# -*- coding: utf-8 -*-
"""拖拽编程画布——图编译为 script_engine 可执行脚本（Python，script_type=0）。

编译策略：
- 变量声明统一提升到脚本头部（var_create），保证使用前已定义
- 函数定义（logic_function_def）生成 def + 函数体链
- 每个事件块作为独立入口分支
- 逻辑块生成控制流（for / while / if / else / 并行顺序展开）
- 动作块生成动作函数调用（move/rotate/scale/set_property/play_animation/
  play_sound/show_hide/camera/wait），由宿主运行时注册到 script_engine 白名单
- 产物仅含白名单兼容语法：赋值 / def / for / while / if-else / 函数调用 / 注释，
  无 import、无 class、无 lambda、无对象方法调用、无 async
- 表达式内 `@变量名` 引用统一替换为 Python 标识符（变量提升到头部后按名引用）
"""

import re

from .blocks import BLOCK_DEFS, get_dynamic_outputs
from .validator import validate_graph

_IDENT_RE = re.compile(r'^[A-Za-z_][A-Za-z0-9_]*$')
_SAFE_EXPR = re.compile(r"^[A-Za-z0-9_+\-*/%()<>=!&| .'\"]+$")
_VAR_REF = re.compile(r'@([A-Za-z_][A-Za-z0-9_]*)')


def _ident(name):
    s = re.sub(r'\W', '_', str(name or ''))
    if not s:
        return '_v'
    if s[0].isdigit():
        s = '_' + s
    return s


def _num(s):
    s = str(s or '').strip()
    try:
        float(s)
        return s
    except (TypeError, ValueError):
        return '0'


def _str(s):
    return "'%s'" % str(s or '').replace("'", "\\'")


def _expr(s):
    """表达式安全转义：表达式内 @var 引用 → 标识符；纯数字/安全表达式原样；其余当字符串。"""
    s = str(s or '').strip()
    s = _VAR_REF.sub(lambda m: _ident(m.group(1)), s)
    try:
        float(s)
        return s
    except (TypeError, ValueError):
        pass
    if (_SAFE_EXPR.match(s) and 'import' not in s and '__' not in s and ';' not in s
            and not s.startswith('lambda') and not s.startswith('class')):
        return s
    return _str(s)


def _val(s):
    """值转义：@var → 标识符；数字 → 原样；true/false → 布尔；其余 → 字符串字面量。"""
    s = str(s or '').strip()
    if s.startswith('@') and _IDENT_RE.match(s[1:]):
        return _ident(s[1:])
    try:
        f = float(s)
        return str(int(f)) if f == int(f) else s
    except (TypeError, ValueError):
        pass
    if s in ('true', 'True', '1'):
        return 'True'
    if s in ('false', 'False', '0'):
        return 'False'
    return _str(s)


def _block_label(btype):
    bdef = BLOCK_DEFS.get(btype) or {}
    return bdef.get("label", btype)


