"""Packaged CLI entrypoint used by installers and console scripts.

This module provides the `main` entrypoint for `mm`/`medeia` and supports
running from a development checkout (by importing the top-level
`CLI.MedeiaCLI`) or when running tests that inject a legacy
`medeia_entry` shim into `sys.modules`.
"""

from __future__ import annotations

from typing import Optional, List, Tuple
import importlib
import importlib.util
import os
import sys
from pathlib import Path
import shlex
from types import ModuleType


def _ensure_repo_root_on_sys_path(pkg_file: Optional[Path] = None) -> Optional[Path]:
    """Ensure the repository root (where top-level modules live) is importable.

    The project currently keeps key modules like `CLI.py` at the repo root.
    When `mm` is invoked from a different working directory, that repo root is
    not necessarily on `sys.path`, which breaks `import CLI`.

    We infer the repo root by walking up from this package location and looking
    for a sibling `CLI.py` or checking parent directories.

    `pkg_file` exists for unit tests; production uses this module's `__file__`.
    """
    try:
        pkg_dir = (pkg_file or Path(__file__)).resolve().parent
    except Exception:
        return

    # Strategy 1: Look for CLI.py in parent directories (starting from scripts parent)
    for parent in pkg_dir.parents:
        try:
            if (parent / "CLI.py").exists():
                parent_str = str(parent)
                if parent_str not in sys.path:
                    sys.path.insert(0, parent_str)
                return parent
        except Exception:
            continue
    
    # Strategy 2: If in a venv, check the .venv/.. path (project root)
    try:
        # If this file is in .../venv/lib/python3.x/site-packages/scripts/
        # then we want to go up to find the project root
        current = pkg_dir.resolve()
        for _ in range(20):  # Safety limit
            current = current.parent
            if (current / "CLI.py").exists():
                parent_str = str(current)
                if parent_str not in sys.path:
                    sys.path.insert(0, parent_str)
                return current
    except Exception:
        pass
    
    return None


def _parse_mode_and_strip_args(args: List[str]) -> Tuple[Optional[str], List[str]]:
    """Parse --gui/--cli/--mode flags and return (mode, cleaned_args).

    The function removes any mode flags from the argument list so the selected
    runner can receive the remaining arguments untouched.

    Supported forms:
      --gui, -g, --gui=true
      --cli, -c, --cli=true
      --mode=gui|cli
      --mode gui|cli

    Raises ValueError on conflicting or invalid flags.
    """
    mode: Optional[str] = None
    out: List[str] = []
    i = 0
    while i < len(args):
        a = args[i]
        la = a.lower()

        # --gui / -g
        if la in ("--gui", "-g"):
            if mode and mode != "gui":
                raise ValueError("Conflicting mode flags: found both 'gui' and 'cli'")
            mode = "gui"
            i += 1
            continue
        if la.startswith("--gui="):
            val = la.split("=", 1)[1]
            if val and val not in ("0", "false", "no", "off"):
                if mode and mode != "gui":
                    raise ValueError(
                        "Conflicting mode flags: found both 'gui' and 'cli'"
                    )
                mode = "gui"
            i += 1
            continue

        # --cli / -c
        if la in ("--cli", "-c"):
            if mode and mode != "cli":
                raise ValueError("Conflicting mode flags: found both 'gui' and 'cli'")
            mode = "cli"
            i += 1
            continue
        if la.startswith("--cli="):
            val = la.split("=", 1)[1]
            if val and val not in ("0", "false", "no", "off"):
                if mode and mode != "cli":
                    raise ValueError(
                        "Conflicting mode flags: found both 'gui' and 'cli'"
                    )
                mode = "cli"
            i += 1
            continue

