source: ps/trunk/binaries/data/mods/public/simulation/components/ResourceGatherer.js@ 25243

function ResourceGatherer() {}

ResourceGatherer.prototype.Schema =
    "<a:help>Lets the unit gather resources from entities that have the ResourceSupply component.</a:help>" +
    "<a:example>" +
        "<MaxDistance>2.0</MaxDistance>" +
        "<BaseSpeed>1.0</BaseSpeed>" +
        "<Rates>" +
            "<food.fish>1</food.fish>" +
            "<metal.ore>3</metal.ore>" +
            "<stone.rock>3</stone.rock>" +
            "<wood.tree>2</wood.tree>" +
        "</Rates>" +
        "<Capacities>" +
            "<food>10</food>" +
            "<metal>10</metal>" +
            "<stone>10</stone>" +
            "<wood>10</wood>" +
        "</Capacities>" +
    "</a:example>" +
    "<element name='MaxDistance' a:help='Max resource-gathering distance'>" +
        "<ref name='positiveDecimal'/>" +
    "</element>" +
    "<element name='BaseSpeed' a:help='Base resource-gathering rate (in resource units per second)'>" +
        "<ref name='positiveDecimal'/>" +
    "</element>" +
    "<element name='Rates' a:help='Per-resource-type gather rate multipliers. If a resource type is not specified then it cannot be gathered by this unit'>" +
        Resources.BuildSchema("positiveDecimal", [], true) +
    "</element>" +
    "<element name='Capacities' a:help='Per-resource-type maximum carrying capacity'>" +
        Resources.BuildSchema("positiveDecimal") +
    "</element>";

/*
 * Call interval will be determined by gather rate,
 * so always gather integer amount.
 */
ResourceGatherer.prototype.GATHER_AMOUNT = 1;

ResourceGatherer.prototype.Init = function()
{
    this.capacities = {};
    this.carrying = {}; // { generic type: integer amount currently carried }
    // (Note that this component supports carrying multiple types of resources,
    // each with an independent capacity, but the rest of the game currently
    // ensures and assumes we'll only be carrying one type at once)

    // The last exact type gathered, so we can render appropriate props
    this.lastCarriedType = undefined; // { generic, specific }
};

/**
 * Returns data about what resources the unit is currently carrying,
 * in the form [ {"type":"wood", "amount":7, "max":10} ]
 */
ResourceGatherer.prototype.GetCarryingStatus = function()
{
    let ret = [];
    for (let type in this.carrying)
    {
        ret.push({
            "type": type,
            "amount": this.carrying[type],
            "max": +this.GetCapacity(type)
        });
    }
    return ret;
};

/**
 * Used to instantly give resources to unit
 * @param resources The same structure as returned form GetCarryingStatus
 */
ResourceGatherer.prototype.GiveResources = function(resources)
{
    for (let resource of resources)
        this.carrying[resource.type] = +resource.amount;

    Engine.PostMessage(this.entity, MT_ResourceCarryingChanged, { "to": this.GetCarryingStatus() });
};

/**
 * Returns the generic type of one particular resource this unit is
 * currently carrying, or undefined if none.
 */
ResourceGatherer.prototype.GetMainCarryingType = function()
{
    // Return the first key, if any
    for (let type in this.carrying)
        return type;

    return undefined;
};

/**
 * Returns the exact resource type we last picked up, as long as
 * we're still carrying something similar enough, in the form
 * { generic, specific }
 */
ResourceGatherer.prototype.GetLastCarriedType = function()
{
    if (this.lastCarriedType && this.lastCarriedType.generic in this.carrying)
        return this.lastCarriedType;

    return undefined;
};

ResourceGatherer.prototype.SetLastCarriedType = function(lastCarriedType)
{
    this.lastCarriedType = lastCarriedType;
};

// Since this code is very performancecritical and applying technologies quite slow, cache it.
ResourceGatherer.prototype.RecalculateGatherRates = function()
{
    this.baseSpeed = ApplyValueModificationsToEntity("ResourceGatherer/BaseSpeed", +this.template.BaseSpeed, this.entity);

    this.rates = {};
    for (let r in this.template.Rates)
    {
        let type = r.split(".");

        if (!Resources.GetResource(type[0]).subtypes[type[1]])
        {
            error("Resource subtype not found: " + type[0] + "." + type[1]);
            continue;
        }

        let rate = ApplyValueModificationsToEntity("ResourceGatherer/Rates/" + r, +this.template.Rates[r], this.entity);
        this.rates[r] = rate * this.baseSpeed;
    }
};

