import { LatLng, LatLngBounds } from "leaflet";
import { getInfoPopup, getMap, getUnitDataTable } from "..";
import { Unit } from "./unit";
import { cloneUnit } from "../server/server";
import { IDLE, MOVE_UNIT } from "../map/map";
import { keyEventWasInInput } from "../other/utils";

export class UnitsManager {
    #units: { [ID: number]: Unit };
    #copiedUnits: Unit[];
    #selectionEventDisabled: boolean = false;
    #pasteDisabled: boolean = false;

    constructor() {
        this.#units = {};
        this.#copiedUnits = [];

        document.addEventListener('copy', () => this.copyUnits());
        document.addEventListener('paste', () => this.pasteUnits());
        document.addEventListener('unitSelection', (e: CustomEvent) => this.#onUnitSelection(e.detail));
        document.addEventListener('unitDeselection', (e: CustomEvent) => this.#onUnitDeselection(e.detail));
        document.addEventListener('keyup', (event) => this.#onKeyUp(event));
        document.addEventListener('deleteSelectedUnits', () => this.selectedUnitsDelete())
    }

    getSelectableAircraft() {
        const units = this.getUnits();
        return Object.keys(units).reduce((acc: { [key: number]: Unit }, unitId: any) => {
            const baseData = units[unitId].getBaseData();
            if (baseData.category === "Aircraft" && baseData.alive === true) {
                acc[unitId] = units[unitId];
            }
            return acc;
        }, {});
    }

    getUnits() {
        return this.#units;
    }

    getUnitByID(ID: number) {
        if (ID in this.#units)
            return this.#units[ID];
        else
            return null;
    }

    addUnit(ID: number, data: UnitData) {
        /* The name of the unit category is exactly the same as the constructor name */
        var constructor = Unit.getConstructor(data.baseData.category);
        if (constructor != undefined) {
            this.#units[ID] = new constructor(ID, data);
        }
    }

    removeUnit(ID: number) {

    }

    update(data: UnitsData) {
        Object.keys(data.units)
            .filter((ID: string) => !(ID in this.#units))
            .reduce((timeout: number, ID: string) => {
                window.setTimeout(() => {
                    if (!(ID in this.#units))
                        this.addUnit(parseInt(ID), data.units[ID]);
                    this.#units[parseInt(ID)]?.setData(data.units[ID]);
                }, timeout);
                return timeout + 10;
            }, 10);

        Object.keys(data.units)
            .filter((ID: string) => ID in this.#units)
            .forEach((ID: string) => this.#units[parseInt(ID)]?.setData(data.units[ID]));
    }

    selectUnit(ID: number, deselectAllUnits: boolean = true) {
        if (deselectAllUnits)
            this.getSelectedUnits().filter((unit: Unit) => unit.ID !== ID).forEach((unit: Unit) => unit.setSelected(false));
        this.#units[ID]?.setSelected(true);
    }

    selectFromBounds(bounds: LatLngBounds) {
        this.deselectAllUnits();
        for (let ID in this.#units) {
            if (this.#units[ID].getHidden() == false) {
                var latlng = new LatLng(this.#units[ID].getFlightData().latitude, this.#units[ID].getFlightData().longitude);
                if (bounds.contains(latlng)) {
                    this.#units[ID].setSelected(true);
                }
            }
        }
    }

    getSelectedUnits(options?: {excludeHumans?: boolean}) {
        var selectedUnits = [];
        for (let ID in this.#units) {
            if (this.#units[ID].getSelected()) {
                selectedUnits.push(this.#units[ID]);
            }
        }
        if (options) {
            if (options.excludeHumans)
                selectedUnits = selectedUnits.filter((unit: Unit) => {return !unit.getMissionData().flags.Human});
        }
        return selectedUnits;
    }

    deselectAllUnits() {
        for (let ID in this.#units) {
            this.#units[ID].setSelected(false);
        }
    }

    getSelectedUnitsType() {
        if (this.getSelectedUnits().length == 0)
            return undefined;
        return this.getSelectedUnits().map((unit: Unit) => {
            return unit.constructor.name
        })?.reduce((a: any, b: any) => {
            return a == b ? a : undefined
        });
    };

    getSelectedUnitsTargetSpeed() {
        if (this.getSelectedUnits().length == 0)
            return undefined;
        return this.getSelectedUnits().map((unit: Unit) => {
            return unit.getTaskData().targetSpeed
        })?.reduce((a: any, b: any) => {
            return a == b ? a : undefined
        });
    };

    getSelectedUnitsTargetAltitude() {
        if (this.getSelectedUnits().length == 0)
            return undefined;
        return this.getSelectedUnits().map((unit: Unit) => {
            return unit.getTaskData().targetAltitude
        })?.reduce((a: any, b: any) => {
            return a == b ? a : undefined
        });
    };

    getSelectedUnitsCoalition() {
        if (this.getSelectedUnits().length == 0)
            return undefined;
        return this.getSelectedUnits().map((unit: Unit) => {
            return unit.getMissionData().coalition
        })?.reduce((a: any, b: any) => {
            return a == b ? a : undefined
        });
    };

