import { Workspace, DocEntity, TodoEntity, Entity } from "./types";
import { OutputData } from "@editorjs/editorjs";

/**
 * Convert EditorJS OutputData to Markdown
 */
export function docToMarkdown(content: OutputData): string {
  return content.blocks
    .map((block) => {
      switch (block.type) {
        case "header":
          return `${"#".repeat((block.data as any).level)} ${(block.data as any).text}`;

        case "paragraph":
          return `${(block.data as any).text}\n`;

        case "list":
          if ((block.data as any).style === "ordered") {
            return ((block.data as any).items as Array<{ content: string }>)
              .map((item, i) => `${i + 1}. ${item.content}`)
              .join("\n");
          } else {
            return ((block.data as any).items as Array<{ content: string }>)
              .map((item) => `- ${item.content}`)
              .join("\n");
          }

        case "code":
          return `\`\`\`\n${(block.data as any).code}\n\`\`\``;

        case "quote":
          return `> ${(block.data as any).text}`;

        case "delimiter":
          return `---`;

        case "image":
          return `![${(block.data as any).caption || ""}](${(block.data as any).file.url})`;

        default:
          return "";
      }
    })
    .join("\n\n");
}

/**
 * Convert EditorJS OutputData to HTML
 */
export function docToHtml(content: OutputData): string {
  const htmlBlocks = content.blocks.map((block) => {
    switch (block.type) {
      case "header":
        return `<h${(block.data as any).level}>${(block.data as any).text}</h${(block.data as any).level}>`;

      case "paragraph":
        return `<p>${(block.data as any).text}</p>`;

      case "list":
        const items = ((block.data as any).items as Array<{ content: string }>)
          .map((item) => `<li>${item.content}</li>`)
          .join("\n");

        if ((block.data as any).style === "ordered") {
          return `<ol>\n${items}\n</ol>`;
        } else {
          return `<ul>\n${items}\n</ul>`;
        }

      case "code":
        return `<pre><code>${(block.data as any).code}</code></pre>`;

      case "quote":
        return `<blockquote>${(block.data as any).text}</blockquote>`;

      case "delimiter":
        return `<hr />`;

      case "image":
        return `<img src="${(block.data as any).file.url}" alt="${(block.data as any).caption || ""}" />`;

      default:
        return "";
    }
  });

  return `<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <style>
    body { font-family: Arial, sans-serif; line-height: 1.6; margin: 20px; }
    h1, h2, h3 { margin-top: 20px; }
    code { background-color: #f0f0f0; padding: 2px 6px; border-radius: 3px; }
    pre { background-color: #f0f0f0; padding: 10px; border-radius: 5px; overflow-x: auto; }
    blockquote { border-left: 4px solid #ddd; padding-left: 10px; color: #666; }
  </style>
</head>
<body>
${htmlBlocks.join("\n")}
</body>
</html>`;
}

/**
 * Export a Doc entity as JSON
 */
export function exportDocAsJson(doc: DocEntity): string {
  return JSON.stringify(
    {
      name: doc.name,
      type: "doc",
      content: doc.content,
      createdAt: new Date(doc.createdAt).toISOString(),
      updatedAt: new Date(doc.updatedAt).toISOString(),
    },
    null,
    2,
  );
}

/**
 * Export a Doc entity as Markdown
 */
export function exportDocAsMarkdown(doc: DocEntity): string {
  const header = `# ${doc.name}\n\nCreated: ${new Date(doc.createdAt).toISOString()}\nUpdated: ${new Date(doc.updatedAt).toISOString()}\n\n---\n\n`;
  const content = docToMarkdown(doc.content);
  return header + content;
}

/**
 * Export a Doc entity as HTML
 */
export function exportDocAsHtml(doc: DocEntity): string {
  const html = docToHtml(doc.content);
  const headerHtml = `<h1>${doc.name}</h1><p>Created: ${new Date(doc.createdAt).toISOString()}\nUpdated: ${new Date(doc.updatedAt).toISOString()}</p><hr />`;

  // Insert header before the first body element
  return html
    .replace("</head>", `<title>${doc.name}</title>\n</head>`)
    .replace("<body>", `<body>\n${headerHtml}\n`);
}