        # --mode
        if la.startswith("--mode="):
            val = la.split("=", 1)[1]
            val = val.lower()
            if val not in ("gui", "cli"):
                raise ValueError("--mode must be 'gui' or 'cli'")
            if mode and mode != val:
                raise ValueError("Conflicting mode flags: found both 'gui' and 'cli'")
            mode = val
            i += 1
            continue
        if la == "--mode":
            if i + 1 >= len(args):
                raise ValueError("--mode requires a value ('gui' or 'cli')")
            val = args[i + 1].lower()
            if val not in ("gui", "cli"):
                raise ValueError("--mode must be 'gui' or 'cli'")
            if mode and mode != val:
                raise ValueError("Conflicting mode flags: found both 'gui' and 'cli'")
            mode = val
            i += 2
            continue

        # Not a mode flag; keep it
        out.append(a)
        i += 1

    return mode, out


def _run_cli(clean_args: List[str]) -> int:
    """Run the CLI runner (MedeiaCLI) with cleaned argv list.

    The function supports three modes (in order):
      1) If a `medeia_entry` module is present in sys.modules (for tests/legacy
         scenarios), use it as the source of `MedeiaCLI`.
      2) If running from a development checkout, import the top-level `CLI` and
         use `MedeiaCLI` from there.
      3) Otherwise fail with a helpful message suggesting an editable install.
    """
    try:
        sys.argv[1:] = list(clean_args)
    except Exception:
        pass

    # 1) Check for an in-memory 'medeia_entry' module (tests/legacy installs)
    MedeiaCLI = None
    if "medeia_entry" in sys.modules:
        mod = sys.modules.get("medeia_entry")
        if hasattr(mod, "MedeiaCLI"):
            MedeiaCLI = getattr(mod, "MedeiaCLI")
        else:
            # Preserve the existing error message used by tests that inject a
            # dummy 'medeia_entry' without a `MedeiaCLI` attribute.
            raise ImportError(
                "Imported module 'medeia_entry' does not define 'MedeiaCLI' and direct import of top-level 'CLI' failed.\n"
                "Remedy: ensure the top-level 'medeia_entry' module exports 'MedeiaCLI' or run from the project root/debug the checkout."
            )

    # 2) If no in-memory module provided the class, try importing the repo-root CLI
    if MedeiaCLI is None:
        try:
            repo_root = _ensure_repo_root_on_sys_path()
            from CLI import MedeiaCLI as _M  # type: ignore
            MedeiaCLI = _M
        except Exception as exc:
            # Provide diagnostic information
            import traceback
            error_msg = (
                "Could not import 'MedeiaCLI'. This often means the project is not available on sys.path.\n"
                "Diagnostic info:\n"
                f"  - sys.executable: {sys.executable}\n"
                f"  - sys.path (first 5): {sys.path[:5]}\n"
                f"  - current working directory: {Path.cwd()}\n"
                f"  - this file: {Path(__file__).resolve()}\n"
            )
            try:
                repo = _ensure_repo_root_on_sys_path()
                if repo:
                    error_msg += f"  - detected repo root: {repo}\n"
                    cli_path = repo / "CLI.py"
                    error_msg += f"  - CLI.py exists at {cli_path}: {cli_path.exists()}\n"
            except:
                pass
            error_msg += (
                "\nRemedy: Run 'pip install -e scripts' from the project root or re-run the bootstrap script.\n"
                "Set MM_DEBUG=1 to enable detailed diagnostics."
            )
            if os.environ.get("MM_DEBUG"):
                error_msg += f"\n\nTraceback:\n{traceback.format_exc()}"
            raise ImportError(error_msg) from exc

    try:
        app = MedeiaCLI()
        app.run()
        return 0
    except SystemExit as exc:
        return int(getattr(exc, "code", 0) or 0)


def _run_gui(clean_args: List[str]) -> int:
    """Run the TUI runner (PipelineHubApp).

