os.is_file('/proc/version') {
        return a.cmd(command: 'cat /proc/version')
    }
    ouname := os.uname()
    return '${ouname.release}, ${ouname.version}'
}

fn (mut a App) cpu_info(key string) string {
    if a.cached_cpuinfo.len > 0 {
        return a.cached_cpuinfo[key]
    }
    info := os.execute('cat /proc/cpuinfo')
    if info.exit_code != 0 {
        return '`cat /proc/cpuinfo` could not run'
    }
    a.cached_cpuinfo = a.parse(info.output, ':')
    return a.cached_cpuinfo[key]
}

fn (mut a App) git_info() string {
    // Check if in a Git repository
    x := os.execute('git rev-parse --is-inside-work-tree')
    if x.exit_code != 0 || x.output.trim_space() != 'true' {
        return 'N/A'
    }
    mut out := a.cmd(command: 'git -C . describe --abbrev=8 --dirty --always --tags').trim_space()
    os.execute('git -C . remote add V_REPO https://github.com/vlang/v') // ignore failure (i.e. remote exists)
    if '-skip-github' !in os.args {
        os.execute('${os.quoted_path(a.vexe)} timeout 5.1 "git -C . fetch V_REPO"') // usually takes ~0.6s; 5 seconds should be enough for even the slowest networks
    }
    commit_count := a.cmd(command: 'git rev-list @{0}...V_REPO/master --right-only --count').int()
    if commit_count > 0 {
        out += ' (${commit_count} commit(s) behind V master)'
    }
    return out
}

fn (mut a App) report_tcc_version(tccfolder string) {
    cmd := os.join_path(tccfolder, 'tcc.exe') + ' -v'
    x := os.execute(cmd)
    if x.exit_code == 0 {
        a.line('tcc version', '${x.output.trim_space()}')
    } else {
        a.line('tcc version', 'N/A')
    }
    if !os.is_file(os.join_path(tccfolder, '.git', 'config')) {
        a.line('tcc git status', 'N/A')
    } else {
        tcc_branch_name := a.cmd(
            command: 'git -C ${os.quoted_path(tccfolder)} rev-parse --abbrev-ref HEAD'
        )
        tcc_commit := a.cmd(
            command: 'git -C ${os.quoted_path(tccfolder)} describe --abbrev=8 --dirty --always --tags'
        )
        a.line('tcc git status', '${tcc_branch_name} ${tcc_commit}')
    }
}

fn (mut a App) report_info() {
    for x in a.report_lines {
        println(x)
    }
}

fn is_writable_dir(path string) bool {
    os.ensure_folder_is_writable(path) or { return false }
    return true
}

fn diagnose_dir(path string) string {
    mut diagnostics := []string{}
    if !is_writable_dir(path) {
        diagnostics << 'NOT writable'
    }
    if path.contains(' ') {
        diagnostics << 'contains spaces'
    }
    path_non_ascii_runes := path.runes().filter(it > 255)
    if path_non_ascii_runes.len > 0 {
        diagnostics << 'contains these non ASCII characters: ${path_non_ascii_runes}'
    }
    if diagnostics.len == 0 {
        diagnostics << 'OK'
    }
    return diagnostics.join(', ')
}

fn main() {
    mut app := App{}
    app.vexe = os.getenv('VEXE')
    app.collect_info()
    app.report_info()
}