ResourceGatherer.prototype.RecalculateCapacities = function()
{
    this.capacities = {};
    for (let r in this.template.Capacities)
        this.capacities[r] = ApplyValueModificationsToEntity("ResourceGatherer/Capacities/" + r, +this.template.Capacities[r], this.entity);
};

ResourceGatherer.prototype.RecalculateCapacity = function(type)
{
    if (type in this.capacities)
        this.capacities[type] = ApplyValueModificationsToEntity("ResourceGatherer/Capacities/" + type, +this.template.Capacities[type], this.entity);
};

ResourceGatherer.prototype.GetGatherRates = function()
{
    return this.rates;
};

ResourceGatherer.prototype.GetGatherRate = function(resourceType)
{
    if (!this.template.Rates[resourceType])
        return 0;

    return this.rates[resourceType];
};

ResourceGatherer.prototype.GetCapacity = function(resourceType)
{
    if (!this.template.Capacities[resourceType])
        return 0;
    return this.capacities[resourceType];
};

ResourceGatherer.prototype.GetRange = function()
{
    return { "max": +this.template.MaxDistance, "min": 0 };
};

/**
 * @param {number} target - The target to gather from.
 * @param {number} callerIID - The IID to notify on specific events.
 * @return {boolean} - Whether we started gathering.
 */
ResourceGatherer.prototype.StartGathering = function(target, callerIID)
{
    if (this.target)
        this.StopGathering();

    let rate = this.GetTargetGatherRate(target);
    if (!rate)
        return false;

    let cmpResourceSupply = Engine.QueryInterface(target, IID_ResourceSupply);
    if (!cmpResourceSupply || !cmpResourceSupply.AddActiveGatherer(this.entity))
        return false;

    let resourceType = cmpResourceSupply.GetType();

    // If we've already got some resources but they're the wrong type,
    // drop them first to ensure we're only ever carrying one type.
    if (this.IsCarryingAnythingExcept(resourceType.generic))
        this.DropResources();
    this.AddToPlayerCounter(resourceType.generic);

    let cmpVisual = Engine.QueryInterface(this.entity, IID_Visual);
    if (cmpVisual)
        cmpVisual.SelectAnimation("gather_" + resourceType.specific, false, 1.0);

    // Calculate timing based on gather rates.
    // This allows the gather rate to control how often we gather, instead of how much.
    let timing = 1000 / rate;

    this.target = target;
    this.callerIID = callerIID;

    let cmpTimer = Engine.QueryInterface(SYSTEM_ENTITY, IID_Timer);
    this.timer = cmpTimer.SetInterval(this.entity, IID_ResourceGatherer, "PerformGather", timing, timing, null);

    return true;
};

/**
 * @param {string} reason - The reason why we stopped gathering used to notify the caller.
 */
ResourceGatherer.prototype.StopGathering = function(reason)
{
    if (!this.target)
        return;

    let cmpTimer = Engine.QueryInterface(SYSTEM_ENTITY, IID_Timer);
    cmpTimer.CancelTimer(this.timer);
    delete this.timer;

    let cmpResourceSupply = Engine.QueryInterface(this.target, IID_ResourceSupply);
    if (cmpResourceSupply)
        cmpResourceSupply.RemoveGatherer(this.entity);
    this.RemoveFromPlayerCounter();

    delete this.target;

    let cmpVisual = Engine.QueryInterface(this.entity, IID_Visual);
    if (cmpVisual)
        cmpVisual.SelectAnimation("idle", false, 1.0);

    // The callerIID component may start again,
    // replacing the callerIID, hence save that.
    let callerIID = this.callerIID;
    delete this.callerIID;

    if (reason && callerIID)
    {
        let component = Engine.QueryInterface(this.entity, callerIID);
        if (component)
            component.ProcessMessage(reason, null);
    }
};

/**
 * Gather from our target entity.
 * @params - data and lateness are unused.
 */
ResourceGatherer.prototype.PerformGather = function(data, lateness)
{
    let cmpResourceSupply = Engine.QueryInterface(this.target, IID_ResourceSupply);
    if (!cmpResourceSupply || cmpResourceSupply.GetCurrentAmount() <= 0)
    {
        this.StopGathering("TargetInvalidated");
        return;
    }

    if (!this.IsTargetInRange(this.target))
    {
        this.StopGathering("OutOfRange");
        return;
    }

