import logger from "../logger";

export async function migrate(): Promise<void> {
    await migrateItems();
    await migrateActors();
    await migrateScenes();
    await migrateCompendiums();
}

async function migrateItems() {
    for (const item of game.items?.entities ?? []) {
        try {
            const updateData = getItemUpdateData(item._data);
            if (updateData) {
                logger.info(`Migrating Item entity ${item.name} (${item.id})`);
                await item.update(updateData), { enforceTypes: false };
            }
        } catch (err) {
            err.message = `Error during migration of Item entity ${item.name} (${item.id}), continuing anyways.`;
            logger.error(err);
        }
    }
}

function getItemUpdateData(itemData: DeepPartial<Item.Data>) {
    if (!["loot"].includes(itemData.type ?? "")) return undefined;
    return {
        data: {
            "-=equipped": null,
        },
    };
}

async function migrateActors() {
    for (const actor of game.actors?.entities ?? []) {
        try {
            const updateData = getActorUpdateData(actor._data);
            if (updateData) {
                logger.info(`Migrating Actor entity ${actor.name} (${actor.id})`);
                await actor.update(updateData, { enforceTypes: false });
            }
        } catch (err) {
            err.message = `Error during migration of Actor entity ${actor.name} (${actor.id}), continuing anyways.`;
            logger.error(err);
        }
    }
}

function getActorUpdateData(actorData: DeepPartial<Actor.Data>) {
    let hasItemUpdates = false;
    const items = actorData.items?.map((itemData) => {
        const update = itemData ? getItemUpdateData(itemData) : undefined;
        if (update) {
            hasItemUpdates = true;
            return mergeObject(itemData, update, { enforceTypes: false, inplace: false });
        } else {
            return itemData;
        }
    });
    return hasItemUpdates ? { items } : undefined;
}

async function migrateScenes() {
    for (const scene of game.scenes?.entities ?? []) {
        try {
            const updateData = getSceneUpdateData(scene._data);
            if (updateData) {
                logger.info(`Migrating Scene entity ${scene.name} (${scene.id})`);
                await scene.update(updateData, { enforceTypes: false });
            }
        } catch (err) {
            err.message = `Error during migration of Scene entity ${scene.name} (${scene.id}), continuing anyways.`;
            logger.error(err);
        }
    }
}

function getSceneUpdateData(sceneData: Scene.Data) {
    let hasTokenUpdates = false;
    const tokens = sceneData.tokens.map((tokenData) => {
        if (!tokenData.actorId || tokenData.actorLink || tokenData.actorData.data) {
            tokenData.actorData = {};
            hasTokenUpdates = true;
            return tokenData;
        }
        const token = new Token(tokenData);
        if (!token.actor) {
            tokenData.actorId = null as unknown as string;
            tokenData.actorData = {};
            hasTokenUpdates = true;
        } else if (!tokenData.actorLink) {
            const actorUpdateData = getActorUpdateData(token.data.actorData);
            tokenData.actorData = mergeObject(token.data.actorData, actorUpdateData);
            hasTokenUpdates = true;
        }
        return tokenData;
    });
    if (!hasTokenUpdates) return undefined;
    return hasTokenUpdates ? { tokens } : undefined;
}

async function migrateCompendiums() {
    for (const compendium of game.packs ?? []) {
        if (compendium.metadata.package !== "world") continue;
        if (!["Actor", "Item", "Scene"].includes(compendium.metadata.entity)) continue;
        await migrateCompendium(compendium);
    }
}

async function migrateCompendium(compendium: Compendium) {
    const entityName = compendium.metadata.entity;
    if (!["Actor", "Item", "Scene"].includes(entityName)) return;
    const wasLocked = compendium.locked;
    await compendium.configure({ locked: false });

    const content = await compendium.getContent();

    for (const entity of content) {
        try {
            const getUpdateData = (entity: Entity) => {
                switch (entityName) {
                    case "Item":
                        return getItemUpdateData(entity._data);
                    case "Actor":
                        return getActorUpdateData(entity._data);
                    case "Scene":
                        return getSceneUpdateData(entity._data as Scene.Data);
                }
            };
            const updateData = getUpdateData(entity);
            if (updateData) {
                logger.info(`Migrating entity ${entity.name} (${entity.id}) in compendium ${compendium.collection}`);
                await compendium.updateEntity({ ...updateData, _id: entity._id });
            }
        } catch (err) {
            err.message = `Error during migration of entity ${entity.name} (${entity.id}) in compendium ${compendium.collection}, continuing anyways.`;
            logger.error(err);
        }
    }

    await compendium.migrate({});
    await compendium.configure({ locked: wasLocked });
}