/**
 * memorize — write or overwrite a playbook document.
 *
 * Three modes, selected by which parameters are set:
 * - note:      title (+tags) → flat file `<slug>.md` at the playbook root
 * - skill:     name + description → `<slug>/SKILL.md` bundle entry point
 * - companion: name + file → `<slug>/<file>` (raw body, no frontmatter)
 */

import { tool, type Tool, type ToolsProviderController } from "@lmstudio/sdk";
// @ts-ignore — zod/lib re-export chain breaks with NodeNext; runtime is fine
import { z } from "zod";
import path from "node:path";
import fs from "node:fs";
import type { IndexManager } from "../indexManager.js";
import { formatToolMetaBlock } from "../helpers/pluginMeta.js";

function slugify(title: string): string {
  return title
    .toLowerCase()
    .normalize("NFD")
    .replace(/[\u0300-\u036f]/g, "")  // strip diacritics
    .replace(/[^\w\s-]/g, "")
    .trim()
    .replace(/[\s_]+/g, "-")
    .replace(/-+/g, "-")
    .slice(0, 80);
}

/** Reject absolute paths, `..` traversal, and anything outside the supported .md/.txt extensions. */
function sanitizeRelativeFile(file: string): string | null {
  if (!file || path.isAbsolute(file)) return null;
  const normalized = path.normalize(file);
  if (normalized === "." || normalized.split(path.sep).some((part) => part === "..")) return null;
  const ext = path.extname(normalized).toLowerCase();
  if (ext !== ".md" && ext !== ".txt") return null;
  return normalized;
}

function readExistingCreated(filePath: string): string | undefined {
  if (!fs.existsSync(filePath)) return undefined;
  const existing = fs.readFileSync(filePath, "utf8");
  const m = existing.match(/^created:\s*"?([^"\n]+)"?/m);
  return m ? m[1].trim() : undefined;
}

function buildFrontmatter(title: string, tags: string[], now: string, existingCreated?: string): string {
  const created = existingCreated ?? now;
  const tagList = tags.map((t) => `"${t}"`).join(", ");
  return `---\ntitle: "${title}"\ntags: [${tagList}]\ncreated: "${created}"\nupdated: "${now}"\n---\n\n`;
}

function buildSkillFrontmatter(name: string, description: string, now: string, existingCreated?: string): string {
  const created = existingCreated ?? now;
  const esc = (s: string) => s.replace(/"/g, '\\"');
  return `---\nname: "${esc(name)}"\ndescription: "${esc(description)}"\ncreated: "${created}"\nupdated: "${now}"\n---\n\n`;
}

export function createMemorizeTool(
  _ctl: ToolsProviderController,
  index: IndexManager
): Tool {
  return tool({
    name: "memorize",
    description: `Write a new document to the playbook, or completely replace an existing one. Supports plain notes and SKILL.md skill bundles.

Three modes, chosen by which parameters you set:
- Note: set \`title\` (+ optional \`tags\`). Writes a flat file \`<slug>.md\` at the playbook root with title/tags/created/updated frontmatter.
- Skill: set \`name\` + \`description\`. Writes \`<slug>/SKILL.md\` with name/description/created/updated frontmatter — the entry point recall/read will surface.
- Companion file: set \`name\` + \`file\` (e.g. "tools/my-tool.md"). Writes \`<slug>/<file>\` as plain Markdown with no frontmatter — link to it from SKILL.md's body with a relative path. Not indexed by recall; fetch it directly with read once its path is known.

The filename/folder name is always derived by slugifying \`title\` or \`name\`.
When multiple Playbook Directories are configured, new documents are always written to the first (primary) one; the others are read-only search/read sources.

Use this tool when:
- The user explicitly asks you to remember something
- You derive or discover information useful for future conversations
- Summarising the outcome of a completed task
- Creating a structured reference note (how-tos, decisions, preferences)
- Authoring or updating a reusable skill bundle for future sessions

Returns:
- Confirmation with the resulting relative path
- An error if required parameters for the selected mode are missing

Examples:
- title: "API Auth Strategy", tags: ["api", "auth"], body: "Use OAuth2 for..." → note
- name: "pdf-report", description: "Generate paginated PDF reports from tabular data.", body: "# PDF Report Skill\n..." → pdf-report/SKILL.md
- name: "pdf-report", file: "tools/render_table.md", body: "# render_table\n..." → pdf-report/tools/render_table.md