    // ToDo: Enable entities to keep facing a target.
    Engine.QueryInterface(this.entity, IID_UnitAI)?.FaceTowardsTarget(this.target);

    let type = cmpResourceSupply.GetType();
    if (!this.carrying[type.generic])
        this.carrying[type.generic] = 0;

    let maxGathered = this.GetCapacity(type.generic) - this.carrying[type.generic];
    let status = cmpResourceSupply.TakeResources(Math.min(this.GATHER_AMOUNT, maxGathered));
    this.carrying[type.generic] += status.amount;
    this.lastCarriedType = type;

    // Update stats of how much the player collected.
    // (We have to do it here rather than at the dropsite, because we
    // need to know what subtype it was.)
    let cmpStatisticsTracker = QueryOwnerInterface(this.entity, IID_StatisticsTracker);
    if (cmpStatisticsTracker)
        cmpStatisticsTracker.IncreaseResourceGatheredCounter(type.generic, status.amount, type.specific);

    Engine.PostMessage(this.entity, MT_ResourceCarryingChanged, { "to": this.GetCarryingStatus() });

    if (!this.CanCarryMore(type.generic))
        this.StopGathering("InventoryFilled");
    else if (status.exhausted)
        this.StopGathering("TargetInvalidated");
};

/**
 * Compute the amount of resources collected per second from the target.
 * Returns 0 if resources cannot be collected (e.g. the target doesn't
 * exist, or is the wrong type).
 */
ResourceGatherer.prototype.GetTargetGatherRate = function(target)
{
    let cmpResourceSupply = QueryMiragedInterface(target, IID_ResourceSupply);
    if (!cmpResourceSupply || cmpResourceSupply.GetCurrentAmount() <= 0)
        return 0;

    let type = cmpResourceSupply.GetType();

    let rate = 0;
    if (type.specific)
        rate = this.GetGatherRate(type.generic + "." + type.specific);
    if (rate == 0 && type.generic)
        rate = this.GetGatherRate(type.generic);

    let diminishingReturns = cmpResourceSupply.GetDiminishingReturns();
    if (diminishingReturns)
        rate *= diminishingReturns;

    return rate;
};

/**
 * @param {number} target - The entity ID of the target to check.
 * @return {boolean} - Whether we can gather from the target.
 */
ResourceGatherer.prototype.CanGather = function(target)
{
    return this.GetTargetGatherRate(target) > 0;
};

/**
 * Returns whether this unit can carry more of the given type of resource.
 * (This ignores whether the unit is actually able to gather that
 * resource type or not.)
 */
ResourceGatherer.prototype.CanCarryMore = function(type)
{
    let amount = this.carrying[type] || 0;
    return amount < this.GetCapacity(type);
};


ResourceGatherer.prototype.IsCarrying = function(type)
{
    let amount = this.carrying[type] || 0;
    return amount > 0;
};

/**
 * Returns whether this unit is carrying any resources of a type that is
 * not the requested type. (This is to support cases where the unit is
 * only meant to be able to carry one type at once.)
 */
ResourceGatherer.prototype.IsCarryingAnythingExcept = function(exceptedType)
{
    for (let type in this.carrying)
        if (type != exceptedType)
            return true;

    return false;
};

/**
 * @param {number} target - The entity to check.
 * @param {boolean} checkCarriedResource - Whether we need to check the resource we are carrying.
 * @return {boolean} - Whether we can return carried resources.
 */
ResourceGatherer.prototype.CanReturnResource = function(target, checkCarriedResource)
{
    let cmpResourceDropsite = Engine.QueryInterface(target, IID_ResourceDropsite);
    if (!cmpResourceDropsite)
        return false;

    if (checkCarriedResource)
    {
        let type = this.GetMainCarryingType();
        if (!type || !cmpResourceDropsite.AcceptsType(type))
            return false;
    }

    let cmpOwnership = Engine.QueryInterface(this.entity, IID_Ownership);
    if (cmpOwnership && IsOwnedByPlayer(cmpOwnership.GetOwner(), target))
        return true;
    let cmpPlayer = QueryOwnerInterface(this.entity);
    return cmpPlayer && cmpPlayer.HasSharedDropsites() && cmpResourceDropsite.IsShared() &&
           cmpOwnership && IsOwnedByMutualAllyOfPlayer(cmpOwnership.GetOwner(), target);
};

