import React, { useState } from "react";
import ReactMarkdown from "react-markdown";
import remarkGfm from "remark-gfm";
import remarkBreaks from "remark-breaks";
import rehypeRaw from "rehype-raw";
import rehypeSanitize, { defaultSchema } from "rehype-sanitize";
import { Prism as SyntaxHighlighter } from "react-syntax-highlighter";
import { Copy, Check } from "lucide-react";
import { useTheme } from "../context/ThemeContext";
import NewsletterSignup from "./NewsletterSignup";
import ContactForm from "./ContactForm";
import siteConfig from "../config/siteConfig";

// Sanitize schema that allows collapsible sections (details/summary)
const sanitizeSchema = {
  ...defaultSchema,
  tagNames: [...(defaultSchema.tagNames || []), "details", "summary"],
  attributes: {
    ...defaultSchema.attributes,
    details: ["open"], // Allow the 'open' attribute for expanded by default
  },
};

// Copy button component for code blocks
function CodeCopyButton({ code }: { code: string }) {
  const [copied, setCopied] = useState(false);

  const handleCopy = async () => {
    await navigator.clipboard.writeText(code);
    setCopied(true);
    setTimeout(() => setCopied(false), 2000);
  };

  return (
    <button
      className="code-copy-button"
      onClick={handleCopy}
      aria-label={copied ? "Copied!" : "Copy code"}
      title={copied ? "Copied!" : "Copy code"}
    >
      {copied ? <Check size={14} /> : <Copy size={14} />}
    </button>
  );
}

// Cursor Dark Theme colors for syntax highlighting
const cursorDarkTheme: { [key: string]: React.CSSProperties } = {
  'code[class*="language-"]': {
    color: "#d4d4d4",
    background: "#1e1e1e",
    fontFamily:
      "SF Mono, Monaco, Cascadia Code, Roboto Mono, Consolas, Courier New, monospace",
    fontSize: "14px",
    textAlign: "left" as const,
    whiteSpace: "pre" as const,
    wordSpacing: "normal",
    wordBreak: "normal" as const,
    wordWrap: "normal" as const,
    lineHeight: "1.6",
    tabSize: 4,
    hyphens: "none" as const,
  },
  'pre[class*="language-"]': {
    color: "#d4d4d4",
    background: "#1e1e1e",
    fontFamily:
      "SF Mono, Monaco, Cascadia Code, Roboto Mono, Consolas, Courier New, monospace",
    fontSize: "14px",
    textAlign: "left" as const,
    whiteSpace: "pre" as const,
    wordSpacing: "normal",
    wordBreak: "normal" as const,
    wordWrap: "normal" as const,
    lineHeight: "1.6",
    tabSize: 4,
    hyphens: "none" as const,
    padding: "1.5em",
    margin: "1.5em 0",
    overflow: "auto" as const,
    borderRadius: "8px",
  },
  comment: { color: "#6a9955", fontStyle: "italic" },
  prolog: { color: "#6a9955" },
  doctype: { color: "#6a9955" },
  cdata: { color: "#6a9955" },
  punctuation: { color: "#d4d4d4" },
  property: { color: "#9cdcfe" },
  tag: { color: "#569cd6" },
  boolean: { color: "#569cd6" },
  number: { color: "#b5cea8" },
  constant: { color: "#4fc1ff" },
  symbol: { color: "#4fc1ff" },
  deleted: { color: "#f44747" },
  selector: { color: "#d7ba7d" },
  "attr-name": { color: "#92c5f6" },
  string: { color: "#ce9178" },
  char: { color: "#ce9178" },
  builtin: { color: "#569cd6" },
  inserted: { color: "#6a9955" },
  operator: { color: "#d4d4d4" },
  entity: { color: "#dcdcaa" },
  url: { color: "#9cdcfe", textDecoration: "underline" },
  variable: { color: "#9cdcfe" },
  atrule: { color: "#569cd6" },
  "attr-value": { color: "#ce9178" },
  function: { color: "#dcdcaa" },
  "function-variable": { color: "#dcdcaa" },
  keyword: { color: "#569cd6" },
  regex: { color: "#d16969" },
  important: { color: "#569cd6", fontWeight: "bold" },
  bold: { fontWeight: "bold" },
  italic: { fontStyle: "italic" },
  namespace: { opacity: 0.7 },
  "class-name": { color: "#4ec9b0" },
  parameter: { color: "#9cdcfe" },
  decorator: { color: "#dcdcaa" },
};

