// progression-chain-read — full state-of-chain for one deal, by chainId or
// address. Links are priority-ordered; a priority gap or duplicate is flagged
// at read time, not silently passed. Read-only.

import { z } from "zod";
import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { lifelineTool } from "../../../../../../../platform/lib/mcp-lifeline/dist/index.js";
import { getSession } from "../lib/neo4j.js";
import { readChain, DEFAULT_STALLED_THRESHOLD_DAYS } from "../lib/chain-graph.js";

export function registerChainRead(server: McpServer, accountId: string): void {
  lifelineTool(
    server,
    "progression-chain-read",
    "Read the full state of one sale-agreed chain — the Sale, the Chain, every link ordered by priority with its ten milestone dates and party roles, plus a stall flag and any structural warnings (priority gap or duplicate). Select by chainId or by a link address. Read-only.",
    {
      chainId: z.string().optional().describe("The chain to read."),
      address: z.string().optional().describe("A link address to resolve the chain from (when chainId is unknown)."),
      stalledThresholdDays: z
        .number()
        .int()
        .positive()
        .optional()
        .describe(`Days with no milestone movement before 'stalled' (default ${DEFAULT_STALLED_THRESHOLD_DAYS}).`),
    },
    async (params: Record<string, unknown>) => {
      const { chainId, address, stalledThresholdDays } = params as {
        chainId?: string;
        address?: string;
        stalledThresholdDays?: number;
      };
      if (!chainId && !address) {
        return {
          content: [{ type: "text" as const, text: "Error: one of chainId or address is required." }],
          isError: true,
        };
      }
      const session = getSession();
      try {
        const state = await readChain(
          session,
          accountId,
          { chainId, address },
          Date.now(),
          stalledThresholdDays ?? DEFAULT_STALLED_THRESHOLD_DAYS,
        );
        if (!state) {
          console.error(`[progression] op=chain-read chainId=${chainId ?? address} links=0 stalled=false cause=not-found`);
          return { content: [{ type: "text" as const, text: JSON.stringify({ ok: false, found: false }, null, 2) }] };
        }
        console.error(
          `[progression] op=chain-read chainId=${state.chainId} links=${state.links.length} stalled=${state.stalled} cause=${state.structuralFlags.length ? state.structuralFlags.join(";") : state.cause}`,
        );
        return { content: [{ type: "text" as const, text: JSON.stringify({ ok: true, found: true, ...state }, null, 2) }] };
      } catch (err) {
        const msg = err instanceof Error ? err.message : String(err);
        return { content: [{ type: "text" as const, text: `Error: ${msg}` }], isError: true };
      } finally {
        await session.close();
      }
    },
  );
}