from stdint import *
import stdio
import stdlib
import string
import viperlib
import os
import os.path
import win32.win32base
import win32.win32file
import win32.win32process
import lib.Phase.BuildPipeline as BuildPipeline


define SELF_EXE_CAP = 4096
define SELF_BUILD_DIR = "__vpcbuild_2__"
define COPY_DELAY_SECONDS = 5


def _GetSelfExe() -> str:
    buf: bytes = stdlib.malloc(sizet(SELF_EXE_CAP))
    if buf is None:
        return None
    n: uint32 = win32.win32file.GetModuleFileNameA(None, buf, uint32(SELF_EXE_CAP))
    if int(n) <= 0:
        stdlib.free(buf)
        return None
    ni: int = int(n)
    if ni >= SELF_EXE_CAP:
        ni = SELF_EXE_CAP - 1
    buf[ni] = 0
    return str(buf)


def _TryRoot(dir: str) -> str:
    if dir is None or len(dir) == 0:
        return None
    root: str = os.path.normpath(dir)
    if root is None:
        return None
    project: str = os.path.join(root, "project.vpj")
    copyself_project: str = os.path.join(os.path.join(root, "copyself"), "project.vpj")
    if project is not None and copyself_project is not None:
        if os.isfile(project) and os.isfile(copyself_project):
            return root
    return None


def _FindViperCRoot(self_exe: str) -> str:
    base: str = os.path.dirname(self_exe)
    if base is None:
        base = ""
    parent1: str = os.path.dirname(base)
    parent2: str = os.path.dirname(parent1)

    # Executable-derived candidates first: cwd is normally the workspace root,
    # not the compiler tree.
    root: str = _TryRoot(base)
    if root is not None:
        return root
    root = _TryRoot(parent1)
    if root is not None:
        return root
    root = _TryRoot(parent2)
    if root is not None:
        return root
    root = _TryRoot(os.path.join(base, "ViperC"))
    if root is not None:
        return root
    root = _TryRoot(os.path.join(base, "../ViperC"))
    if root is not None:
        return root
    root = _TryRoot(os.path.join(base, "../../ViperC"))
    if root is not None:
        return root

    # Fallback only when the executable is detached from the compiler tree.
    cwd: str = os.getcwd()
    root = _TryRoot(cwd)
    if root is not None:
        return root
    if cwd is not None:
        root = _TryRoot(os.path.join(cwd, "ViperC"))
        if root is not None:
            return root
        root = _TryRoot(os.path.join(os.path.dirname(cwd), "ViperC"))
        if root is not None:
            return root
    return None


def CollectForwardedArgs(argc: int, argv: str*) -> str:
    """--build-self: argv minus --build-self / --project / --build-dir (and their values).

    No whitelist: any current or future flag is forwarded verbatim, so a self-build can
    enable the same modes as a normal build (e.g. `viperc --build-self --spend-file p.txt
    --vpf 3`). The three excluded entries are the ones the self-build invocation owns.
    """
    if argv is None or argc <= 1: return ""
    total: sizet = 1
    i: int = 1
    while i < argc:
        a: str = argv[i]
        if a is not None:
            if string.strcmp(a, "--build-self") == 0:
                i += 1
                continue
            if string.strcmp(a, "--project") == 0 or string.strcmp(a, "--build-dir") == 0:
                i += 2
                continue
            total += len(a) + 1
        i += 1
    buf: str = stdlib.malloc(total + 1)
    if buf is None: return ""
    buf[0] = '\0'
    i = 1
    while i < argc:
        a2: str = argv[i]
        if a2 is not None:
            if string.strcmp(a2, "--build-self") == 0:
                i += 1
                continue
            if string.strcmp(a2, "--project") == 0 or string.strcmp(a2, "--build-dir") == 0:
                i += 2
                continue
            if buf[0] != '\0': string.strcat(buf, " ")
            string.strcat(buf, a2)
        i += 1
    return buf