${formatToolMetaBlock()}`,
    parameters: {
      title: z
        .string()
        .optional()
        .describe("Document title for a plain note. Required unless `name` is set (skill mode)."),
      name: z
        .string()
        .optional()
        .describe(
          "Skill identifier (kebab-case recommended). When set, targets a skill bundle folder instead of a flat note. Combine with `description` to write SKILL.md, or with `file` to write a companion file."
        ),
      file: z
        .string()
        .optional()
        .describe(
          'Relative path inside the skill bundle for a companion file, e.g. "tools/my-tool.md". Requires `name`. Written as-is with no frontmatter.'
        ),
      description: z
        .string()
        .optional()
        .describe(
          "One-paragraph discovery description. Required when writing SKILL.md (name set, file omitted) — this is what recall shows before the full file is read."
        ),
      tags: z
        .array(z.string())
        .default([])
        .describe("List of tags to categorise this document. Only used for plain notes."),
      body: z
        .string()
        .describe("The main content of the document (plain Markdown, without frontmatter)."),
    },
    implementation: async (args) => {
      const now = new Date().toISOString();

      if (args.name) {
        const slug = slugify(args.name);
        if (!slug) return "Error: name must contain at least one word character.";
        const skillDir = path.join(index.getPlaybookDirectory(), slug);

        if (args.file) {
          const rel = sanitizeRelativeFile(args.file);
          if (!rel) return `Error: invalid file "${args.file}" — must be a relative .md/.txt path without "..".`;
          const filePath = path.join(skillDir, rel);
          await index.writeFile(filePath, args.body);
          return `Saved companion file → ${slug}/${rel}`;
        }

        if (!args.description) {
          return "Error: description is required to write a SKILL.md (or pass `file` to add a companion file instead).";
        }

        const filePath = path.join(skillDir, "SKILL.md");
        const existingCreated = readExistingCreated(filePath);
        const frontmatter = buildSkillFrontmatter(args.name, args.description, now, existingCreated);
        await index.writeFile(filePath, `${frontmatter}${args.body}`);
        return `Saved skill "${args.name}" → ${slug}/SKILL.md`;
      }

      if (!args.title) {
        return "Error: title is required for a plain note (or use `name`/`description` to write a skill).";
      }

      const slug = slugify(args.title);
      if (!slug) return "Error: Title must contain at least one word character.";

      const filename = `${slug}.md`;
      const filePath = path.join(index.getPlaybookDirectory(), filename);
      const existingCreated = readExistingCreated(filePath);
      const frontmatter = buildFrontmatter(args.title, args.tags, now, existingCreated);
      await index.writeFile(filePath, `${frontmatter}${args.body}`);

      return `Saved "${args.title}" → ${filename}`;
    },
  });
}

/**
 * memorize — write or overwrite a playbook document.
 *
 * Three modes, selected by which parameters are set:
 * - note:      title (+tags) → flat file `<slug>.md` at the playbook root
 * - skill:     name + description → `<slug>/SKILL.md` bundle entry point
 * - companion: name + file → `<slug>/<file>` (raw body, no frontmatter)
 */

import { tool, type Tool, type ToolsProviderController } from "@lmstudio/sdk";
// @ts-ignore — zod/lib re-export chain breaks with NodeNext; runtime is fine
import { z } from "zod";
import path from "node:path";
import fs from "node:fs";
import type { IndexManager } from "../indexManager.js";
import { formatToolMetaBlock } from "../helpers/pluginMeta.js";

function slugify(title: string): string {
  return title
    .toLowerCase()
    .normalize("NFD")
    .replace(/[\u0300-\u036f]/g, "")  // strip diacritics
    .replace(/[^\w\s-]/g, "")
    .trim()
    .replace(/[\s_]+/g, "-")
    .replace(/-+/g, "-")
    .slice(0, 80);
}

/** Reject absolute paths, `..` traversal, and anything outside the supported .md/.txt extensions. */
function sanitizeRelativeFile(file: string): string | null {
  if (!file || path.isAbsolute(file)) return null;
  const normalized = path.normalize(file);
  if (normalized === "." || normalized.split(path.sep).some((part) => part === "..")) return null;
  const ext = path.extname(normalized).toLowerCase();
  if (ext !== ".md" && ext !== ".txt") return null;
  return normalized;
}

function readExistingCreated(filePath: string): string | undefined {
  if (!fs.existsSync(filePath)) return undefined;
  const existing = fs.readFileSync(filePath, "utf8");
  const m = existing.match(/^created:\s*"?([^"\n]+)"?/m);
  return m ? m[1].trim() : undefined;
}

function buildFrontmatter(title: string, tags: string[], now: string, existingCreated?: string): string {
  const created = existingCreated ?? now;
  const tagList = tags.map((t) => `"${t}"`).join(", ");
  return `---\ntitle: "${title}"\ntags: [${tagList}]\ncreated: "${created}"\nupdated: "${now}"\n---\n\n`;
}

function buildSkillFrontmatter(name: string, description: string, now: string, existingCreated?: string): string {
  const created = existingCreated ?? now;
  const esc = (s: string) => s.replace(/"/g, '\\"');
  return `---\nname: "${esc(name)}"\ndescription: "${esc(description)}"\ncreated: "${created}"\nupdated: "${now}"\n---\n\n`;
}

export function createMemorizeTool(
  _ctl: ToolsProviderController,
  index: IndexManager
): Tool {
  return tool({
    name: "memorize",
    description: `Write a new document to the playbook, or completely replace an existing one. Supports plain notes and SKILL.md skill bundles.