// Cursor Light Theme colors for syntax highlighting
const cursorLightTheme: { [key: string]: React.CSSProperties } = {
  'code[class*="language-"]': {
    color: "#171717",
    background: "#f5f5f5",
    fontFamily:
      "SF Mono, Monaco, Cascadia Code, Roboto Mono, Consolas, Courier New, monospace",
    fontSize: "14px",
    textAlign: "left" as const,
    whiteSpace: "pre" as const,
    wordSpacing: "normal",
    wordBreak: "normal" as const,
    wordWrap: "normal" as const,
    lineHeight: "1.6",
    tabSize: 4,
    hyphens: "none" as const,
  },
  'pre[class*="language-"]': {
    color: "#171717",
    background: "#f5f5f5",
    fontFamily:
      "SF Mono, Monaco, Cascadia Code, Roboto Mono, Consolas, Courier New, monospace",
    fontSize: "14px",
    textAlign: "left" as const,
    whiteSpace: "pre" as const,
    wordSpacing: "normal",
    wordBreak: "normal" as const,
    wordWrap: "normal" as const,
    lineHeight: "1.6",
    tabSize: 4,
    hyphens: "none" as const,
    padding: "1.5em",
    margin: "1.5em 0",
    overflow: "auto" as const,
    borderRadius: "8px",
  },
  comment: { color: "#6a737d", fontStyle: "italic" },
  prolog: { color: "#6a737d" },
  doctype: { color: "#6a737d" },
  cdata: { color: "#6a737d" },
  punctuation: { color: "#24292e" },
  property: { color: "#005cc5" },
  tag: { color: "#22863a" },
  boolean: { color: "#005cc5" },
  number: { color: "#005cc5" },
  constant: { color: "#005cc5" },
  symbol: { color: "#e36209" },
  deleted: { color: "#b31d28", background: "#ffeef0" },
  selector: { color: "#22863a" },
  "attr-name": { color: "#6f42c1" },
  string: { color: "#032f62" },
  char: { color: "#032f62" },
  builtin: { color: "#005cc5" },
  inserted: { color: "#22863a", background: "#f0fff4" },
  operator: { color: "#d73a49" },
  entity: { color: "#6f42c1" },
  url: { color: "#005cc5", textDecoration: "underline" },
  variable: { color: "#e36209" },
  atrule: { color: "#005cc5" },
  "attr-value": { color: "#032f62" },
  function: { color: "#6f42c1" },
  "function-variable": { color: "#6f42c1" },
  keyword: { color: "#d73a49" },
  regex: { color: "#032f62" },
  important: { color: "#d73a49", fontWeight: "bold" },
  bold: { fontWeight: "bold" },
  italic: { fontStyle: "italic" },
  namespace: { opacity: 0.7 },
  "class-name": { color: "#6f42c1" },
  parameter: { color: "#24292e" },
  decorator: { color: "#6f42c1" },
};