def _block_code(b):
    """生成单个块的执行代码行；返回 None 表示该块不生成独立代码（结构块/已提升）。"""
    btype = b.get("type")
    p = b.get("params") or {}
    if btype == "event_start":
        return "# 事件: 开始"
    if btype == "event_click":
        return "# 事件: 点击 %s (%s)" % (p.get("target", ''), p.get("button", 'left'))
    if btype == "event_hover":
        return "# 事件: 悬停 %s %s" % (p.get("target", ''), p.get("state", 'enter'))
    if btype == "event_timer":
        return "# 事件: 定时 每 %s 秒 × %s 次" % (p.get("interval", ''), p.get("repeat", '-1'))
    if btype == "event_collision":
        return "# 事件: 碰撞 %s × %s" % (p.get("entity_a", ''), p.get("entity_b", ''))
    if btype == "event_keyboard":
        return "# 事件: 键盘 %s (%s)" % (p.get("key", ''), p.get("action", 'keydown'))
    if btype == "logic_sequence":
        return "# 顺序执行"
    if btype == "logic_wait":
        return "wait(seconds=%s)" % _num(p.get("seconds", '0'))
    if btype == "logic_function_call":
        return "%s()" % _ident(p.get("name", 'fn'))
    if btype == "var_create":
        return None  # 已提升到头部变量声明区
    if btype == "var_assign":
        return "%s = %s" % (_ident(p.get("name", '_v')), _val(p.get("value", '0')))
    if btype == "var_read":
        return "%s = %s" % (_ident(p.get("result", '_r')), _ident(p.get("name", '_v')))
    if btype == "expr_arith":
        return "%s = %s %s %s" % (_ident(p.get("result", '_r')), _expr(p.get("operand_a", '0')),
                                  p.get("operator", '+'), _expr(p.get("operand_b", '0')))
    if btype == "expr_compare":
        return "%s = %s %s %s" % (_ident(p.get("result", '_r')), _expr(p.get("operand_a", '0')),
                                  p.get("operator", '=='), _expr(p.get("operand_b", '0')))
    if btype == "expr_logic":
        op = p.get("operator", 'and')
        a, bv = _expr(p.get("operand_a", 'True')), _expr(p.get("operand_b", 'True'))
        body = "not %s" % a if op == 'not' else "%s %s %s" % (a, op, bv)
        return "%s = %s" % (_ident(p.get("result", '_r')), body)
    # 动作
    if btype == "action_move":
        return "move(entity=%s, x=%s, y=%s, duration=%s)" % (
            _str(p.get("entity", '')), _num(p.get("x", '0')), _num(p.get("y", '0')), _num(p.get("duration", '0')))
    if btype == "action_rotate":
        return "rotate(entity=%s, angle=%s, duration=%s)" % (
            _str(p.get("entity", '')), _num(p.get("angle", '0')), _num(p.get("duration", '0')))
    if btype == "action_scale":
        return "scale(entity=%s, scale_x=%s, scale_y=%s, duration=%s)" % (
            _str(p.get("entity", '')), _num(p.get("scale_x", '1')), _num(p.get("scale_y", '1')),
            _num(p.get("duration", '0')))
    if btype == "action_set_property":
        return "set_property(entity=%s, property=%s, value=%s)" % (
            _str(p.get("entity", '')), _str(p.get("property", '')), _str(p.get("value", '')))
    if btype == "action_play_animation":
        return "play_animation(entity=%s, animation=%s)" % (
            _str(p.get("entity", '')), _str(p.get("animation", '')))
    if btype == "action_play_sound":
        return "play_sound(entity=%s, sound=%s)" % (_str(p.get("entity", '')), _str(p.get("sound", '')))
    if btype == "action_show_hide":
        return "show_hide(entity=%s, visible=%s)" % (_str(p.get("entity", '')), _val(p.get("visible", 'true')))
    if btype == "action_camera":
        return "camera(camera_id=%s, mode=%s, x=%s, y=%s, zoom=%s)" % (
            _str(p.get("camera_id", 'main')), _str(p.get("mode", 'follow')),
            _num(p.get("x", '0')), _num(p.get("y", '0')), _num(p.get("zoom", '1')))
    return None


def _emit_chain(bid, bmap, adj, indent, visited=None):
    """沿输出端口生成执行代码（每块仅访问一次防环）。返回代码行列表。"""
    if visited is None:
        visited = set()
    if bid in visited or bid not in bmap:
        return []
    visited.add(bid)
    b = bmap[bid]
    btype = b.get("type")
    p = b.get("params") or {}
    ind = '    ' * indent
    lines = []
    outs = adj.get(bid, [])

    if btype == "logic_condition":
        lines.append(ind + "if %s:" % _expr(p.get("condition", 'True')))
        t = [c for c in outs if c.get("fromPort") == 'true']
        if t:
            lines.extend(_emit_chain(t[0].get("to"), bmap, adj, indent + 1, visited))
        else:
            lines.append(ind + "    pass")
        lines.append(ind + "else:")
        f = [c for c in outs if c.get("fromPort") == 'false']
        if f:
            lines.extend(_emit_chain(f[0].get("to"), bmap, adj, indent + 1, visited))
        else:
            lines.append(ind + "    pass")
        return lines