    The TUI is imported lazily; if Textual or the TUI code is unavailable we
    give a helpful error message and exit non‑zero.
    """
    try:
        repo_root = _ensure_repo_root_on_sys_path()
        tui_mod: Optional[ModuleType] = None
        selected_module: Optional[str] = None
        last_exc: Optional[Exception] = None

        def _load_from_file(path: Path) -> ModuleType:
            spec = importlib.util.spec_from_file_location(
                "medeia_tui_entry",
                path,
                submodule_search_locations=[str(path.parent)],
            )
            if spec is None or spec.loader is None:
                raise ModuleNotFoundError(f"Cannot load TUI from {path}")
            module = importlib.util.module_from_spec(spec)
            sys.modules[spec.name] = module
            spec.loader.exec_module(module)  # type: ignore[attr-defined]
            return module

        if repo_root is not None:
            tui_file = repo_root / "TUI.py"
            if tui_file.exists():
                try:
                    tui_mod = _load_from_file(tui_file)
                    selected_module = str(tui_file)
                except Exception as exc:
                    last_exc = exc
        if tui_mod is None:
            for candidate in ("TUI.tui", "TUI"):
                try:
                    tui_mod = importlib.import_module(candidate)
                    selected_module = candidate
                    break
                except ModuleNotFoundError as exc:
                    last_exc = exc
        if tui_mod is None:
            raise last_exc or ModuleNotFoundError("No TUI module could be imported")
    except Exception as exc:
        print(
            "Error: Unable to import TUI (Textual may not be installed):",
            exc,
            file=sys.stderr,
        )
        return 2

    try:
        PipelineHubApp = getattr(tui_mod, "PipelineHubApp")
    except AttributeError:
        module_hint = selected_module or "TUI"
        print(
            f"Error: '{module_hint}' does not expose 'PipelineHubApp'",
            file=sys.stderr,
        )
        return 2

    try:
        app = PipelineHubApp()
        app.run()
        return 0
    except SystemExit as exc:
        return int(getattr(exc, "code", 0) or 0)


def main(argv: Optional[List[str]] = None) -> int:
    """Entry point for console_scripts.

    Accepts an optional argv list (useful for testing). Mode flags are parsed
    and removed before dispatching to the selected runner.
    """
    args = list(argv) if argv is not None else list(sys.argv[1:])

    try:
        mode, clean_args = _parse_mode_and_strip_args(args)
    except ValueError as exc:
        print(f"Error parsing mode flags: {exc}", file=sys.stderr)
        return 2

    # Early environment sanity check to detect urllib3/urllib3-future conflicts.
    # When a broken urllib3 is detected we print an actionable message and
    # exit early to avoid confusing import-time errors later during startup.
    try:
        from SYS.env_check import ensure_urllib3_ok

        try:
            ensure_urllib3_ok(exit_on_error=True)
        except SystemExit as exc:
            # Bubble out the exit code as the CLI return value for clearer
            # behavior in shell sessions and scripts.
            return int(getattr(exc, "code", 2) or 2)
    except Exception:
        # If the sanity check itself cannot be imported or run, don't block
        # startup; we'll continue and let normal import errors surface.
        pass

    # If GUI requested, delegate directly (GUI may decide to honor any args itself)
    if mode == "gui":
        return _run_gui(clean_args)

    # Support quoting a pipeline (or even a single full command) on the command line.
    #
    # - If the user provides a single argument that contains a pipe character,
    #   treat it as a pipeline and rewrite the args to call the internal `pipeline`
    #   subcommand so existing CLI pipeline handling is used.
    #
    # - If the user provides a single argument that contains whitespace but no pipe,
    #   expand it into argv tokens (PowerShell commonly encourages quoting strings).
    #
    # Examples:
        #    mm "download-file <url> | add-tag 'x' | add-file -store local"
        #    mm "download-file '<url>' -query 'format:720p' -path 'C:\\out'"
    if len(clean_args) == 1:
        single = clean_args[0]
        if "|" in single and not single.startswith("-"):
            clean_args = ["pipeline", "--pipeline", single]
        elif (not single.startswith("-")) and any(ch.isspace() for ch in single):
            try:
                expanded = shlex.split(single, posix=True)
                if expanded:
                    clean_args = list(expanded)
            except Exception:
                pass

    # Default to CLI if --cli is requested or no explicit mode provided.
    return _run_cli(clean_args)


if __name__ == "__main__":
    raise SystemExit(main())