from __future__ import annotations

import re
from typing import Mapping

from .models import ParsedConfig, Setting


def _to_ini_value(setting: Setting, new_value: object) -> str:
    if setting.value_type == "bool":
        return "true" if bool(new_value) else "false"
    return str(new_value)


def _lua_quote(value: str) -> str:
    # Minimal Lua string escaping for double-quoted strings.
    value = (
        value.replace("\\", "\\\\")
        .replace('"', '\\"')
        .replace("\r", "\\r")
        .replace("\n", "\\n")
        .replace("\t", "\\t")
    )
    return f'"{value}"'


def _to_lua_value(setting: Setting, new_value: object) -> str:
    if setting.value_type == "bool":
        return "true" if bool(new_value) else "false"
    if setting.value_type == "int":
        return str(int(new_value))
    if setting.value_type == "float":
        # Keep a plain, readable float representation.
        return str(float(new_value))
    return _lua_quote(str(new_value))


def write_server_ini(parsed: ParsedConfig, updates: Mapping[str, object]) -> str:
    if parsed.source != "ini":
        raise ValueError("write_server_ini expects ParsedConfig(source='ini')")

    lines = list(parsed.lines)
    key_re = re.compile(r"^([A-Za-z0-9_]+)=(.*)$")
    for setting in parsed.settings:
        if setting.path not in updates:
            continue
        new_value = _to_ini_value(setting, updates[setting.path])
        original = lines[setting.line_index]
        line_no_nl = original.rstrip("\r\n")
        newline = original[len(line_no_nl) :]
        m = key_re.match(line_no_nl)
        if not m:
            continue
        key = m.group(1)
        lines[setting.line_index] = f"{key}={new_value}{newline}"
    return "".join(lines)


def write_sandboxvars_lua(parsed: ParsedConfig, updates: Mapping[str, object]) -> str:
    if parsed.source != "lua":
        raise ValueError("write_sandboxvars_lua expects ParsedConfig(source='lua')")

    lines = list(parsed.lines)
    for setting in parsed.settings:
        if setting.path not in updates:
            continue
        new_value = _to_lua_value(setting, updates[setting.path])

        original = lines[setting.line_index]
        line_no_nl = original.rstrip("\r\n")
        newline = original[len(line_no_nl) :]

        # Replace between '=' and the final comma.
        eq_index = line_no_nl.find("=")
        comma_index = line_no_nl.rfind(",")
        if eq_index == -1 or comma_index == -1 or comma_index <= eq_index:
            continue

        prefix = line_no_nl[: eq_index + 1]
        # Preserve at least one space after '=' for readability.
        prefix = prefix.rstrip() + " "
        # Keep original indentation + key as-is.
        suffix = line_no_nl[comma_index:] + newline
        lines[setting.line_index] = f"{prefix}{new_value}{suffix}"

    return "".join(lines)