    if btype == "logic_loop":
        mode = p.get("mode", 'count')
        if mode == 'while':
            lines.append(ind + "while %s:" % _expr(p.get("condition", 'True')))
        else:
            lines.append(ind + "for _i in range(%s):" % _num(p.get("times", '3')))
        nxt = [c for c in outs if c.get("fromPort") == 'out']
        if nxt:
            lines.extend(_emit_chain(nxt[0].get("to"), bmap, adj, indent + 1, visited))
        else:
            lines.append(ind + "    pass")
        return lines

    if btype in ("logic_branch", "logic_parallel"):
        prefix = 'branch' if btype == "logic_branch" else 'p'
        names = get_dynamic_outputs(btype, p) or []
        for i, port in enumerate(names, 1):
            lines.append(ind + "# %s分支%d" % ("并行" if btype == "logic_parallel" else "", i))
            br = [c for c in outs if c.get("fromPort") == port]
            if br:
                lines.extend(_emit_chain(br[0].get("to"), bmap, adj, indent, visited))
            else:
                lines.append(ind + "pass")
        return lines

    # 普通块
    code = _block_code(b)
    if code is not None:
        lines.append(ind + code)
    # 单输出继续
    nxt = [c for c in outs if c.get("fromPort") == 'out']
    if nxt:
        lines.extend(_emit_chain(nxt[0].get("to"), bmap, adj, indent, visited))
    return lines


def compile_graph(graph, meta=None):
    """编译画布 → {success, content, warnings, entry_points} 或 {success:False, errors:[...]}"""
    v = validate_graph(graph)
    if v["errors"]:
        return {"success": False, "valid": False, "errors": v["errors"]}

    blocks = graph.get("blocks") or []
    conns = graph.get("connections") or []
    bmap = {b.get("id"): b for b in blocks if b.get("id")}
    adj = {}
    for c in conns:
        adj.setdefault(c.get("from"), []).append(c)

    events = [b for b in blocks if (BLOCK_DEFS.get(b.get("type")) or {}).get("category") == "event"]

    lines = []
    lines.append("# -*- coding: utf-8 -*-")
    lines.append("# 拖拽编程画布编译产物 (drag compiler v1)")
    if meta:
        lines.append("# 画布: %s (id=%s)" % (meta.get("name", ''), meta.get("id", '')))
    lines.append("# 入口事件: %s" % ", ".join(
        "%s[%s]" % (e.get("id"), _block_label(e.get("type"))) for e in events))
    lines.append("")

    # 变量声明区（提升）
    var_decls = []
    for b in blocks:
        if b.get("type") == "var_create":
            p = b.get("params") or {}
            var_decls.append("%s = %s" % (_ident(p.get("name", '_v')), _val(p.get("initial_value", '0'))))
    if var_decls:
        lines.append("# ===== 变量声明 =====")
        lines.extend(var_decls)
        lines.append("")

    # 函数定义区
    funcs = [b for b in blocks if b.get("type") == "logic_function_def"]
    if funcs:
        lines.append("# ===== 函数定义 =====")
        for fb in funcs:
            p = fb.get("params") or {}
            lines.append("def %s():" % _ident(p.get("name", 'fn')))
            body = _emit_chain(fb.get("id"), bmap, adj, 1, set())
            lines.extend(body or ["    pass"])
            lines.append("")

    # 入口执行区（每个事件块一个分支）
    if not events:
        lines.append("# (无入口事件)")
    for ev in events:
        lines.append("# ===== 入口: %s [%s] =====" % (ev.get("id"), _block_label(ev.get("type"))))
        body = _emit_chain(ev.get("id"), bmap, adj, 0, set())
        lines.extend(body or ["pass"])
        lines.append("")

    content = "\n".join(lines).rstrip() + "\n"
    return {"success": True, "valid": True, "content": content,
            "warnings": v["warnings"],
            "entry_points": [e.get("id") for e in events]}