Three modes, chosen by which parameters you set:
- Note: set \`title\` (+ optional \`tags\`). Writes a flat file \`<slug>.md\` at the playbook root with title/tags/created/updated frontmatter.
- Skill: set \`name\` + \`description\`. Writes \`<slug>/SKILL.md\` with name/description/created/updated frontmatter — the entry point recall/read will surface.
- Companion file: set \`name\` + \`file\` (e.g. "tools/my-tool.md"). Writes \`<slug>/<file>\` as plain Markdown with no frontmatter — link to it from SKILL.md's body with a relative path. Not indexed by recall; fetch it directly with read once its path is known.

The filename/folder name is always derived by slugifying \`title\` or \`name\`.
When multiple Playbook Directories are configured, new documents are always written to the first (primary) one; the others are read-only search/read sources.

Use this tool when:
- The user explicitly asks you to remember something
- You derive or discover information useful for future conversations
- Summarising the outcome of a completed task
- Creating a structured reference note (how-tos, decisions, preferences)
- Authoring or updating a reusable skill bundle for future sessions

Returns:
- Confirmation with the resulting relative path
- An error if required parameters for the selected mode are missing

Examples:
- title: "API Auth Strategy", tags: ["api", "auth"], body: "Use OAuth2 for..." → note
- name: "pdf-report", description: "Generate paginated PDF reports from tabular data.", body: "# PDF Report Skill\n..." → pdf-report/SKILL.md
- name: "pdf-report", file: "tools/render_table.md", body: "# render_table\n..." → pdf-report/tools/render_table.md

${formatToolMetaBlock()}`,
    parameters: {
      title: z
        .string()
        .optional()
        .describe("Document title for a plain note. Required unless `name` is set (skill mode)."),
      name: z
        .string()
        .optional()
        .describe(
          "Skill identifier (kebab-case recommended). When set, targets a skill bundle folder instead of a flat note. Combine with `description` to write SKILL.md, or with `file` to write a companion file."
        ),
      file: z
        .string()
        .optional()
        .describe(
          'Relative path inside the skill bundle for a companion file, e.g. "tools/my-tool.md". Requires `name`. Written as-is with no frontmatter.'
        ),
      description: z
        .string()
        .optional()
        .describe(
          "One-paragraph discovery description. Required when writing SKILL.md (name set, file omitted) — this is what recall shows before the full file is read."
        ),
      tags: z
        .array(z.string())
        .default([])
        .describe("List of tags to categorise this document. Only used for plain notes."),
      body: z
        .string()
        .describe("The main content of the document (plain Markdown, without frontmatter)."),
    },
    implementation: async (args) => {
      const now = new Date().toISOString();

      if (args.name) {
        const slug = slugify(args.name);
        if (!slug) return "Error: name must contain at least one word character.";
        const skillDir = path.join(index.getPlaybookDirectory(), slug);

        if (args.file) {
          const rel = sanitizeRelativeFile(args.file);
          if (!rel) return `Error: invalid file "${args.file}" — must be a relative .md/.txt path without "..".`;
          const filePath = path.join(skillDir, rel);
          await index.writeFile(filePath, args.body);
          return `Saved companion file → ${slug}/${rel}`;
        }

        if (!args.description) {
          return "Error: description is required to write a SKILL.md (or pass `file` to add a companion file instead).";
        }

        const filePath = path.join(skillDir, "SKILL.md");
        const existingCreated = readExistingCreated(filePath);
        const frontmatter = buildSkillFrontmatter(args.name, args.description, now, existingCreated);
        await index.writeFile(filePath, `${frontmatter}${args.body}`);
        return `Saved skill "${args.name}" → ${slug}/SKILL.md`;
      }

      if (!args.title) {
        return "Error: title is required for a plain note (or use `name`/`description` to write a skill).";
      }

      const slug = slugify(args.title);
      if (!slug) return "Error: Title must contain at least one word character.";

      const filename = `${slug}.md`;
      const filePath = path.join(index.getPlaybookDirectory(), filename);
      const existingCreated = readExistingCreated(filePath);
      const frontmatter = buildFrontmatter(args.title, args.tags, now, existingCreated);
      await index.writeFile(filePath, `${frontmatter}${args.body}`);

      return `Saved "${args.title}" → ${filename}`;
    },
  });
}