source: tags/1.2.0/AI Template/Project/Empire.cs

using System;
using System.Collections.Generic;
using CevoAILib;
using CevoAILib.Diplomacy;

namespace AI
{
        sealed class Empire : AEmpire
        {
                Random random = new Random();

                public Empire(int nationID, IntPtr serverPtr, IntPtr dataPtr, bool isNewGame)
                        : base(nationID, serverPtr, dataPtr, isNewGame)
                {
                }

                protected override void NewGame()
                {
                }

                protected override void Resume()
                {
                }

                protected override void OnTurn()
                {
                        // check if research complete
                        if (HadEvent__Turn(EmpireEvent.ResearchComplete))
                        {
                                if (random.Next(20) == 0)
                                { // start military research
                                        Blueprint.SetDomain__Turn(ModelDomain.Ground);
                                        Blueprint.SetProperty__Turn(ModelProperty.Weapons, 3);
                                        Blueprint.SetProperty__Turn(ModelProperty.Armor, 1);
                                        Blueprint.SetProperty__Turn(ModelProperty.Mobility, Blueprint.Stage.MaximumWeight - Blueprint.Weight);
                                        SetResearch__Turn(Advance.MilitaryResearch);
                                }
                                else
                                { // set random research
                                        Advance newResearch = Advance.None;
                                        int count = 0;
                                        for (Advance testResearch = Advance.FirstCommon; testResearch <= Advance.LastFuture; testResearch++)
                                        {
                                                if (CanSetResearch__Turn(testResearch))
                                                {
                                                        count++;
                                                        if (random.Next(count) == 0)
                                                                newResearch = testResearch;
                                                }
                                        }
                                        if (newResearch != Advance.None)
                                                SetResearch__Turn(newResearch);
                                }
                        }

                        // check cities
                        foreach (City city in Cities)
                        {
                                if (city.Size < 4)
                                        city.OptimizeExploitedLocations__Turn(ResourceWeights.MaxGrowth);
                                else
                                        city.OptimizeExploitedLocations__Turn(ResourceWeights.HurryProduction);
                        }

                        // move units
                        foreach (Unit unit in Units)
                        {
                                OtherLocation[] neighborLocations = unit.Location.Neighbors;
                                if (neighborLocations.Length > 0)
                                        unit.MoveTo__Turn(neighborLocations[random.Next(neighborLocations.Length)].Location); // move unit to random adjacent location
                        }
                }

                protected override void OnStealAdvance(Advance[] selection)
                {
                        StealAdvance__Turn(selection[random.Next(selection.Length)]);
                }

                protected override void OnChanceToNegotiate(Phase situation, Nation Opponent, ref bool wantNegotiation, ref bool cancelTreatyIfRejected)
                {
                        if (situation == Phase.BeginOfTurn) // start negotiation?
                        {
                                if (random.Next(30) == 0)
                                        wantNegotiation = true;
                        }
                        if (situation == Phase.ForeignTurn) // accept contact for negotiation?
                        {
                                if (random.Next(2) == 0)
                                        wantNegotiation = true;
                        }
                }

                protected override void OnNegotiate(Negotiation negotiation)
                {
                        if (negotiation.History.Count == 0 && RelationTo(negotiation.Opponent) < Relation.Alliance)
                                negotiation.SetOurNextStatement(new SuggestTrade(new ITradeItem[] { new ChangeRelation(RelationTo(negotiation.Opponent) + 1) }, null)); // suggest better treaty
                        if (negotiation.History.Count > 0 && negotiation.History[0].OpponentResponse is SuggestTrade)
                        {
                                SuggestTrade trade = negotiation.History[0].OpponentResponse as SuggestTrade;
                                if ((trade.Offers.Length == 1 && trade.Wants.Length == 0 && trade.Offers[0] is ChangeRelation &&
                                        ((ChangeRelation)trade.Offers[0]).NewRelation > RelationTo(negotiation.Opponent) ||
                                        (trade.Offers.Length == 0 && trade.Wants.Length == 1 && trade.Wants[0] is ChangeRelation &&
                                        ((ChangeRelation)trade.Wants[0]).NewRelation > RelationTo(negotiation.Opponent))))
                                        negotiation.SetOurNextStatement(new AcceptTrade()); // accept better treaty
                        }
                }

                protected override void OnForeignMove(IUnitInfo unit, Location destination)
                {
                }

                protected override void OnBeforeForeignAttack(IUnitInfo attacker, Location target, BattleOutcome outcome)
                {
                }

                protected override void OnAfterForeignAttack()
                {
                }

                protected override void OnBeforeForeignCapture(Nation nation, ICity city)
                {
                }

                protected override void OnAfterForeignCapture()
                {
                }
        }
}