package emu.grasscutter.command.commands;

import emu.grasscutter.GameConstants;
import emu.grasscutter.command.Command;
import emu.grasscutter.command.CommandHandler;
import emu.grasscutter.data.GameData;
import emu.grasscutter.data.GameDepot;
import emu.grasscutter.data.excels.AvatarData;
import emu.grasscutter.data.excels.ItemData;
import emu.grasscutter.data.excels.ReliquaryAffixData;
import emu.grasscutter.data.excels.ReliquaryMainPropData;
import emu.grasscutter.game.avatar.Avatar;
import emu.grasscutter.game.inventory.GameItem;
import emu.grasscutter.game.inventory.ItemType;
import emu.grasscutter.game.player.Player;
import emu.grasscutter.game.props.ActionReason;
import emu.grasscutter.game.props.FightProperty;
import emu.grasscutter.utils.SparseSet;

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

import java.util.regex.Matcher;
import java.util.regex.Pattern;

@Command(
    label = "give",
    aliases = {"g", "item", "giveitem"},
    usage = {
        "(<itemId>|<avatarId>|all|weapons|mats|avatars) [lv<level>] [r<refinement>] [x<amount>] [c<constellation>]",
        "<artifactId> [lv<level>] [x<amount>] [<mainPropId>] [<appendPropId>[,<times>]]..."},
    permission = "player.give",
    permissionTargeted = "player.give.others",
    threading = true)
public final class GiveCommand implements CommandHandler {
    private static Pattern lvlRegex = Pattern.compile("l(?:vl?)?(\\d+)");  // Java doesn't have raw string literals :(
    private static Pattern refineRegex = Pattern.compile("r(\\d+)");
    private static Pattern constellationRegex = Pattern.compile("c(\\d+)");
    private static Pattern amountRegex = Pattern.compile("((?<=x)\\d+|\\d+(?=x)(?!x\\d))");

    private static int matchIntOrNeg(Pattern pattern, String arg) {
        Matcher match = pattern.matcher(arg);
        if (match.find()) {
            return Integer.parseInt(match.group(1));  // This should be exception-safe as only \d+ can be passed to it (i.e. non-empty string of pure digits)
        }
        return -1;
    }

    private static enum GiveAllType {
        NONE,
        ALL,
        WEAPONS,
        MATS,
        AVATARS
    }

    private static class GiveItemParameters {
        public int id;
        public int lvl = 0;
        public int amount = 1;
        public int refinement = 1;
        public int constellation = -1;
        public int mainPropId = -1;
        public List<Integer> appendPropIdList;
        public ItemData data;
        public AvatarData avatarData;
        public GiveAllType giveAllType = GiveAllType.NONE;
    };

    private GiveItemParameters parseArgs(Player sender, List<String> args) throws IllegalArgumentException {
        GiveItemParameters param = new GiveItemParameters();

        // Extract any tagged arguments (e.g. "lv90", "x100", "r5")
        for (int i = args.size() - 1; i >= 0; i--) {  // Reverse iteration as we are deleting elements
            String arg = args.get(i).toLowerCase();
            boolean deleteArg = false;
            int argNum;
            // Note that a single argument can actually match all of these, e.g. "lv90r5x100"
            if ((argNum = matchIntOrNeg(lvlRegex, arg)) != -1) {
                param.lvl = argNum;
                deleteArg = true;
            }
            if ((argNum = matchIntOrNeg(refineRegex, arg)) != -1) {
                param.refinement = argNum;
                deleteArg = true;
            }
            if ((argNum = matchIntOrNeg(constellationRegex, arg)) != -1) {
                param.constellation = argNum;
                deleteArg = true;
            }
            if ((argNum = matchIntOrNeg(amountRegex, arg)) != -1) {
                param.amount = argNum;
                deleteArg = true;
            }
            if (deleteArg) {
                args.remove(i);
            }
        }