def _FormatSelfBuildCommand(self_exe: str, project: str, build_dir: str, extra: str) -> str:
    # `extra` is the caller's forwarded argument string (empty when nothing was forwarded):
    # the rebuilt compiler then carries exactly the modes the user asked for.
    extra_len: sizet = 0
    if extra is not None: extra_len = len(extra)
    need: sizet = len(self_exe) + len(project) + len(build_dir) + extra_len + 64
    buf: bytes = stdlib.malloc(need)
    if buf is None:
        return None
    viperlib.snprintf(buf, need, "\"%s\" --project \"%s\" --clean --build-dir \"%s\"",
                      self_exe, project, build_dir)
    if extra is not None and extra_len > 0:
        pos: sizet = string.strlen(str(buf))
        viperlib.snprintf(buf + pos, need - pos, " %s", extra)
    return str(buf)


def _FindCopySelfExe(root: str) -> str:
    base: str = os.path.join(root, "copyself")
    standard: str = os.path.join(os.path.join(os.path.join(base, "__vpcbuild__"), "output"), "copyself.exe")
    if os.isfile(standard):
        return standard
    legacy: str = os.path.join(os.path.join(base, "output"), "copyself.exe")
    if os.isfile(legacy):
        return legacy
    return None


def _FormatCopySelfCommand(copyself_exe: str) -> str:
    need: sizet = len(copyself_exe) + 128
    buf: bytes = stdlib.malloc(need)
    if buf is None:
        return None
    viperlib.snprintf(buf, need, "\"%s\" %d ../../__vpcbuild_2__ ../../__vpcbuild__",
                      copyself_exe, COPY_DELAY_SECONDS)
    return str(buf)


def _SpawnDetached(cmd: str, cwd: str) -> int:
    if cmd is None or cwd is None:
        stdio.printf("FAIL: --build-self cannot launch copyself without a command and working directory\n")
        return -1
    clen: sizet = len(cmd)
    cmd_line: bytes = stdlib.malloc(clen + 1)
    if cmd_line is None:
        stdio.printf("FAIL: --build-self failed to allocate the copyself command line\n")
        return -1
    string.strcpy(cmd_line, cmd)

    si: win32.win32process.STARTUPINFOA = win32.win32process.STARTUPINFOA()
    pi: win32.win32process.PROCESS_INFORMATION = win32.win32process.PROCESS_INFORMATION()
    string.memset(&si, 0, win32.win32process.STARTUPINFOA.__sizeof__())
    string.memset(&pi, 0, win32.win32process.PROCESS_INFORMATION.__sizeof__())
    si.cb = win32.win32process.STARTUPINFOA.__sizeof__()

    ok: int = win32.win32process.CreateProcessA(None, cmd_line, None, None, 1, 0,
                                                 None, cwd, &si, &pi)
    if ok == 0:
        err: uint32 = win32.win32base.GetLastError()
        stdio.printf("FAIL: --build-self could not launch copyself (Win32 error %d)\n", int(err))
        stdio.printf("  command: %s\n", cmd)
        stdlib.free(cmd_line)
        return -1

    stdio.printf("build-self: copyself launched (pid=%d)\n", int(pi.dwProcessId))
    win32.win32base.CloseHandle(pi.hProcess)
    win32.win32base.CloseHandle(pi.hThread)
    stdlib.free(cmd_line)
    return 0


# _SelfExeDir - directory containing the running compiler ("D:/x/viperc.exe" -> "D:/x").
def _SelfExeDir(self_exe: str) -> str:
    if self_exe is None: return None
    n: sizet = string.strlen(self_exe)
    cut: sizet = n
    while cut > 0:
        ch: char = self_exe[cut - 1]
        if ch == '\\' or ch == '/':
            cut -= 1
            break
        cut -= 1
    if cut >= n: return None
    out: str = stdlib.malloc(cut + 1)
    if out is None: return None
    if cut > 0: string.strncpy(out, self_exe, cut)
    out[cut] = '\0'
    return out


