# -*- coding: utf-8 -*-
"""
Logik-Ausdruck-Evaluator fuer Ternary-Ausdruecke.

Wertet Ausdruecke der Form (condition ? result_true : result_false) aus.
Unterstuetzt Vergleichsoperatoren, Typ-Pruefung, Else-If-Ketten (::),
und Boolean-Keywords.

Portiert von PrrintText_cpp/format.cpp (logic Namespace).
"""

from __future__ import annotations

import re
from typing import Any


# Boolean-Keywords
_TRUE_KEYWORDS = {"true", "on", "yes", "ok", "success", "1", "wahr", "ja", "an"}
_FALSE_KEYWORDS = {"false", "off", "no", "error", "failed", "0", "falsch", "nein", "aus"}

# Vergleichsoperatoren (laengste zuerst, damit >= vor > matcht)
_OPERATORS = ["===", "!==", ">=", "<=", "!=", "==", ">", "<"]


def _try_parse_number(s: str) -> float | None:
    """Versucht einen String als Zahl zu parsen."""
    s = s.strip()
    if not s:
        return None
    try:
        return float(s)
    except ValueError:
        # Lokalisierte Formate: 1.234,56 → 1234.56
        if "," in s:
            try:
                return float(s.replace(".", "").replace(",", "."))
            except ValueError:
                pass
        return None


def _try_parse_version(s: str) -> tuple[int, ...] | None:
    """Versucht einen String als Version (x.y.z.w) zu parsen."""
    s = s.strip()
    parts = s.split(".")
    if len(parts) < 2 or len(parts) > 4:
        return None
    try:
        nums = tuple(int(p) for p in parts)
        return nums
    except ValueError:
        return None


def _is_truthy(value: str) -> bool:
    """Prueft ob ein Wert als 'wahr' gilt."""
    v = value.strip().lower()
    if v in _TRUE_KEYWORDS:
        return True
    if v in _FALSE_KEYWORDS:
        return False
    num = _try_parse_number(v)
    if num is not None:
        return num > 0
    # Nicht-leerer String → True
    return bool(v)


def _compare(lhs: str, op: str, rhs: str) -> bool:
    """Vergleicht zwei Werte mit dem gegebenen Operator."""
    lhs = lhs.strip()
    rhs = rhs.strip()

    # Typ-Pruefung mit ===
    if op == "===":
        return _type_check(lhs, rhs)
    if op == "!==":
        return not _type_check(lhs, rhs)

    # Zahlen vergleichen
    lnum = _try_parse_number(lhs)
    rnum = _try_parse_number(rhs)
    if lnum is not None and rnum is not None:
        return _compare_numbers(lnum, op, rnum)

    # Versionen vergleichen
    lver = _try_parse_version(lhs)
    rver = _try_parse_version(rhs)
    if lver is not None and rver is not None:
        return _compare_versions(lver, op, rver)

    # Boolean-Keywords
    lb = lhs.lower() in _TRUE_KEYWORDS
    rb = rhs.lower() in _TRUE_KEYWORDS
    if lhs.lower() in (_TRUE_KEYWORDS | _FALSE_KEYWORDS) and \
       rhs.lower() in (_TRUE_KEYWORDS | _FALSE_KEYWORDS):
        return _compare_numbers(float(lb), op, float(rb))

    # String-Vergleich (case-insensitive)
    llow = lhs.lower()
    rlow = rhs.lower()
    if op == "==":
        return llow == rlow
    if op == "!=":
        return llow != rlow
    if op == "<":
        return llow < rlow
    if op == ">":
        return llow > rlow
    if op == "<=":
        return llow <= rlow
    if op == ">=":
        return llow >= rlow

    return False


def _compare_numbers(a: float, op: str, b: float) -> bool:
    if op == "==":
        return a == b
    if op == "!=":
        return a != b
    if op == "<":
        return a < b
    if op == ">":
        return a > b
    if op == "<=":
        return a <= b
    if op == ">=":
        return a >= b
    return False


def _compare_versions(a: tuple[int, ...], op: str, b: tuple[int, ...]) -> bool:
    # Auf gleiche Laenge auffuellen
    max_len = max(len(a), len(b))
    a_padded = a + (0,) * (max_len - len(a))
    b_padded = b + (0,) * (max_len - len(b))