// Tan Theme colors for syntax highlighting
const cursorTanTheme: { [key: string]: React.CSSProperties } = {
  'code[class*="language-"]': {
    color: "#1a1a1a",
    background: "#f0ece4",
    fontFamily:
      "SF Mono, Monaco, Cascadia Code, Roboto Mono, Consolas, Courier New, monospace",
    fontSize: "14px",
    textAlign: "left" as const,
    whiteSpace: "pre" as const,
    wordSpacing: "normal",
    wordBreak: "normal" as const,
    wordWrap: "normal" as const,
    lineHeight: "1.6",
    tabSize: 4,
    hyphens: "none" as const,
  },
  'pre[class*="language-"]': {
    color: "#1a1a1a",
    background: "#f0ece4",
    fontFamily:
      "SF Mono, Monaco, Cascadia Code, Roboto Mono, Consolas, Courier New, monospace",
    fontSize: "14px",
    textAlign: "left" as const,
    whiteSpace: "pre" as const,
    wordSpacing: "normal",
    wordBreak: "normal" as const,
    wordWrap: "normal" as const,
    lineHeight: "1.6",
    tabSize: 4,
    hyphens: "none" as const,
    padding: "1.5em",
    margin: "1.5em 0",
    overflow: "auto" as const,
    borderRadius: "8px",
  },
  comment: { color: "#7a7a7a", fontStyle: "italic" },
  prolog: { color: "#7a7a7a" },
  doctype: { color: "#7a7a7a" },
  cdata: { color: "#7a7a7a" },
  punctuation: { color: "#1a1a1a" },
  property: { color: "#8b7355" },
  tag: { color: "#8b5a2b" },
  boolean: { color: "#8b5a2b" },
  number: { color: "#8b5a2b" },
  constant: { color: "#8b5a2b" },
  symbol: { color: "#a67c52" },
  deleted: { color: "#b31d28" },
  selector: { color: "#6b8e23" },
  "attr-name": { color: "#8b7355" },
  string: { color: "#6b8e23" },
  char: { color: "#6b8e23" },
  builtin: { color: "#8b5a2b" },
  inserted: { color: "#6b8e23" },
  operator: { color: "#a67c52" },
  entity: { color: "#8b7355" },
  url: { color: "#8b7355", textDecoration: "underline" },
  variable: { color: "#a67c52" },
  atrule: { color: "#8b5a2b" },
  "attr-value": { color: "#6b8e23" },
  function: { color: "#8b7355" },
  "function-variable": { color: "#8b7355" },
  keyword: { color: "#8b5a2b" },
  regex: { color: "#6b8e23" },
  important: { color: "#8b5a2b", fontWeight: "bold" },
  bold: { fontWeight: "bold" },
  italic: { fontStyle: "italic" },
  namespace: { opacity: 0.7 },
  "class-name": { color: "#8b7355" },
  parameter: { color: "#1a1a1a" },
  decorator: { color: "#8b7355" },
};

interface BlogPostProps {
  content: string;
  slug?: string; // For tracking source of newsletter/contact form signups
  pageType?: "post" | "page"; // Type of content (for tracking)
}

// Content segment types for inline embeds
type ContentSegment =
  | { type: "content"; value: string }
  | { type: "newsletter" }
  | { type: "contactform" };

// Parse content for inline embed placeholders
// Supports: <!-- newsletter --> and <!-- contactform -->
function parseContentForEmbeds(content: string): ContentSegment[] {
  const segments: ContentSegment[] = [];
  
  // Pattern matches <!-- newsletter --> or <!-- contactform --> (case insensitive)
  const pattern = /<!--\s*(newsletter|contactform)\s*-->/gi;
  
  let lastIndex = 0;
  let match: RegExpExecArray | null;
  
  while ((match = pattern.exec(content)) !== null) {
    // Add content before the placeholder
    if (match.index > lastIndex) {
      const textBefore = content.slice(lastIndex, match.index);
      if (textBefore.trim()) {
        segments.push({ type: "content", value: textBefore });
      }
    }
    
    // Add the embed placeholder
    const embedType = match[1].toLowerCase();
    if (embedType === "newsletter") {
      segments.push({ type: "newsletter" });
    } else if (embedType === "contactform") {
      segments.push({ type: "contactform" });
    }
    
    lastIndex = match.index + match[0].length;
  }
  
  // Add remaining content after last placeholder
  if (lastIndex < content.length) {
    const remaining = content.slice(lastIndex);
    if (remaining.trim()) {
      segments.push({ type: "content", value: remaining });
    }
  }
  
  // If no placeholders found, return single content segment
  if (segments.length === 0) {
    segments.push({ type: "content", value: content });
  }
  
  return segments;
}

// Generate slug from heading text for anchor links
function generateSlug(text: string): string {
  return text
    .toLowerCase()
    .replace(/[^a-z0-9\s-]/g, "")
    .replace(/\s+/g, "-")
    .replace(/-+/g, "-")
    .trim();
}