        // At this point, first remaining argument MUST be itemId/avatarId
        if (args.size() < 1) {
            sendUsageMessage(sender);  // Reachable if someone does `/give lv90` or similar
            throw new IllegalArgumentException();
        }
        String id = args.remove(0);
        boolean isRelic = false;

        switch (id) {
            case "all":
                param.giveAllType = GiveAllType.ALL;
                break;
            case "weapons":
                param.giveAllType = GiveAllType.WEAPONS;
                break;
            case "mats":
                param.giveAllType = GiveAllType.MATS;
                break;
            case "avatars":
                param.giveAllType = GiveAllType.AVATARS;
                break;
            default:
                try {
                    param.id = Integer.parseInt(id);
                } catch (NumberFormatException e) {
                    // TODO: Parse from item name using GM Handbook.
                    CommandHandler.sendTranslatedMessage(sender, "commands.generic.invalid.itemId");
                    throw e;
                }
                param.data = GameData.getItemDataMap().get(param.id);
                if ((param.id > 10_000_000) && (param.id < 12_000_000))
                    param.avatarData = GameData.getAvatarDataMap().get(param.id);
                else if ((param.id > 1000) && (param.id < 1100))
                    param.avatarData = GameData.getAvatarDataMap().get(param.id - 1000 + 10_000_000);
                isRelic = ((param.data != null) && (param.data.getItemType() == ItemType.ITEM_RELIQUARY));

                if (!isRelic && !args.isEmpty() && (param.amount == 1)) {  // A concession for the people that truly hate [x<amount>].
                    try {
                        param.amount = Integer.parseInt(args.remove(0));
                    } catch (NumberFormatException e) {
                        CommandHandler.sendTranslatedMessage(sender, "commands.generic.invalid.amount");
                        throw e;
                    }
                }
        }

        if (param.amount < 1) param.amount = 1;
        if (param.refinement < 1) param.refinement = 1;
        if (param.refinement > 5) param.refinement = 5;
        if (isRelic) {
            // Input 0-20 to match game, instead of 1-21 which is the real level
            if (param.lvl < 0) param.lvl = 0;
            if (param.lvl > 20) param.lvl = 20;
            param.lvl += 1;
            if (illegalRelicIds.contains(param.id))
                CommandHandler.sendTranslatedMessage(sender, "commands.give.illegal_relic");
        } else {
            // Suitable for Avatars and Weapons
            if (param.lvl < 1) param.lvl = 1;
            if (param.lvl > 90) param.lvl = 90;
        }

        if (!args.isEmpty()) {
            if (isRelic) {
                try {
                    parseRelicArgs(param, args);
                } catch (IllegalArgumentException e) {
                    CommandHandler.sendTranslatedMessage(sender, "commands.execution.argument_error");
                    CommandHandler.sendTranslatedMessage(sender, "commands.give.usage_relic");
                    throw e;
                }
            } else {
                sendUsageMessage(sender);
                throw new IllegalArgumentException();
            }
        }

        return param;
    }

    @Override
    public void execute(Player sender, Player targetPlayer, List<String> args) {
        if (args.size() < 1) { // *No args*
            sendUsageMessage(sender);
            return;
        }
        try {
            GiveItemParameters param = parseArgs(sender, args);

            switch (param.giveAllType) {
                case ALL:
                    giveAll(targetPlayer, param);
                    CommandHandler.sendTranslatedMessage(sender, "commands.give.giveall_success");
                    return;
                case WEAPONS:
                    giveAllWeapons(targetPlayer, param);
                    CommandHandler.sendTranslatedMessage(sender, "commands.give.giveall_success");
                    return;
                case MATS:
                    giveAllMats(targetPlayer, param);
                    CommandHandler.sendTranslatedMessage(sender, "commands.give.giveall_success");
                    return;
                case AVATARS:
                    giveAllAvatars(targetPlayer, param);
                    CommandHandler.sendTranslatedMessage(sender, "commands.give.giveall_success");
                    return;
                case NONE:
                    break;
            }