    /*********************** Actions on selected units ************************/
    selectedUnitsAddDestination(latlng: L.LatLng) {
        var selectedUnits = this.getSelectedUnits({excludeHumans: true});
        for (let idx in selectedUnits) {
            const unit = selectedUnits[idx];
            /* If a unit is following another unit, and that unit is also selected, send the command to the followed unit */
            if (unit.getTaskData().currentState === "Follow") {
                const leader = this.getUnitByID(unit.getFormationData().leaderID)
                if (leader && leader.getSelected())
                    leader.addDestination(latlng);
                else
                    unit.addDestination(latlng);
            }
            else
                unit.addDestination(latlng);
        }
        this.#showActionMessage(selectedUnits, " new destination added");
    }

    selectedUnitsClearDestinations() {
        var selectedUnits = this.getSelectedUnits({excludeHumans: true});
        for (let idx in selectedUnits) {
            const unit = selectedUnits[idx];
            if (unit.getTaskData().currentState === "Follow") {
                const leader = this.getUnitByID(unit.getFormationData().leaderID)
                if (leader && leader.getSelected())
                    leader.clearDestinations();
                else
                    unit.clearDestinations();
            }
            else
                unit.clearDestinations();
        }
    }

    selectedUnitsLandAt(latlng: LatLng) {
        var selectedUnits = this.getSelectedUnits({excludeHumans: true});
        for (let idx in selectedUnits) {
            selectedUnits[idx].landAt(latlng);
        }
        this.#showActionMessage(selectedUnits, " landing");
    }

    selectedUnitsChangeSpeed(speedChange: string) {
        var selectedUnits = this.getSelectedUnits({excludeHumans: true});
        for (let idx in selectedUnits) {
            selectedUnits[idx].changeSpeed(speedChange);
        }
    }

    selectedUnitsChangeAltitude(altitudeChange: string) {
        var selectedUnits = this.getSelectedUnits({excludeHumans: true});
        for (let idx in selectedUnits) {
            selectedUnits[idx].changeAltitude(altitudeChange);
        }
    }

    selectedUnitsSetSpeed(speed: number) {
        var selectedUnits = this.getSelectedUnits({excludeHumans: true});
        for (let idx in selectedUnits) {
            selectedUnits[idx].setSpeed(speed);
        }

        this.#showActionMessage(selectedUnits, `setting speed to ${speed * 1.94384} kts`);
    }

    selectedUnitsSetAltitude(altitude: number) {
        var selectedUnits = this.getSelectedUnits({excludeHumans: true});
        for (let idx in selectedUnits) {
            selectedUnits[idx].setAltitude(altitude);
        }
        this.#showActionMessage(selectedUnits, `setting altitude to ${altitude / 0.3048} ft`);
    }

    selectedUnitsSetROE(ROE: string) {
        var selectedUnits = this.getSelectedUnits({excludeHumans: true});
        for (let idx in selectedUnits) {
            selectedUnits[idx].setROE(ROE);
        }
        this.#showActionMessage(selectedUnits, `ROE set to ${ROE}`);
    }

    selectedUnitsSetReactionToThreat(reactionToThreat: string) {
        var selectedUnits = this.getSelectedUnits({excludeHumans: true});
        for (let idx in selectedUnits) {
            selectedUnits[idx].setReactionToThreat(reactionToThreat);
        }
        this.#showActionMessage(selectedUnits, `reaction to threat set to ${reactionToThreat}`);
    }

    selectedUnitsAttackUnit(ID: number) {
        var selectedUnits = this.getSelectedUnits({excludeHumans: true});
        for (let idx in selectedUnits) {
            selectedUnits[idx].attackUnit(ID);
        }
        this.#showActionMessage(selectedUnits, `attacking unit ${this.getUnitByID(ID)?.getBaseData().unitName}`);
    }

    selectedUnitsDelete() {
        var selectedUnits = this.getSelectedUnits(); /* Can be applied to humans too */
        for (let idx in selectedUnits) {
            selectedUnits[idx].delete();
        }
        this.#showActionMessage(selectedUnits, `deleted`);
    }

    selectedUnitsRefuel() {
         var selectedUnits = this.getSelectedUnits({excludeHumans: true});
        for (let idx in selectedUnits) {
            selectedUnits[idx].refuel();
        }
        this.#showActionMessage(selectedUnits, `sent to nearest tanker`);
    }

