import { optionalEnum, optionalLimit, optionalText, requireString } from "./agent-tool-args";
import { holdForReview } from "./agent-deliverable-tools";
import { reviewsDeliverables } from "./held-deliverables";
import type { AgentToolContext, AgentToolDeps } from "./agent-tools";
import { DocumentService } from "./document-service";
import type { JsonRecord } from "./provider-http";
import type { ToolDefinition } from "./provider-tool-turn";
import { relevantItems } from "./relevance";
import { PAGE_TOOL_PROPERTIES, pageText, readPageArgs } from "./text-paging";

const PAGE_ARGUMENTS = ["version", "start_line", "line_count", "start_column", "search"] as const;

export const DOCUMENT_TYPES = ["prd", "spec", "memo", "report", "runbook", "proposal", "policy", "guide"] as const;

interface DocumentRow {
  id: string;
  title: string;
  doc_type: string;
  status: string;
  content: string;
  version: number;
  updated_at: string;
  task_id: string | null;
  task_title: string | null;
}

export const DOCUMENT_TOOLS: ToolDefinition[] = [
  {
    name: "list_documents",
    description: "Find company documents (PRDs, specs, reports, ...) by words in their title or body, or by type. Returns doc_ids for read_document.",
    parameters: {
      type: "object",
      additionalProperties: false,
      properties: {
        query: { type: "string", description: "Words to look for; omit to list the newest documents." },
        doc_type: { type: "string", enum: [...DOCUMENT_TYPES] },
        limit: { type: "number", description: "Most documents to return (default 10, max 30)." },
      },
      required: [],
    },
  },
  {
    name: "read_document",
    description: "Read a company document by doc_id — whole, a range of lines, or only the lines matching a search. Pass version to read an earlier version; pass history=true to list every version.",
    parameters: {
      type: "object",
      additionalProperties: false,
      properties: {
        doc_id: { type: "string" },
        version: { type: "number", description: "An earlier version number; omit for the current one." },
        history: { type: "boolean", description: "List every version with who changed it and why." },
        ...PAGE_TOOL_PROPERTIES,
      },
      required: ["doc_id"],
    },
  },
  {
    name: "update_document",
    description: "Replace a company document's content (and optionally its title). Say why in reason.",
    parameters: {
      type: "object",
      additionalProperties: false,
      properties: {
        doc_id: { type: "string" },
        content: { type: "string", description: "The full new content in markdown." },
        title: { type: "string" },
        reason: { type: "string", description: "What changed and why." },
      },
      required: ["doc_id", "content", "reason"],
    },
  },
];

export function listDocumentsTool(deps: AgentToolDeps, ctx: AgentToolContext, args: JsonRecord): string {
  const query = optionalText(args.query, "query");
  const docType = args.doc_type === undefined ? null : optionalEnum(args.doc_type, "doc_type", DOCUMENT_TYPES, "");
  const limit = optionalLimit(args.limit, "limit", 10, 30);
  const rows = deps.db.prepare(`
    select d.id, d.title, d.doc_type, d.status, d.content, d.version, d.updated_at, d.task_id, t.title as task_title
    from documents d left join tasks t on t.id = d.task_id
    where d.org_id = ? and (? is null or d.doc_type = ?) order by d.updated_at desc
  `).all(ctx.orgId, docType, docType) as unknown as DocumentRow[];
  const found = query ? relevantItems(rows, (row) => `${row.title} ${row.content}`, query, limit) : rows.slice(0, limit);
  if (found.length === 0) return query ? `No documents match "${query}".` : "No documents yet.";
  return found.map((row) => `${row.title} (doc_id=${row.id}, ${row.doc_type}, ${row.status}, v${row.version}, ${row.content.length} chars, updated ${row.updated_at}${producedBy(row)})`).join("\n");
}

export function readDocumentTool(deps: AgentToolDeps, ctx: AgentToolContext, args: JsonRecord): string {
  const id = requireString(args.doc_id, "doc_id");
  const page = readPageArgs(args);
  if (args.history !== undefined && typeof args.history !== "boolean") throw new Error('"history" must be true or false.');
  const doc = deps.db.prepare("select doc_type, version from documents where id = ? and org_id = ?")
    .get(id, ctx.orgId) as { doc_type: string; version: number } | undefined;
  const versions = new DocumentService(deps.db).versions(ctx.orgId, id);
  if (versions.length === 0) throw new Error(`No document with doc_id "${id}".`);
  const latest = versions[versions.length - 1].version;
  const kind = doc ? doc.doc_type : "deleted";
  if (args.history === true) {
    if (PAGE_ARGUMENTS.some((name) => args[name] !== undefined)) {
      throw new Error("history=true lists versions; it takes no version or paging arguments.");
    }
    return versions.map((v) => `v${v.version} ${v.created_at} by ${v.changed_by_type}${v.changed_by_id ? ` ${v.changed_by_id}` : ""} — ${v.reason} (${v.content.length} chars)`).join("\n");
  }
  const wanted = optionalLimit(args.version, "version", latest, latest);
  const picked = versions.find((v) => v.version === wanted);
  if (!picked) throw new Error(`Document ${id} has no version ${wanted}.`);
  return `${picked.title} (${kind}, ${picked.status}, v${picked.version} of ${latest})\n\n${pageText(picked.title, picked.content, page)}`;
}

export function updateDocumentTool(deps: AgentToolDeps, ctx: AgentToolContext, args: JsonRecord): string {
  const id = requireString(args.doc_id, "doc_id");
  const doc = deps.db.prepare("select title, doc_type, status, version from documents where id = ? and org_id = ?")
    .get(id, ctx.orgId) as { title: string; doc_type: string; status: string; version: number } | undefined;
  if (!doc) throw new Error(`No document with doc_id "${id}".`);
  const content = requireString(args.content, "content");
  const title = optionalText(args.title, "title") ?? doc.title;
  const reason = requireString(args.reason, "reason");
  if (reviewsDeliverables(deps.db, ctx.orgId)) {
    holdForReview(deps, ctx, { kind: "document_update", documentId: id, baseVersion: doc.version, title, reason }, content, `Review ${doc.doc_type} update: ${title}`);
    return `The update to "${title}" is held for board review in Approvals. The document keeps its current version until the update is approved.`;
  }
  const version = new DocumentService(deps.db).update({
    orgId: ctx.orgId, documentId: id, title, content, status: doc.status, reason, changedByType: "agent", changedById: ctx.agent.id,
  });
  return `Updated document "${title}" to v${version} (doc_id=${id}).`;
}

function producedBy(row: DocumentRow): string {
  if (row.task_id === null || row.task_title === null) return "";
  return `, from task "${row.task_title}" task_id=${row.task_id}`;
}