import os
import platform
import re
import subprocess
import sys
from collections.abc import Sequence
from enum import IntEnum
from pathlib import Path
from typing import override

from rattler import Platform

# Regex pattern to match ANSI escape sequences
ANSI_ESCAPE_PATTERN = re.compile(r"\x1b\[[0-9;]*m")

PIXI_VERSION = "0.67.2"


ALL_PLATFORMS = '["linux-64", "osx-64", "osx-arm64", "win-64", "linux-ppc64le", "linux-aarch64"]'

CURRENT_PLATFORM = str(Platform.current())

EMPTY_BOILERPLATE_PROJECT = f"""
[workspace]
name = "test"
channels = []
platforms = ["{CURRENT_PLATFORM}"]
"""

CONDA_FORGE_CHANNEL = "https://prefix.dev/conda-forge"


class ExitCode(IntEnum):
    SUCCESS = 0
    FAILURE = 1
    INCORRECT_USAGE = 2
    COMMAND_NOT_FOUND = 127


class Output:
    command: Sequence[Path | str]
    stdout: str
    stderr: str
    returncode: int

    def __init__(self, command: Sequence[Path | str], stdout: str, stderr: str, returncode: int):
        self.command = command
        self.stdout = stdout
        self.stderr = stderr
        self.returncode = returncode

    @override
    def __str__(self) -> str:
        return f"command: {self.command}"


def verify_cli_command(
    command: Sequence[Path | str],
    expected_exit_code: ExitCode = ExitCode.SUCCESS,
    stdout_contains: str | list[str] | None = None,
    stdout_excludes: str | list[str] | None = None,
    stderr_contains: str | list[str] | None = None,
    stderr_excludes: str | list[str] | None = None,
    env: dict[str, str] | None = None,
    cwd: str | Path | None = None,
    reset_env: bool = False,
    strip_ansi: bool = False,
) -> Output:
    if reset_env:
        base_env = {}
        # On Windows, preserve essential system variables so temp file creation
        # doesn't fall back to C:\WINDOWS\ (which requires admin privileges).
        if sys.platform == "win32":
            for var in ("TEMP", "TMP", "SYSTEMROOT", "SYSTEMDRIVE"):
                if var in os.environ:
                    base_env[var] = os.environ[var]
    else:
        base_env = dict(os.environ)
    complete_env = base_env if env is None else base_env | env
    # Set `PIXI_NO_WRAP` to avoid to have miette wrapping lines
    complete_env |= {"PIXI_NO_WRAP": "1"}

    process = subprocess.run(
        command,
        capture_output=True,
        env=complete_env,
        cwd=cwd,
    )
    # Decode stdout and stderr explicitly using UTF-8
    stdout = process.stdout.decode("utf-8", errors="replace")
    stderr = process.stderr.decode("utf-8", errors="replace")

    # Optionally strip ANSI escape sequences for matching
    stdout_for_matching = ANSI_ESCAPE_PATTERN.sub("", stdout) if strip_ansi else stdout
    stderr_for_matching = ANSI_ESCAPE_PATTERN.sub("", stderr) if strip_ansi else stderr

    returncode = process.returncode
    output = Output(command, stdout, stderr, returncode)
    print(f"command: {command}, stdout: {stdout}, stderr: {stderr}, code: {returncode}")
    assert returncode == expected_exit_code, (
        f"Return code was {returncode}, expected {expected_exit_code}, stderr: {stderr}"
    )

    if stdout_contains:
        if isinstance(stdout_contains, str):
            stdout_contains = [stdout_contains]
        for substring in stdout_contains:
            assert substring in stdout_for_matching, (
                f"'{substring}'\n not found in stdout:\n {stdout}"
            )

    if stdout_excludes:
        if isinstance(stdout_excludes, str):
            stdout_excludes = [stdout_excludes]
        for substring in stdout_excludes:
            assert substring not in stdout_for_matching, (
                f"'{substring}'\n unexpectedly found in stdout:\n {stdout}"
            )

    if stderr_contains:
        if isinstance(stderr_contains, str):
            stderr_contains = [stderr_contains]
        for substring in stderr_contains:
            assert substring in stderr_for_matching, (
                f"'{substring}'\n not found in stderr:\n {stderr}"
            )

    if stderr_excludes:
        if isinstance(stderr_excludes, str):
            stderr_excludes = [stderr_excludes]
        for substring in stderr_excludes:
            assert substring not in stderr_for_matching, (
                f"'{substring}'\n unexpectedly found in stderr:\n {stderr}"
            )

    return output


def bat_extension(exe_name: str) -> str:
    if platform.system() == "Windows":
        return exe_name + ".bat"
    else:
        return exe_name


def exec_extension(exe_name: str) -> str:
    if platform.system() == "Windows":
        return exe_name + ".exe"
    else:
        return exe_name


def is_binary(path: Path) -> bool:
    textchars = bytearray({7, 8, 9, 10, 12, 13, 27} | set(range(0x20, 0x100)) - {0x7F})
    with open(path, "rb") as f:
        return bool(f.read(2048).translate(None, bytes(textchars)))


def pixi_dir(project_root: Path) -> Path:
    return project_root.joinpath(".pixi")