// Extract text content from React children
function getTextContent(children: React.ReactNode): string {
  if (typeof children === "string") return children;
  if (Array.isArray(children)) {
    return children.map(getTextContent).join("");
  }
  if (children && typeof children === "object" && "props" in children) {
    return getTextContent((children as React.ReactElement).props.children);
  }
  return "";
}

// Anchor link component for headings
function HeadingAnchor({ id }: { id: string }) {
  const handleClick = (e: React.MouseEvent<HTMLAnchorElement>) => {
    // Copy URL to clipboard, but allow default scroll behavior
    const url = `${window.location.origin}${window.location.pathname}#${id}`;
    navigator.clipboard.writeText(url).catch(() => {
      // Silently fail if clipboard API is not available
    });
  };

  return (
    <a
      href={`#${id}`}
      className="heading-anchor"
      onClick={handleClick}
      aria-label="Copy link to heading"
      title="Copy link to heading"
    >
      #
    </a>
  );
}

export default function BlogPost({ content, slug, pageType = "post" }: BlogPostProps) {
  const { theme } = useTheme();

  const getCodeTheme = () => {
    switch (theme) {
      case "dark":
        return cursorDarkTheme;
      case "light":
        return cursorLightTheme;
      case "tan":
        return cursorTanTheme;
      default:
        return cursorDarkTheme;
    }
  };

  // Parse content for inline embeds
  const segments = parseContentForEmbeds(content);
  const hasInlineEmbeds = segments.some((s) => s.type !== "content");

  // Helper to render a single markdown segment
  const renderMarkdown = (markdownContent: string, key?: number) => (
    <ReactMarkdown
      key={key}
      remarkPlugins={[remarkGfm, remarkBreaks]}
      rehypePlugins={[rehypeRaw, [rehypeSanitize, sanitizeSchema]]}
      components={{
        code(codeProps) {
          const { className, children, node, style, ...restProps } = codeProps as {
            className?: string;
            children?: React.ReactNode;
            node?: { tagName?: string; properties?: { className?: string[] } };
            style?: React.CSSProperties;
            inline?: boolean;
          };
          const match = /language-(\w+)/.exec(className || "");
          
          // Detect inline code: no language class AND content is short without newlines
          const codeContent = String(children);
          const hasNewlines = codeContent.includes('\n');
          const isShort = codeContent.length < 80;
          const hasLanguage = !!match || !!className;
          
          // It's inline only if: no language, short content, no newlines
          const isInline = !hasLanguage && isShort && !hasNewlines;

          if (isInline) {
            return (
              <code className="inline-code" style={style} {...restProps}>
                {children}
              </code>
            );
          }

          const codeString = String(children).replace(/\n$/, "");
          const language = match ? match[1] : "text";
          const isTextBlock = language === "text";
          
          // Custom styles for text blocks to enable wrapping
          const textBlockStyle = isTextBlock ? {
            whiteSpace: "pre-wrap" as const,
            wordWrap: "break-word" as const,
            overflowWrap: "break-word" as const,
          } : {};
          