            // Check if this is an avatar
            if (param.avatarData != null) {
                Avatar avatar = makeAvatar(param);
                targetPlayer.addAvatar(avatar);
                CommandHandler.sendTranslatedMessage(sender, "commands.give.given_avatar", Integer.toString(param.id), Integer.toString(param.lvl), Integer.toString(targetPlayer.getUid()));
                return;
            }
            // If it's not an avatar, it needs to be a valid item
            if (param.data == null) {
                CommandHandler.sendTranslatedMessage(sender, "commands.generic.invalid.itemId");
                return;
            }

            switch (param.data.getItemType()) {
                case ITEM_WEAPON:
                    targetPlayer.getInventory().addItems(makeUnstackableItems(param), ActionReason.SubfieldDrop);
                    CommandHandler.sendTranslatedMessage(sender, "commands.give.given_with_level_and_refinement", Integer.toString(param.id), Integer.toString(param.lvl), Integer.toString(param.refinement), Integer.toString(param.amount), Integer.toString(targetPlayer.getUid()));
                    return;
                case ITEM_RELIQUARY:
                    targetPlayer.getInventory().addItems(makeArtifacts(param), ActionReason.SubfieldDrop);
                    CommandHandler.sendTranslatedMessage(sender, "commands.give.given_level", Integer.toString(param.id), Integer.toString(param.lvl), Integer.toString(param.amount), Integer.toString(targetPlayer.getUid()));
                    return;
                default:
                    targetPlayer.getInventory().addItem(new GameItem(param.data, param.amount), ActionReason.SubfieldDrop);
                    CommandHandler.sendTranslatedMessage(sender, "commands.give.given", Integer.toString(param.amount), Integer.toString(param.id), Integer.toString(targetPlayer.getUid()));
                    return;
            }
        } catch (IllegalArgumentException ignored) {
                return;
        }
    }

    private static Avatar makeAvatar(GiveItemParameters param) {
        return makeAvatar(param.avatarData, param.lvl, Avatar.getMinPromoteLevel(param.lvl), 0);
    }

    private static Avatar makeAvatar(AvatarData avatarData, int level, int promoteLevel, int constellation) {
        // Calculate ascension level.
        Avatar avatar = new Avatar(avatarData);
        avatar.setLevel(level);
        avatar.setPromoteLevel(promoteLevel);

        // Add constellations.
        int talentBase = switch (avatar.getAvatarId()) {
            case 10000005 -> 70;
            case 10000006 -> 40;
            default -> (avatar.getAvatarId() - 10000000) * 10;
        };

        for (int i = 1; i <= constellation; i++) {
            avatar.getTalentIdList().add(talentBase + i);
        }

        // Main character needs skill depot manually added.
        if (avatar.getAvatarId() == GameConstants.MAIN_CHARACTER_MALE) {
            avatar.setSkillDepotData(GameData.getAvatarSkillDepotDataMap().get(504));
        }
        else if (avatar.getAvatarId() == GameConstants.MAIN_CHARACTER_FEMALE) {
            avatar.setSkillDepotData(GameData.getAvatarSkillDepotDataMap().get(704));
        }

        avatar.recalcStats();

        return avatar;
    }

    private static void giveAllAvatars(Player player, GiveItemParameters param) {
        int promoteLevel = Avatar.getMinPromoteLevel(param.lvl);
        if (param.constellation < 0) {
            param.constellation = 6;
        }
        for (AvatarData avatarData : GameData.getAvatarDataMap().values()) {
            // Exclude test avatars
            int id = avatarData.getId();
            if (id < 10000002 || id >= 11000000) continue;

            // Don't try to add each avatar to the current team
            player.addAvatar(makeAvatar(avatarData, param.lvl, promoteLevel, param.constellation), false);
        }
    }

    private static List<GameItem> makeUnstackableItems(GiveItemParameters param) {
        int promoteLevel = GameItem.getMinPromoteLevel(param.lvl);
        int totalExp = 0;
        if (param.data.getItemType() == ItemType.ITEM_WEAPON) {
            int rankLevel = param.data.getRankLevel();
            for (int i = 1; i < param.lvl; i++)
                totalExp += GameData.getWeaponExpRequired(rankLevel, i);
        }

