from abc import ABC, abstractmethod
from collections.abc import Iterable
from pathlib import Path
from typing import Any, Literal

import aiofiles
from pydantic import BaseModel, Field

from zhenxun.services.log import logger

from .base import ContainerComponent, RenderableComponent

__all__ = [
    "CodeElement",
    "ComponentElement",
    "HeadingElement",
    "ImageElement",
    "ListElement",
    "ListItemElement",
    "MarkdownData",
    "MarkdownElement",
    "QuoteElement",
    "RawHtmlElement",
    "TableElement",
    "TextElement",
]


class MarkdownElement(BaseModel, ABC):
    @abstractmethod
    def to_markdown(self) -> str:
        """Serializes the element to its Markdown string representation."""
        pass


class TextElement(MarkdownElement):
    type: Literal["text"] = "text"
    text: str

    def to_markdown(self) -> str:
        return self.text


class HeadingElement(MarkdownElement):
    type: Literal["heading"] = "heading"
    text: str
    """标题文本"""
    level: int = Field(..., ge=1, le=6, description="标题级别 (1-6)")
    """标题级别 (1-6)"""

    def to_markdown(self) -> str:
        return f"{'#' * self.level} {self.text}"


class ImageElement(MarkdownElement):
    type: Literal["image"] = "image"
    src: str
    """图片来源 (URL或data URI)"""
    alt: str = "image"
    """图片的替代文本"""

    def to_markdown(self) -> str:
        return f"![{self.alt}]({self.src})"


class CodeElement(MarkdownElement):
    type: Literal["code"] = "code"
    code: str
    """代码字符串"""
    language: str = ""
    """代码语言，用于语法高亮"""

    def to_markdown(self) -> str:
        return f"```{self.language}\n{self.code}\n```"


class RawHtmlElement(MarkdownElement):
    type: Literal["raw_html"] = "raw_html"
    html: str
    """原始HTML字符串"""

    def to_markdown(self) -> str:
        return self.html


class TableElement(MarkdownElement):
    type: Literal["table"] = "table"
    headers: list[str]
    """表格的表头列表"""
    rows: list[list[str]]
    """表格的数据行列表"""
    alignments: list[Literal["left", "center", "right"]] | None = None
    """每列的对齐方式"""

    def to_markdown(self) -> str:
        header_row = "| " + " | ".join(self.headers) + " |"

        if self.alignments:
            align_map = {"left": ":---", "center": ":---:", "right": "---:"}
            separator_row = (
                "| "
                + " | ".join([align_map.get(a, "---") for a in self.alignments])
                + " |"
            )
        else:
            separator_row = "| " + " | ".join(["---"] * len(self.headers)) + " |"

        data_rows = "\n".join(
            "| " + " | ".join(map(str, row)) + " |" for row in self.rows
        )
        return f"{header_row}\n{separator_row}\n{data_rows}"


class ContainerElement(MarkdownElement):
    content: list[MarkdownElement] = Field(
        default_factory=list, description="容器内包含的Markdown元素列表"
    )
    """容器内包含的Markdown元素列表"""


class QuoteElement(ContainerElement):
    type: Literal["quote"] = "quote"

    def to_markdown(self) -> str:
        inner_md = "\n".join(part.to_markdown() for part in self.content)
        return "\n".join([f"> {line}" for line in inner_md.split("\n")])


class ListItemElement(ContainerElement):
    def to_markdown(self) -> str:
        return "\n".join(part.to_markdown() for part in self.content)


class ListElement(ContainerElement):
    type: Literal["list"] = "list"
    ordered: bool = False
    """是否为有序列表 (例如 1., 2.)"""

    def to_markdown(self) -> str:
        lines = []
        for i, item in enumerate(self.content):
            if isinstance(item, ListItemElement):
                prefix = f"{i + 1}." if self.ordered else "*"
                item_content = item.to_markdown()
                lines.append(f"{prefix} {item_content}")
        return "\n".join(lines)


class ComponentElement(MarkdownElement):
    """一个特殊的元素，用于在Markdown流中持有另一个可渲染组件。"""

    type: Literal["component"] = "component"
    component: RenderableComponent
    """嵌入在Markdown中的可渲染组件"""

    def to_markdown(self) -> str:
        return ""


class MarkdownData(ContainerComponent):
    """Markdown转图片的数据模型"""

    style_name: str | None = None
    """Markdown内容的样式名称"""
    elements: list[MarkdownElement] = Field(
        default_factory=list, description="构成Markdown文档的元素列表"
    )
    """构成Markdown文档的元素列表"""
    width: int = 800
    """最终渲染图片的宽度"""
    css_path: str | None = None
    """自定义CSS文件的绝对路径"""

    @property
    def template_name(self) -> str:
        return "components/core/markdown"

    def get_children(self) -> Iterable[RenderableComponent]:
        """让CSS/JS依赖收集器能够递归地找到所有嵌入的组件。"""

        def find_components_recursive(
            elements: list[MarkdownElement],
        ) -> Iterable[RenderableComponent]:
            for element in elements:
                if isinstance(element, ComponentElement):
                    yield element.component
                    if hasattr(element.component, "get_children"):
                        yield from element.component.get_children()
                elif isinstance(element, ContainerElement):
                    yield from find_components_recursive(element.content)

        yield from find_components_recursive(self.elements)

    async def get_extra_css(self, context: Any) -> str:
        css_parts = []
        if self.component_css:
            css_parts.append(self.component_css)

        if self.css_path:
            css_file = Path(self.css_path)
            if css_file.is_file():
                async with aiofiles.open(css_file, encoding="utf-8") as f:
                    css_parts.append(await f.read())
            else:
                logger.warning(f"Markdown自定义CSS文件不存在: {self.css_path}")
        else:
            style_name = self.style_name or "light"
            css_path = await context.theme_manager.resolve_markdown_style_path(
                style_name, context
            )
            if css_path and css_path.exists():
                async with aiofiles.open(css_path, encoding="utf-8") as f:
                    css_parts.append(await f.read())

        return "\n".join(css_parts)