/**
 * Export a Todo entity as JSON
 */
export function exportTodoAsJson(todo: TodoEntity): string {
  return JSON.stringify(
    {
      name: todo.name,
      type: "todo",
      config: todo.config,
      tags: todo.tags,
      tasks: todo.tasks,
      createdAt: new Date(todo.createdAt).toISOString(),
      updatedAt: new Date(todo.updatedAt).toISOString(),
    },
    null,
    2,
  );
}

/**
 * Export a Todo entity as CSV
 */
export function exportTodoAsCsv(todo: TodoEntity): string {
  const headers = [
    "Title",
    "Description",
    "Status",
    "Tags",
    "Created",
    "Updated",
  ];
  const rows = Object.values(todo.tasks).map((task) => [
    task.title,
    task.description || "",
    todo.config.statuses.find((s) => s.id === task.statusId)?.name || "",
    task.tagIds.map((id) => todo.tags[id]?.name || "").join(";"),
    new Date(task.createdAt).toISOString(),
    new Date(task.updatedAt).toISOString(),
  ]);

  const csvContent = [
    headers.join(","),
    ...rows.map((row) =>
      row.map((cell) => `"${String(cell).replace(/"/g, '""')}"`).join(","),
    ),
  ].join("\n");

  return csvContent;
}

/**
 * Export a Todo entity as Markdown
 */
export function exportTodoAsMarkdown(todo: TodoEntity): string {
  let markdown = `# ${todo.name}\n\nCreated: ${new Date(todo.createdAt).toISOString()}\nUpdated: ${new Date(todo.updatedAt).toISOString()}\n\n`;

  // Group tasks by status
  const tasksByStatus: Record<string, typeof todo.tasks> = {};
  for (const status of todo.config.statuses) {
    tasksByStatus[status.id] = {};
  }

  for (const [taskId, task] of Object.entries(todo.tasks)) {
    const statusId = task.statusId;
    if (!tasksByStatus[statusId]) {
      tasksByStatus[statusId] = {};
    }
    tasksByStatus[statusId][taskId] = task;
  }

  // Add tasks by status
  for (const status of todo.config.statuses) {
    markdown += `## ${status.name}\n\n`;
    const tasks = tasksByStatus[status.id];
    if (Object.keys(tasks).length === 0) {
      markdown += "- (No tasks)\n\n";
    } else {
      for (const task of Object.values(tasks)) {
        const tags = task.tagIds
          .map((id) => todo.tags[id]?.name || "")
          .filter((n) => n)
          .join(", ");
        markdown += `- **${task.title}**${tags ? ` (${tags})` : ""}`;
        if (task.description) {
          markdown += `\n  - ${task.description}`;
        }
        markdown += "\n";
      }
    }
    markdown += "\n";
  }

  return markdown;
}

/**
 * Export entire workspace as JSON
 */
export function exportWorkspaceAsJson(workspace: Workspace): string {
  return JSON.stringify(workspace, null, 2);
}

/**
 * Trigger download of a file
 */
export function downloadFile(
  content: string,
  filename: string,
  mimeType: string = "text/plain",
): void {
  const blob = new Blob([content], { type: mimeType });
  const url = URL.createObjectURL(blob);
  const link = document.createElement("a");
  link.href = url;
  link.download = filename;
  document.body.appendChild(link);
  link.click();
  document.body.removeChild(link);
  URL.revokeObjectURL(url);
}

/**
 * Export any entity based on its type
 */
export function exportEntity(
  entity: Entity,
  format: "json" | "markdown" | "html" | "csv",
): string {
  if (entity.type === "doc") {
    switch (format) {
      case "json":
        return exportDocAsJson(entity);
      case "markdown":
        return exportDocAsMarkdown(entity);
      case "html":
        return exportDocAsHtml(entity);
      default:
        return exportDocAsJson(entity);
    }
  } else if (entity.type === "todo") {
    switch (format) {
      case "json":
        return exportTodoAsJson(entity);
      case "markdown":
        return exportTodoAsMarkdown(entity);
      case "csv":
        return exportTodoAsCsv(entity);
      default:
        return exportTodoAsJson(entity);
    }
  }

  return "";
}