package com.ankurm.lg4j;

import org.bsc.langgraph4j.state.AgentState;
import org.bsc.langgraph4j.state.Channel;
import org.bsc.langgraph4j.state.Channels;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;

/**
 * The shared state every node reads and writes.
 *
 * <p>State is just a {@code Map<String,Object>} with typed accessors. A key with an
 * <em>appender</em> channel ({@code trail}) accumulates values; any other key is
 * overwritten by the latest node that writes it.
 */
public class LoanState extends AgentState {

    public static final String APPLICANT = "applicant";
    public static final String AMOUNT = "amount";
    public static final String INCOME = "income";
    public static final String CREDIT_SCORE = "creditScore";
    public static final String RISK = "risk";
    public static final String DECISION = "decision";
    public static final String TRAIL = "trail";

    /** Channel schema: {@code trail} appends, everything else replaces. */
    public static final Map<String, Channel<?>> SCHEMA =
            Map.of(TRAIL, Channels.appender(ArrayList::new));

    public LoanState(Map<String, Object> data) {
        super(data);
    }

    public String applicant() { return this.<String>value(APPLICANT).orElse("?"); }
    public int amount() { return this.<Integer>value(AMOUNT).orElse(0); }
    public int income() { return this.<Integer>value(INCOME).orElse(0); }
    public int creditScore() { return this.<Integer>value(CREDIT_SCORE).orElse(0); }
    public String risk() { return this.<String>value(RISK).orElse("UNKNOWN"); }
    public String decision() { return this.<String>value(DECISION).orElse("PENDING"); }
    public List<String> trail() { return this.<List<String>>value(TRAIL).orElse(List.of()); }
}