    selectedUnitsFollowUnit(ID: number, offset?: { "x": number, "y": number, "z": number }, formation?: string) {
        if (offset == undefined) {
            /* Simple formations with fixed offsets */
            // X: front-rear, positive front
            // Y: top-bottom, positive top
            // Z: left-right, positive right
            offset = { "x": 0, "y": 0, "z": 0 };
            if (formation === "Trail") { offset.x = -50; offset.y = -30; offset.z = 0; }
            else if (formation === "Echelon (LH)") { offset.x = -50; offset.y = -10; offset.z = -50; }
            else if (formation === "Echelon (RH)") { offset.x = -50; offset.y = -10; offset.z = 50; }
            else if (formation === "Line abreast (RH)") { offset.x = 0; offset.y = 0; offset.z = 50; }
            else if (formation === "Line abreast (LH)") { offset.x = 0; offset.y = 0; offset.z = -50; }
            else if (formation === "Front") { offset.x = 100; offset.y = 0; offset.z = 0; }
            else offset = undefined;
        }
         var selectedUnits = this.getSelectedUnits({excludeHumans: true});
        var count = 1;
        var xr = 0; var yr = 1; var zr = -1;
        var layer = 1;
        for (let idx in selectedUnits) {
            var unit = selectedUnits[idx];
            if (offset != undefined)
                /* Offset is set, apply it */
                unit.followUnit(ID, { "x": offset.x * count, "y": offset.y * count, "z": offset.z * count });
            else {
                /* More complex formations with variable offsets */
                if (formation === "Diamond") {
                    var xl = xr * Math.cos(Math.PI / 4) - yr * Math.sin(Math.PI / 4);
                    var yl = xr * Math.sin(Math.PI / 4) + yr * Math.cos(Math.PI / 4);
                    unit.followUnit(ID, { "x": -yl * 50, "y": zr * 10, "z": xl * 50 });

                    if (yr == 0) { layer++; xr = 0; yr = layer; zr = -layer; }
                    else {
                        if (xr < layer) { xr++; zr--; }
                        else { yr--; zr++; }
                    }
                }
            }
            count++;
        }
        this.#showActionMessage(selectedUnits, `following unit ${this.getUnitByID(ID)?.getBaseData().unitName}`);
    }

    /***********************************************/
    copyUnits() {
        this.#copiedUnits = this.getSelectedUnits(); /* Can be applied to humans too */
        this.#showActionMessage(this.#copiedUnits, `copied`);
    }

    pasteUnits() {
        if (!this.#pasteDisabled) {
            for (let idx in this.#copiedUnits) {
                var unit = this.#copiedUnits[idx];
                getMap().addTemporaryMarker(getMap().getMouseCoordinates());
                cloneUnit(unit.ID, getMap().getMouseCoordinates());
                this.#showActionMessage(this.#copiedUnits, `pasted`);
            }
            this.#pasteDisabled = true;
            window.setTimeout(() => this.#pasteDisabled = false, 250);
        }
    }

    /***********************************************/
    #onKeyUp(event: KeyboardEvent) {
        if (!keyEventWasInInput(event) && event.key === "Delete" ) {

            const selectedUnits           = this.getSelectedUnits();
            const selectionContainsAHuman = selectedUnits.some( ( unit:Unit ) => {
                return unit.getMissionData().flags.Human === true;
            });

            if ( !selectionContainsAHuman || confirm( "Your selection includes a human player. Deleting humans causes their vehicle to crash.\n\nAre you sure you want to do this?" ) ) {
                this.selectedUnitsDelete();
            }

        }
    }

    #onUnitSelection(unit: Unit) {
        if (this.getSelectedUnits().length > 0) {
            getMap().setState(MOVE_UNIT);
            /* Disable the firing of the selection event for a certain amount of time. This avoids firing many events if many units are selected */
            if (!this.#selectionEventDisabled) {
                window.setTimeout(() => {
                    document.dispatchEvent(new CustomEvent("unitsSelection", { detail: this.getSelectedUnits() }));
                    this.#selectionEventDisabled = false;
                }, 100);
                this.#selectionEventDisabled = true;
            }
        }
        else {
            getMap().setState(IDLE);
            document.dispatchEvent(new CustomEvent("clearSelection"));
        }
    }

    #onUnitDeselection(unit: Unit) {
        if (this.getSelectedUnits().length == 0) {
            getMap().setState(IDLE);
            document.dispatchEvent(new CustomEvent("clearSelection"));
        }
        else
            document.dispatchEvent(new CustomEvent("unitsDeselection", { detail: this.getSelectedUnits() }));
    }

    #showActionMessage(units: Unit[], message: string) {
        if (units.length == 1)
            getInfoPopup().setText(`${units[0].getBaseData().unitName} ${message}`);
        else if (units.length > 1)
            getInfoPopup().setText(`${units[0].getBaseData().unitName} and ${units.length - 1} other units ${message}`);
    }
}