import { tool, type Tool } from "ai";
import { z } from "zod";

/**
 * Catalog of Tiptap editor commands exposed to the AI agent.
 *
 * Each entry pairs:
 *   - an AI SDK tool definition (description + zod input schema)
 *   - safety metadata used to build the system prompt dynamically
 *     (category, selectionEffect, destructive)
 *
 * The frontend's agent executor dispatches on `name` and calls
 * `editor.chain()[command](args).run()`, so the catalog is the single
 * source of truth for what the agent can do.
 *
 * Inspired by `tiptap-apcore`'s Registry + AnnotationCatalog pattern,
 * but intentionally pared down to the ~15 commands that make sense for
 * a research article editor.
 */

type Category = "query" | "selection" | "format" | "content";

/**
 * How a command interacts with the current text selection.
 *
 * - `require`: must have a non-collapsed selection (mark toggles)
 * - `preserve`: selection survives execution (most mark toggles, alignment)
 * - `destroy`: cursor collapses after execution (insertContent)
 * - `none`: operates on the block at cursor, no selection needed
 */
type SelectionEffect = "require" | "preserve" | "destroy" | "none";

// `tool()` returns a strongly-typed Tool<InputSchema, Output>; storing them
// in a homogeneous array requires the most permissive Tool generic.
type AnyTool = Tool<any, any>;

export interface TiptapCommandEntry {
  name: string;
  category: Category;
  selectionEffect: SelectionEffect;
  destructive: boolean;
  tool: AnyTool;
}

// ---------------------------------------------------------------------------
// Command entries
// ---------------------------------------------------------------------------

export const TIPTAP_COMMANDS: TiptapCommandEntry[] = [
  // -- Selection ---------------------------------------------------------
  {
    name: "selectText",
    category: "selection",
    selectionEffect: "preserve",
    destructive: false,
    tool: tool({
      description:
        "Find a text substring in the document and select it. Use this BEFORE applying " +
        "mark-level formatting commands (toggleBold, setLink, etc.). Returns { found, from, to } " +
        "so you can verify the match. When the same text appears multiple times, use `occurrence` " +
        "(1-based) or provide `contextBefore` / `contextAfter` to disambiguate.",
      inputSchema: z.object({
        text: z.string().describe("The exact text to select (substring match)"),
        occurrence: z
          .number()
          .int()
          .min(1)
          .optional()
          .describe(
            "Which occurrence to select (1-based). Defaults to 1. Ignored if contextBefore/After are provided.",
          ),
        contextBefore: z
          .string()
          .optional()
          .describe("A few words appearing just before the target text, used to disambiguate."),
        contextAfter: z
          .string()
          .optional()
          .describe("A few words appearing just after the target text, used to disambiguate."),
      }),
    }),
  },

  // -- Format: marks (require selection) --------------------------------
  {
    name: "toggleBold",
    category: "format",
    selectionEffect: "require",
    destructive: false,
    tool: tool({
      description:
        "Toggle bold on the current selection. MUST be called after selectText - has no effect without an active text range.",
      inputSchema: z.object({}),
    }),
  },
  {
    name: "toggleItalic",
    category: "format",
    selectionEffect: "require",
    destructive: false,
    tool: tool({
      description:
        "Toggle italic on the current selection. MUST be called after selectText - has no effect without an active text range.",
      inputSchema: z.object({}),
    }),
  },
  {
    name: "toggleStrike",
    category: "format",
    selectionEffect: "require",
    destructive: false,
    tool: tool({
      description:
        "Toggle strikethrough on the current selection. MUST be called after selectText.",
      inputSchema: z.object({}),
    }),
  },
  {
    name: "toggleCode",
    category: "format",
    selectionEffect: "require",
    destructive: false,
    tool: tool({
      description:
        "Toggle inline code formatting on the current selection. MUST be called after selectText.",
      inputSchema: z.object({}),
    }),
  },
  {
    name: "setLink",
    category: "format",
    selectionEffect: "require",
    destructive: false,
    tool: tool({
      description:
        "Turn the current selection into a hyperlink. MUST be called after selectText. " +
        "Only http(s)/mailto/tel/relative URLs are accepted.",
      inputSchema: z.object({
        href: z.string().describe("Target URL (http/https/mailto/tel or relative)"),
      }),
    }),
  },
  {
    name: "unsetLink",
    category: "format",
    selectionEffect: "require",
    destructive: false,
    tool: tool({
      description: "Remove hyperlink formatting from the current selection.",
      inputSchema: z.object({}),
    }),
  },

  // -- Format: node-level (no selection needed) -------------------------
  {
    name: "toggleHeading",
    category: "format",
    selectionEffect: "none",
    destructive: false,
    tool: tool({
      description:
        "Convert the block at the cursor to a heading (or back to a paragraph if already that level). " +
        "Operates on the containing block - no text selection needed.",
      inputSchema: z.object({
        level: z.number().int().min(1).max(3).describe("Heading level (1, 2 or 3)"),
      }),
    }),
  },
  {
    name: "setParagraph",
    category: "format",
    selectionEffect: "none",
    destructive: false,
    tool: tool({
      description: "Convert the block at the cursor to a plain paragraph.",
      inputSchema: z.object({}),
    }),
  },
  {
    name: "toggleBulletList",
    category: "format",
    selectionEffect: "none",
    destructive: false,
    tool: tool({
      description: "Toggle the block at the cursor between a bullet list item and a paragraph.",
      inputSchema: z.object({}),
    }),
  },
  {
    name: "toggleOrderedList",
    category: "format",
    selectionEffect: "none",
    destructive: false,
    tool: tool({
      description: "Toggle the block at the cursor between an ordered (numbered) list item and a paragraph.",
      inputSchema: z.object({}),
    }),
  },
  {
    name: "toggleBlockquote",
    category: "format",
    selectionEffect: "none",
    destructive: false,
    tool: tool({
      description: "Toggle blockquote on the block at the cursor.",
      inputSchema: z.object({}),
    }),
  },
  {
    name: "toggleCodeBlock",
    category: "format",
    selectionEffect: "none",
    destructive: false,
    tool: tool({
      description:
        "Toggle code block on the block at the cursor. Use for multi-line code snippets.",
      inputSchema: z.object({
        language: z
          .string()
          .optional()
          .describe("Language hint for syntax highlighting (e.g. 'python', 'typescript')"),
      }),
    }),
  },
];

// ---------------------------------------------------------------------------
// Helpers
// ---------------------------------------------------------------------------

/** AI SDK tool definitions keyed by command name. Pass directly to streamText. */
export function buildTiptapTools(): Record<string, AnyTool> {
  const out: Record<string, AnyTool> = {};
  for (const entry of TIPTAP_COMMANDS) {
    out[entry.name] = entry.tool;
  }
  return out;
}

/** Commands grouped by how they interact with the selection. */
export function classifyBySelectionEffect(): Record<SelectionEffect, string[]> {
  const groups: Record<SelectionEffect, string[]> = {
    require: [],
    preserve: [],
    destroy: [],
    none: [],
  };
  for (const entry of TIPTAP_COMMANDS) {
    groups[entry.selectionEffect].push(entry.name);
  }
  return groups;
}

/** Commands grouped by category, used to build a concise command list in the prompt. */
export function groupByCategory(): Record<Category, string[]> {
  const groups: Record<Category, string[]> = {
    query: [],
    selection: [],
    format: [],
    content: [],
  };
  for (const entry of TIPTAP_COMMANDS) {
    groups[entry.category].push(entry.name);
  }
  return groups;
}