        List<GameItem> items = new ArrayList<>(param.amount);
        for (int i = 0; i < param.amount; i++) {
            GameItem item = new GameItem(param.data);
            item.setLevel(param.lvl);
            if (item.getItemType() == ItemType.ITEM_WEAPON) {
                item.setPromoteLevel(promoteLevel);
                item.setTotalExp(totalExp);
                item.setRefinement(param.refinement - 1);  // Actual refinement data is 0..4 not 1..5
            }
            items.add(item);
        }
        return items;
    }

    private static List<GameItem> makeArtifacts(GiveItemParameters param) {
        param.lvl = Math.min(param.lvl, param.data.getMaxLevel());
        int rank = param.data.getRankLevel();
        int totalExp = 0;
        for (int i = 1; i < param.lvl; i++)
            totalExp += GameData.getRelicExpRequired(rank, i);

        List<GameItem> items = new ArrayList<>(param.amount);
        for (int i = 0; i < param.amount; i++) {
            // Create item for the artifact.
            GameItem item = new GameItem(param.data);
            item.setLevel(param.lvl);
            item.setTotalExp(totalExp);
            int numAffixes = param.data.getAppendPropNum() + (param.lvl-1)/4;
            if (param.mainPropId > 0)  // Keep random mainProp if we didn't specify one
                item.setMainPropId(param.mainPropId);
            if (param.appendPropIdList != null) {
                item.getAppendPropIdList().clear();
                item.getAppendPropIdList().addAll(param.appendPropIdList);
            }
            // If we didn't include enough substats, top them up to the appropriate level at random
            item.addAppendProps(numAffixes - item.getAppendPropIdList().size());
            items.add(item);
        }
        return items;
    }

    private static int getArtifactMainProp(ItemData itemData, FightProperty prop) throws IllegalArgumentException {
        if (prop != FightProperty.FIGHT_PROP_NONE)
            for (ReliquaryMainPropData data : GameDepot.getRelicMainPropList(itemData.getMainPropDepotId()))
                if (data.getWeight() > 0 && data.getFightProp() == prop)
                    return data.getId();
        throw new IllegalArgumentException();
    }

    private static List<Integer> getArtifactAffixes(ItemData itemData, FightProperty prop) throws IllegalArgumentException {
        if (prop == FightProperty.FIGHT_PROP_NONE) {
            throw new IllegalArgumentException();
        }
        List<Integer> affixes = new ArrayList<>();
        for (ReliquaryAffixData data : GameDepot.getRelicAffixList(itemData.getAppendPropDepotId())) {
            if (data.getWeight() > 0 && data.getFightProp() == prop) {
                affixes.add(data.getId());
            }
        }
        return affixes;
    }

    private static int getAppendPropId(String substatText, ItemData itemData) throws IllegalArgumentException {
        // If the given substat text is an integer, we just use that as the append prop ID.
        try {
            return Integer.parseInt(substatText);
        } catch (NumberFormatException ignored) {
            // If the argument was not an integer, we try to determine
            // the append prop ID from the given text + artifact information.
            // A substat string has the format `substat_tier`, with the
            // `_tier` part being optional, defaulting to the maximum.
            String[] substatArgs = substatText.split("_");
            String substatType = substatArgs[0];

            int substatTier = 4;
            if (substatArgs.length > 1) {
                substatTier = Integer.parseInt(substatArgs[1]);
            }

