import type { Db } from "../db/database.js";
import { createModelRow, deleteModelRow, getModel, resolveCompany, updateModelCell } from "../db/queries.js";
import { fail, ok } from "./result.js";
import type { RpcHandlers } from "./types.js";

function errorDetail(operation: string, error: unknown): { operation: string; message?: string } {
  return {
    operation,
    message: error instanceof Error ? error.message : undefined,
  };
}

export function modelHandlers(db: Db): RpcHandlers<"model.get" | "model.updateCell" | "model.createRow" | "model.deleteRow" | "model.runScenario"> {
  return {
    "model.get": ({ companyId, tab }) => {
      const company = resolveCompany(db, companyId);
      if (!company) return fail("NOT_FOUND", `Company "${companyId}" not found.`);
      try {
        return ok("model.get", getModel(db, company.id, tab));
      } catch (error) {
        return fail("INTERNAL_ERROR", "Could not load model for company.", errorDetail("getModel", error));
      }
    },
    "model.updateCell": ({ companyId, tab, row, col, value }) => {
      const company = resolveCompany(db, companyId);
      if (!company) return fail("NOT_FOUND", `Company "${companyId}" not found.`);
      return ok("model.updateCell", updateModelCell(db, company.id, tab, row, col, value));
    },
    "model.createRow": ({ companyId, tab, label, kind, values }) => {
      const company = resolveCompany(db, companyId);
      if (!company) return fail("NOT_FOUND", `Company "${companyId}" not found.`);
      return ok("model.createRow", createModelRow(db, company.id, tab, { label, kind, values: values ?? [] }));
    },
    "model.deleteRow": ({ companyId, tab, row }) => {
      const company = resolveCompany(db, companyId);
      if (!company) return fail("NOT_FOUND", `Company "${companyId}" not found.`);
      return ok("model.deleteRow", { ok: deleteModelRow(db, company.id, tab, row) });
    },
    "model.runScenario": ({ companyId, overrides }) => {
      const company = resolveCompany(db, companyId);
      if (!company) return fail("NOT_FOUND", `Company "${companyId}" not found.`);
      const model = getModel(db, company.id, "operating");
      const rows = model.rows.map((row, rowIndex) => ({
        ...row,
        values: row.values.map((value, colIndex) => overrides[`${rowIndex}-${colIndex}`] ?? value),
      }));
      return ok("model.runScenario", { headers: model.headers, rows });
    },
  };
}