    if op == "==":
        return a_padded == b_padded
    if op == "!=":
        return a_padded != b_padded
    if op == "<":
        return a_padded < b_padded
    if op == ">":
        return a_padded > b_padded
    if op == "<=":
        return a_padded <= b_padded
    if op == ">=":
        return a_padded >= b_padded
    return False


def _type_check(value: str, type_name: str) -> bool:
    """Typ-Pruefung: value === int/float/bool/byte."""
    t = type_name.lower().strip()
    v = value.strip()

    if t == "int":
        try:
            int(v)
            return "." not in v
        except ValueError:
            return False
    if t in ("float", "decimal", "number", "numeric"):
        return _try_parse_number(v) is not None
    if t in ("bool", "boolean"):
        return v.lower() in (_TRUE_KEYWORDS | _FALSE_KEYWORDS)
    if t == "byte":
        try:
            n = int(v)
            return 0 <= n <= 255
        except ValueError:
            return False
    if t in ("string", "str"):
        return True
    if t == "empty":
        return v == ""
    return False


def _find_at_depth_0(text: str, needle: str, start: int = 0) -> int:
    """Findet needle bei Klammer-Tiefe 0."""
    depth = 0
    i = start
    nlen = len(needle)
    while i < len(text):
        if text[i] == "(":
            depth += 1
        elif text[i] == ")":
            depth -= 1
        elif depth == 0 and text[i:i + nlen] == needle:
            return i
        i += 1
    return -1


def _split_branches(text: str) -> list[str]:
    """Teilt den Ausdruck an :: bei Tiefe 0."""
    branches: list[str] = []
    start = 0
    while True:
        pos = _find_at_depth_0(text, "::", start)
        if pos == -1:
            branches.append(text[start:])
            break
        branches.append(text[start:pos])
        start = pos + 2
    return branches


def _parse_condition(text: str) -> tuple[str, str, str] | None:
    """Parst 'lhs op rhs' aus einem Bedingungsstring."""
    text = text.strip()

    # Operator finden (laengste zuerst)
    for op in _OPERATORS:
        pos = text.find(op)
        if pos != -1:
            lhs = text[:pos].strip()
            rhs = text[pos + len(op):].strip()
            return lhs, op, rhs

    return None


def eval_logic(expr: str) -> str | None:
    """
    Wertet einen logischen Ternary-Ausdruck aus.

    Format: condition ? result_true : result_false
    Else-If: c1 ? r1 :: c2 ? r2 :: ... : default

    Args:
        expr: Der Ausdruck (ohne die aeusseren Klammern).

    Returns:
        Das Ergebnis als String oder None bei Parse-Fehler.
    """
    expr = expr.strip()
    if not expr:
        return None

    # Branches aufteilen (an :: bei Tiefe 0)
    branches = _split_branches(expr)

    for i, branch in enumerate(branches):
        branch = branch.strip()
        is_last = (i == len(branches) - 1)

        # ? finden bei Tiefe 0
        q_pos = _find_at_depth_0(branch, "?")
        if q_pos == -1:
            if is_last:
                # Letzter Branch ohne ? → Default-Wert
                return branch
            continue

        condition_str = branch[:q_pos].strip()
        rest = branch[q_pos + 1:]

        # Bei letztem Branch: true_result : false_result
        # Bei nicht-letztem Branch: nur true_result
        if is_last:
            colon_pos = _find_at_depth_0(rest, ":")
            if colon_pos == -1:
                true_result = rest.strip()
                false_result = ""
            else:
                true_result = rest[:colon_pos].strip()
                false_result = rest[colon_pos + 1:].strip()
        else:
            true_result = rest.strip()
            false_result = None  # Kein False-Zweig bei Nicht-letztem Branch

        # Bedingung auswerten
        cond_result = _eval_condition(condition_str)

        if cond_result:
            return true_result
        elif is_last and false_result is not None:
            return false_result

    return None


def _eval_condition(condition: str) -> bool:
    """Wertet eine einzelne Bedingung aus."""
    condition = condition.strip()

    # Versuche Operator zu finden
    parsed = _parse_condition(condition)
    if parsed:
        lhs, op, rhs = parsed
        return _compare(lhs, op, rhs)

    # Kein Operator → Truthiness-Pruefung
    return _is_truthy(condition)