            List<Integer> substats = getArtifactAffixes(itemData, FightProperty.getPropByShortName(substatType));

            if (substats.isEmpty()) {
                throw new IllegalArgumentException();
            }

            substatTier -= 1;  // 1-indexed to 0-indexed
            substatTier = Math.min(Math.max(0, substatTier), substats.size() - 1);
            return substats.get(substatTier);
        }
    }

    private static void parseRelicArgs(GiveItemParameters param, List<String> args) throws IllegalArgumentException {
        // Get the main stat from the arguments.
        // If the given argument is an integer, we use that.
        // If not, we check if the argument string is in the main prop map.
        String mainPropIdString = args.remove(0);

        try {
            param.mainPropId = Integer.parseInt(mainPropIdString);
        } catch (NumberFormatException ignored) {
            // This can in turn throw an exception which we don't want to catch here.
            param.mainPropId = getArtifactMainProp(param.data, FightProperty.getPropByShortName(mainPropIdString));
        }

        // Get substats.
        param.appendPropIdList = new ArrayList<>();
        // Every remaining argument is a substat.
        for (String prop : args) {
            // The substat syntax permits specifying a number of rolls for the given
            // substat. Split the string into stat and number if that is the case here.
            String[] arr = prop.split(",");
            prop = arr[0];
            int n = 1;
            if (arr.length > 1) {
                n = Math.min(Integer.parseInt(arr[1]), 200);
            }

            // Determine the substat ID.
            int appendPropId = getAppendPropId(prop, param.data);

            // Add the current substat.
            for (int i = 0; i < n; i++) {
                param.appendPropIdList.add(appendPropId);
            }
        };
    }

    private static void addItemsChunked(Player player, List<GameItem> items, int packetSize) {
        // Send the items in multiple packets
        int lastIdx = items.size() - 1;
        for (int i = 0; i <= lastIdx; i += packetSize) {
            player.getInventory().addItems(items.subList(i, Math.min(i + packetSize, lastIdx)));
        }
    }

    private static void giveAllMats(Player player, GiveItemParameters param) {
        List<GameItem> itemList = new ArrayList<>();
        for (ItemData itemdata : GameData.getItemDataMap().values()) {
            int id = itemdata.getId();
            if (id < 100_000) continue;  // Nothing meaningful below this
            if (illegalItemIds.contains(id)) continue;
            if (itemdata.isEquip()) continue;

            GameItem item = new GameItem(itemdata);
            item.setCount(param.amount);
            itemList.add(item);
        }

        addItemsChunked(player, itemList, 100);
    }

    private static void giveAllWeapons(Player player, GiveItemParameters param) {
        int promoteLevel = GameItem.getMinPromoteLevel(param.lvl);
        int quantity = Math.min(param.amount, 5);
        int refinement = param.refinement - 1;

        List<GameItem> itemList = new ArrayList<>();
        for (ItemData itemdata : GameData.getItemDataMap().values()) {
            int id = itemdata.getId();
            if (id < 11100 || id > 16000) continue;  // All extant weapons are within this range
            if (illegalWeaponIds.contains(id)) continue;
            if (!itemdata.isEquip()) continue;
            if (itemdata.getItemType() != ItemType.ITEM_WEAPON) continue;

            for (int i = 0; i < quantity; i++) {
                GameItem item = new GameItem(itemdata);
                item.setLevel(param.lvl);
                item.setPromoteLevel(promoteLevel);
                item.setRefinement(refinement);
                itemList.add(item);
            }
        }

        addItemsChunked(player, itemList, 100);
    }

    private static void giveAll(Player player, GiveItemParameters param) {
        giveAllAvatars(player, param);
        giveAllMats(player, param);
        giveAllWeapons(player, param);
    }

    private static final SparseSet illegalWeaponIds = new SparseSet("""
        10000-10008, 11411, 11506-11508, 12505, 12506, 12508, 12509,
        13503, 13506, 14411, 14503, 14505, 14508, 15504-15506
        """);

    private static final SparseSet illegalRelicIds = new SparseSet("""
        20001, 23300-23340, 23383-23385, 78310-78554, 99310-99554
        """);

    private static final SparseSet illegalItemIds = new SparseSet("""
        100086, 100087, 100100-101000, 101106-101110, 101306, 101500-104000,
        105001, 105004, 106000-107000, 107011, 108000, 109000-110000,
        115000-130000, 200200-200899, 220050, 220054
        """);
}