          return (
            <div className={`code-block-wrapper ${isTextBlock ? "code-block-text" : ""}`}>
              {match && <span className="code-language">{match[1]}</span>}
              <CodeCopyButton code={codeString} />
              <SyntaxHighlighter
                style={getCodeTheme()}
                language={language}
                PreTag="div"
                customStyle={textBlockStyle}
                codeTagProps={isTextBlock ? { style: textBlockStyle } : undefined}
              >
                {codeString}
              </SyntaxHighlighter>
            </div>
          );
        },
        img({ src, alt }) {
          return (
            <span className="blog-image-wrapper">
              <img
                src={src}
                alt={alt || ""}
                className="blog-image"
                loading="lazy"
              />
              {alt && <span className="blog-image-caption">{alt}</span>}
            </span>
          );
        },
        a({ href, children }) {
          const isExternal = href?.startsWith("http");
          return (
            <a
              href={href}
              target={isExternal ? "_blank" : undefined}
              rel={isExternal ? "noopener noreferrer" : undefined}
              className="blog-link"
            >
              {children}
            </a>
          );
        },
        blockquote({ children }) {
          return (
            <blockquote className="blog-blockquote">{children}</blockquote>
          );
        },
        h1({ children }) {
          const id = generateSlug(getTextContent(children));
          return (
            <h1 id={id} className="blog-h1">
              <HeadingAnchor id={id} />
              {children}
            </h1>
          );
        },
        h2({ children }) {
          const id = generateSlug(getTextContent(children));
          return (
            <h2 id={id} className="blog-h2">
              <HeadingAnchor id={id} />
              {children}
            </h2>
          );
        },
        h3({ children }) {
          const id = generateSlug(getTextContent(children));
          return (
            <h3 id={id} className="blog-h3">
              <HeadingAnchor id={id} />
              {children}
            </h3>
          );
        },
        h4({ children }) {
          const id = generateSlug(getTextContent(children));
          return (
            <h4 id={id} className="blog-h4">
              <HeadingAnchor id={id} />
              {children}
            </h4>
          );
        },
        h5({ children }) {
          const id = generateSlug(getTextContent(children));
          return (
            <h5 id={id} className="blog-h5">
              <HeadingAnchor id={id} />
              {children}
            </h5>
          );
        },
        h6({ children }) {
          const id = generateSlug(getTextContent(children));
          return (
            <h6 id={id} className="blog-h6">
              <HeadingAnchor id={id} />
              {children}
            </h6>
          );
        },
        ul({ children }) {
          return <ul className="blog-ul">{children}</ul>;
        },
        ol({ children }) {
          return <ol className="blog-ol">{children}</ol>;
        },
        li({ children }) {
          return <li className="blog-li">{children}</li>;
        },
        hr() {
          return <hr className="blog-hr" />;
        },
        // Table components for GitHub-style tables
        table({ children }) {
          return (
            <div className="blog-table-wrapper">
              <table className="blog-table">{children}</table>
            </div>
          );
        },
        thead({ children }) {
          return <thead className="blog-thead">{children}</thead>;
        },
        tbody({ children }) {
          return <tbody className="blog-tbody">{children}</tbody>;
        },
        tr({ children }) {
          return <tr className="blog-tr">{children}</tr>;
        },
        th({ children }) {
          return <th className="blog-th">{children}</th>;
        },
        td({ children }) {
          return <td className="blog-td">{children}</td>;
        },
      }}
    >
      {markdownContent}
    </ReactMarkdown>
  );

  // Build source string for tracking
  const sourcePrefix = pageType === "page" ? "page" : "post";
  const source = slug ? `${sourcePrefix}:${slug}` : sourcePrefix;

  // Render with inline embeds if placeholders exist
  if (hasInlineEmbeds) {
    return (
      <article className="blog-post-content">
        {segments.map((segment, index) => {
          if (segment.type === "newsletter") {
            // Newsletter signup inline
            return siteConfig.newsletter?.enabled ? (
              <NewsletterSignup
                key={`newsletter-${index}`}
                source={pageType === "page" ? "post" : "post"}
                postSlug={slug}
              />
            ) : null;
          }
          if (segment.type === "contactform") {
            // Contact form inline
            return siteConfig.contactForm?.enabled ? (
              <ContactForm
                key={`contactform-${index}`}
                source={source}
              />
            ) : null;
          }
          // Markdown content segment
          return renderMarkdown(segment.value, index);
        })}
      </article>
    );
  }

  // No inline embeds, render content normally
  return (
    <article className="blog-post-content">
      <ReactMarkdown
        remarkPlugins={[remarkGfm, remarkBreaks]}
        rehypePlugins={[rehypeRaw, [rehypeSanitize, sanitizeSchema]]}
        components={{
          code(codeProps) {
            const { className, children, node, style, ...restProps } = codeProps as {
              className?: string;
              children?: React.ReactNode;
              node?: { tagName?: string; properties?: { className?: string[] } };
              style?: React.CSSProperties;
              inline?: boolean;
            };
            const match = /language-(\w+)/.exec(className || "");
            
            // Detect inline code: no language class AND content is short without newlines
            // Fenced code blocks (even without language) are longer or have structure
            const codeContent = String(children);
            const hasNewlines = codeContent.includes('\n');
            const isShort = codeContent.length < 80;
            const hasLanguage = !!match || !!className;
            