# _CrashHint - name the common NTSTATUS exit codes. The child inherits the parent console, so
# its own output is already visible; these codes are raised as fail-fast and carry no SEH
# exception, which is why a traceback handler inside the child cannot print a stack.
def _CrashHint(rc: int) -> None:
    u: uint32 = uint32(rc)
    if u == uint32(0xC0000005):
        stdio.printf("  child crashed: access violation (0xC0000005)\n")
    elif u == uint32(0xC0000374):
        stdio.printf("  child crashed: heap corruption (0xC0000374) -- fail-fast, no SEH traceback\n")
    elif u == uint32(0xC00000FD):
        stdio.printf("  child crashed: stack overflow (0xC00000FD)\n")
    elif u == uint32(0xC0000409):
        stdio.printf("  child crashed: fail-fast / security check (0xC0000409)\n")


def RunSelfBuild(extra: str) -> int:
    self_exe: str = _GetSelfExe()
    if self_exe is None:
        stdio.printf("FAIL: --build-self could not resolve the compiler executable path\n")
        return 1
    root: str = _FindViperCRoot(self_exe)
    if root is None:
        stdio.printf("FAIL: --build-self could not locate the ViperC root\n")
        stdio.printf("  expected both: project.vpj and copyself/project.vpj\n")
        return 1

    project: str = os.path.join(root, "project.vpj")
    build_dir: str = os.path.join(root, SELF_BUILD_DIR)
    copyself_exe: str = _FindCopySelfExe(root)
    if copyself_exe is None:
        stdio.printf("FAIL: copyself.exe not found under %s\n", os.path.join(root, "copyself"))
        stdio.printf("  expected: output/copyself.exe or __vpcbuild__/output/copyself.exe\n")
        stdio.printf("  build it first: viperc --project %s --clean\n",
                     os.path.join(os.path.join(root, "copyself"), "project.vpj"))
        return 1

    cmd: str = _FormatSelfBuildCommand(self_exe, project, build_dir, extra)
    if cmd is None:
        stdio.printf("FAIL: --build-self failed to build the compiler command line\n")
        return 1
    stdio.printf("build-self: %s\n", cmd)
    rc: int = BuildPipeline._run_cmd_wait(cmd)
    if rc != 0:
        stdio.printf("FAIL: --build-self compilation failed (exit=%d)\n", rc)
        _CrashHint(rc)
        return 1

    built_exe: str = os.path.join(os.path.join(build_dir, "output"), "viperc.exe")
    if not os.isfile(built_exe):
        stdio.printf("FAIL: --build-self did not produce %s\n", built_exe)
        return 1

    # The requested arguments are relative to ViperC/copyself/output. Use that
    # directory as the launch cwd even when copyself.exe lives under
    # copyself/__vpcbuild__/output.
    copyself_cwd: str = os.path.join(os.path.join(root, "copyself"), "output")
    if not os.isdir(copyself_cwd):
        if os.mkdir(copyself_cwd) != 0:
            if not os.isdir(copyself_cwd):
                err_mkdir: ULONG = win32.win32base.GetLastError()
                stdio.printf("FAIL: --build-self could not create %s (Win32 error %d)\n",
                             copyself_cwd, int(err_mkdir))
                return 1
    # copyself replaces ViperC\__vpcbuild__ wholesale, so everything the compiler needs next to
    # viperc.exe must be in the new output directory *before* the copy runs. ircore.dll is the
    # important one: without it every PhaseB module silently falls back to spawning
    # mlir-opt/mlir-translate/llc (3 processes per module), which is both slower and a
    # different code path than the one being profiled.
    self_dir: str = _SelfExeDir(self_exe)
    if self_dir is not None:
        src_dll: str = os.path.join(self_dir, "ircore.dll")
        dst_dll: str = os.path.join(os.path.join(build_dir, "output"), "ircore.dll")
        if os.isfile(src_dll) and not os.isfile(dst_dll):
            cop: BOOL = win32.win32file.CopyFileA(src_dll, dst_dll, 0)
            if cop == 0:
                stdio.printf("build-self: warning: could not copy ircore.dll next to the new viperc.exe\n")
            else:
                stdio.printf("build-self: copied ircore.dll into the new output directory\n")

    copy_cmd: str = _FormatCopySelfCommand(copyself_exe)
    if copy_cmd is None:
        stdio.printf("FAIL: --build-self failed to build the copyself command line\n")
        return 1
    if _SpawnDetached(copy_cmd, copyself_cwd) != 0:
        return 1
    stdio.printf("build-self: __vpcbuild__ will be replaced after %d seconds\n", COPY_DELAY_SECONDS)
    return 0