def default_env_path(project_root: Path) -> Path:
    return pixi_dir(project_root).joinpath("envs", "default")


def repo_root() -> Path:
    return Path(__file__).parents[2]


def current_platform() -> str:
    return str(Platform.current())


def get_manifest(directory: Path) -> Path:
    pixi_toml = directory / "pixi.toml"
    pyproject_toml = directory / "pyproject.toml"

    if pixi_toml.exists():
        return pixi_toml
    elif pyproject_toml.exists():
        return pyproject_toml
    else:
        raise ValueError("Neither pixi.toml nor pyproject.toml found")


def run_and_get_env(pixi: Path, *args: str, env_var: str) -> tuple[str | None, Output]:
    if sys.platform.startswith("win"):
        cmd = [str(pixi), "exec", *args, "--", "cmd", "/c", f"echo %{env_var}%"]
    else:
        cmd = [str(pixi), "exec", *args, "--", "printenv", env_var]

    try:
        result = subprocess.run(
            cmd,
            capture_output=True,
            text=True,
            encoding="utf-8",
            errors="replace",
        )

        value = result.stdout.strip()

        output = Output(
            command=cmd,
            stdout=value,
            stderr=result.stderr.strip(),
            returncode=result.returncode,
        )

        return (value if value and value != f"%{env_var}%" else None, output)
    except Exception as e:
        print(f"Error running command: {e}")
        print(f"Command: {' '.join(cmd)}")
        raise


# Command discovery utilities for testing CLI flag support


def discover_pixi_commands() -> set[str]:
    """Discover all available pixi commands by walking the docs/reference/cli/pixi directory.

    Returns:
        set[str]: Set of command names in the format "pixi command subcommand ..."

    Examples:
        {"pixi add", "pixi workspace channel add", "pixi shell", ...}
    """
    docs_path = repo_root() / "docs" / "reference" / "cli" / "pixi"
    commands: set[str] = set()

    if not docs_path.exists():
        return commands

    # Walk through all markdown files in the docs directory
    for md_file in docs_path.rglob("*.md"):
        # Get relative path from the pixi docs directory
        relative_path = md_file.relative_to(docs_path)

        # Convert file path to command format
        # e.g., "workspace/channel/add.md" -> "pixi workspace channel add"
        command_parts = ["pixi"] + list(relative_path.parts[:-1]) + [relative_path.stem]
        command = " ".join(command_parts)
        commands.add(command)

    return commands


def check_command_supports_flags(command_parts: list[str], *flag_names: str) -> tuple[bool, ...]:
    """Check if a command supports specific flags by examining its documentation.

    Args:
        command_parts: List of command parts (e.g., ["workspace", "channel", "add"])
        *flag_names: Variable number of flag names to check for (e.g., "--frozen", "--no-install")

    Returns:
        tuple[bool, ...]: Tuple of booleans indicating support for each flag in order

    Examples:
        check_command_supports_flags(["add"], "--frozen", "--no-install")
        # Returns: (True, True) if both flags are supported

        check_command_supports_flags(["shell"], "--frozen", "--locked", "--no-install")
        # Returns: (False, True, True) if only --locked and --no-install are supported
    """
    # Build the documentation file path
    docs_path = repo_root() / "docs" / "reference" / "cli" / "pixi"
    doc_file = docs_path / Path(*command_parts).with_suffix(".md")

    if not doc_file.exists():
        return tuple(False for _ in flag_names)

    try:
        doc_content = doc_file.read_text()

        # Check each flag
        results: list[bool] = []
        for flag_name in flag_names:
            results.append(flag_name in doc_content)

        return tuple(results)

    except (OSError, IOError):
        return tuple(False for _ in flag_names)


def find_commands_supporting_flags(*flag_names: str) -> list[str]:
    """Find all pixi commands that support ALL of the specified flags.

    Args:
        *flag_names: Variable number of flag names that commands must support

    Returns:
        List[str]: List of command names that support all specified flags

    Examples:
        find_commands_supporting_flags("--frozen", "--no-install")
        # Returns: ["pixi add", "pixi remove", "pixi run", ...]

        find_commands_supporting_flags("--locked", "--no-install")
        # Returns: ["pixi shell"] (special case that uses --locked instead of --frozen)
    """
    all_commands = discover_pixi_commands()
    supported_commands: list[str] = []

    for command_str in all_commands:
        # Skip the "pixi" prefix to get command parts
        command_parts = (
            command_str.split()[1:] if command_str.startswith("pixi ") else command_str.split()
        )

        # Skip empty commands
        if not command_parts:
            continue

        # Check if the command supports all specified flags
        flag_support = check_command_supports_flags(command_parts, *flag_names)

        # Only include if ALL flags are supported
        if all(flag_support):
            supported_commands.append(command_str)

    return sorted(supported_commands)


def find_commands_supporting_frozen_and_no_install() -> set[str]:
    """Convenience function to find commands supporting both --frozen and --no-install flags.

    This also includes commands that use --locked instead of --frozen (like pixi shell).

    Returns:
        List[str]: List of command names supporting freeze/lock and no-install functionality
    """
    # Find commands that support --frozen and --no-install
    return set(find_commands_supporting_flags("--frozen", "--no-install"))