/**
 * Transfer our carried resources to our owner immediately.
 * Only resources of the appropriate types will be transferred.
 * (This should typically be called after reaching a dropsite.)
 *
 * @param {number} target - The target entity ID to drop resources at.
 */
ResourceGatherer.prototype.CommitResources = function(target)
{
    let cmpResourceDropsite = Engine.QueryInterface(target, IID_ResourceDropsite);
    if (!cmpResourceDropsite)
        return;

    let change = cmpResourceDropsite.ReceiveResources(this.carrying, this.entity);
    let changed = false;
    for (let type in change)
    {
        this.carrying[type] -= change[type];
        if (this.carrying[type] == 0)
            delete this.carrying[type];
        changed = true;
    }

    if (changed)
        Engine.PostMessage(this.entity, MT_ResourceCarryingChanged, { "to": this.GetCarryingStatus() });
};

/**
 * Drop all currently-carried resources.
 * (Currently they just vanish after being dropped - we don't bother depositing
 * them onto the ground.)
 */
ResourceGatherer.prototype.DropResources = function()
{
    this.carrying = {};

    Engine.PostMessage(this.entity, MT_ResourceCarryingChanged, { "to": this.GetCarryingStatus() });
};


/**
 * @param {string} type - A generic resource type.
 */
ResourceGatherer.prototype.AddToPlayerCounter = function(type)
{
    // We need to be removed from the player counter first.
    if (this.lastGathered)
        return;

    let cmpPlayer = QueryOwnerInterface(this.entity, IID_Player);
    if (cmpPlayer)
        cmpPlayer.AddResourceGatherer(type);

    this.lastGathered = type;
};

/**
 * @param {number} playerid - Optionally a player ID.
 */
ResourceGatherer.prototype.RemoveFromPlayerCounter = function(playerid)
{
    if (!this.lastGathered)
        return;

    let cmpPlayer = playerid != undefined ?
        QueryPlayerIDInterface(playerid) :
        QueryOwnerInterface(this.entity, IID_Player);

    if (cmpPlayer)
        cmpPlayer.RemoveResourceGatherer(this.lastGathered);

    delete this.lastGathered;
};

/**
 * @param {number} - The entity ID of the target to check.
 * @return {boolean} - Whether this entity is in range of its target.
 */
ResourceGatherer.prototype.IsTargetInRange = function(target)
{
    return Engine.QueryInterface(SYSTEM_ENTITY, IID_ObstructionManager).
        IsInTargetRange(this.entity, target, 0, +this.template.MaxDistance, false);
};

// Since we cache gather rates, we need to make sure we update them when tech changes.
// and when our owner change because owners can had different techs.
ResourceGatherer.prototype.OnValueModification = function(msg)
{
    if (msg.component != "ResourceGatherer")
        return;

    // NB: at the moment, 0 A.D. always uses the fast path, the other is mod support.
    if (msg.valueNames.length === 1)
    {
        if (msg.valueNames[0].indexOf("Capacities") !== -1)
            this.RecalculateCapacity(msg.valueNames[0].substr(28));
        else
            this.RecalculateGatherRates();
    }
    else
    {
        this.RecalculateGatherRates();
        this.RecalculateCapacities();
    }
};

ResourceGatherer.prototype.OnOwnershipChanged = function(msg)
{
    if (msg.to == INVALID_PLAYER)
    {
        this.RemoveFromPlayerCounter(msg.from);
        return;
    }

    this.RecalculateGatherRates();
    this.RecalculateCapacities();
};

ResourceGatherer.prototype.OnGlobalInitGame = function(msg)
{
    this.RecalculateGatherRates();
    this.RecalculateCapacities();
};

ResourceGatherer.prototype.OnMultiplierChanged = function(msg)
{
    let cmpPlayer = QueryOwnerInterface(this.entity, IID_Player);
    if (cmpPlayer && msg.player == cmpPlayer.GetPlayerID())
        this.RecalculateGatherRates();
};

Engine.RegisterComponentType(IID_ResourceGatherer, "ResourceGatherer", ResourceGatherer);