            // It's inline only if: no language, short content, no newlines
            const isInline = !hasLanguage && isShort && !hasNewlines;

            if (isInline) {
              return (
                <code className="inline-code" style={style} {...restProps}>
                  {children}
                </code>
              );
            }

            const codeString = String(children).replace(/\n$/, "");
            const language = match ? match[1] : "text";
            const isTextBlock = language === "text";
            
            // Custom styles for text blocks to enable wrapping
            const textBlockStyle = isTextBlock ? {
              whiteSpace: "pre-wrap" as const,
              wordWrap: "break-word" as const,
              overflowWrap: "break-word" as const,
            } : {};
            
            return (
              <div className={`code-block-wrapper ${isTextBlock ? "code-block-text" : ""}`}>
                {match && <span className="code-language">{match[1]}</span>}
                <CodeCopyButton code={codeString} />
                <SyntaxHighlighter
                  style={getCodeTheme()}
                  language={language}
                  PreTag="div"
                  customStyle={textBlockStyle}
                  codeTagProps={isTextBlock ? { style: textBlockStyle } : undefined}
                >
                  {codeString}
                </SyntaxHighlighter>
              </div>
            );
          },
          img({ src, alt }) {
            return (
              <span className="blog-image-wrapper">
                <img
                  src={src}
                  alt={alt || ""}
                  className="blog-image"
                  loading="lazy"
                />
                {alt && <span className="blog-image-caption">{alt}</span>}
              </span>
            );
          },
          a({ href, children }) {
            const isExternal = href?.startsWith("http");
            return (
              <a
                href={href}
                target={isExternal ? "_blank" : undefined}
                rel={isExternal ? "noopener noreferrer" : undefined}
                className="blog-link"
              >
                {children}
              </a>
            );
          },
          blockquote({ children }) {
            return (
              <blockquote className="blog-blockquote">{children}</blockquote>
            );
          },
          h1({ children }) {
            const id = generateSlug(getTextContent(children));
            return (
              <h1 id={id} className="blog-h1">
                <HeadingAnchor id={id} />
                {children}
              </h1>
            );
          },
          h2({ children }) {
            const id = generateSlug(getTextContent(children));
            return (
              <h2 id={id} className="blog-h2">
                <HeadingAnchor id={id} />
                {children}
              </h2>
            );
          },
          h3({ children }) {
            const id = generateSlug(getTextContent(children));
            return (
              <h3 id={id} className="blog-h3">
                <HeadingAnchor id={id} />
                {children}
              </h3>
            );
          },
          h4({ children }) {
            const id = generateSlug(getTextContent(children));
            return (
              <h4 id={id} className="blog-h4">
                <HeadingAnchor id={id} />
                {children}
              </h4>
            );
          },
          h5({ children }) {
            const id = generateSlug(getTextContent(children));
            return (
              <h5 id={id} className="blog-h5">
                <HeadingAnchor id={id} />
                {children}
              </h5>
            );
          },
          h6({ children }) {
            const id = generateSlug(getTextContent(children));
            return (
              <h6 id={id} className="blog-h6">
                <HeadingAnchor id={id} />
                {children}
              </h6>
            );
          },
          ul({ children }) {
            return <ul className="blog-ul">{children}</ul>;
          },
          ol({ children }) {
            return <ol className="blog-ol">{children}</ol>;
          },
          li({ children }) {
            return <li className="blog-li">{children}</li>;
          },
          hr() {
            return <hr className="blog-hr" />;
          },
          // Table components for GitHub-style tables
          table({ children }) {
            return (
              <div className="blog-table-wrapper">
                <table className="blog-table">{children}</table>
              </div>
            );
          },
          thead({ children }) {
            return <thead className="blog-thead">{children}</thead>;
          },
          tbody({ children }) {
            return <tbody className="blog-tbody">{children}</tbody>;
          },
          tr({ children }) {
            return <tr className="blog-tr">{children}</tr>;
          },
          th({ children }) {
            return <th className="blog-th">{children}</th>;
          },
          td({ children }) {
            return <td className="blog-td">{children}</td>;
          },
        }}
      >
        {content}
      </ReactMarkdown>
    </article>
  );
}