import {
    CSSProperties,
    Dispatch,
    RefObject,
    SetStateAction,
    useCallback,
    useEffect,
    useMemo,
    useRef,
    useState,
} from "react"
import "../style/editor.css"
import TitleInput from "../components/TitleInput"
import PlainCourt from "../assets/court/full_court.svg?react"
import HalfCourt from "../assets/court/half_court.svg?react"

import {BallPiece} from "../components/editor/BallPiece"

import {Rack} from "../components/Rack"
import {PlayerPiece} from "../components/editor/PlayerPiece"

import {Tactic, TacticComponent, TacticContent} from "../model/tactic/Tactic"
import {fetchAPI} from "../Fetcher"

import SavingState, {SaveState, SaveStates,} from "../components/editor/SavingState"

import {BALL_TYPE} from "../model/tactic/CourtObjects"
import {CourtAction} from "./editor/CourtAction"
import {ActionPreview, BasketCourt} from "../components/editor/BasketCourt"
import {overlaps} from "../geo/Box"
import {
    dropBallOnComponent,
    getComponentCollided,
    getRackPlayers,
    moveComponent,
    placeBallAt,
    placeObjectAt,
    placePlayerAt,
    removeBall,
    updateComponent,
} from "../editor/TacticContentDomains"
import {BallState, Player, PlayerInfo, PlayerPhantom, PlayerTeam,} from "../model/tactic/Player"
import {RackedCourtObject, RackedPlayer} from "../editor/RackedItems"
import CourtPlayer from "../components/editor/CourtPlayer"
import {createAction, getActionKind, isActionValid, removeAction} from "../editor/ActionsDomains"
import ArrowAction from "../components/actions/ArrowAction"
import {middlePos, Pos, ratioWithinBase} from "../geo/Pos"
import {Action, ActionKind} from "../model/tactic/Action"
import BallAction from "../components/actions/BallAction"
import {changePlayerBallState, getOrigin, removePlayer,} from "../editor/PlayerDomains"
import {CourtBall} from "../components/editor/CourtBall"
import {BASE} from "../Constants"

const ERROR_STYLE: CSSProperties = {
    borderColor: "red",
}

const GUEST_MODE_CONTENT_STORAGE_KEY = "guest_mode_content"
const GUEST_MODE_TITLE_STORAGE_KEY = "guest_mode_title"

export interface EditorViewProps {
    tactic: Tactic
    onContentChange: (tactic: TacticContent) => Promise<SaveState>
    onNameChange: (name: string) => Promise<boolean>
    courtType: "PLAIN" | "HALF"
}

export interface EditorProps {
    id: number
    name: string
    content: string
    courtType: "PLAIN" | "HALF"
}

export default function Editor({id, name, courtType, content}: EditorProps) {
    const isInGuestMode = id == -1

    const storage_content = localStorage.getItem(GUEST_MODE_CONTENT_STORAGE_KEY)
    const editorContent =
        isInGuestMode && storage_content != null ? storage_content : content

    const storage_name = localStorage.getItem(GUEST_MODE_TITLE_STORAGE_KEY)
    const editorName =
        isInGuestMode && storage_name != null ? storage_name : name

    return (
        <EditorView
            tactic={{
                name: editorName,
                id,
                content: JSON.parse(editorContent),
            }}
            onContentChange={async (content: TacticContent) => {
                if (isInGuestMode) {
                    localStorage.setItem(
                        GUEST_MODE_CONTENT_STORAGE_KEY,
                        JSON.stringify(content),
                    )
                    return SaveStates.Guest
                }
                return fetchAPI(`tactic/${id}/save`, {content}).then((r) =>
                    r.ok ? SaveStates.Ok : SaveStates.Err,
                )
            }}
            onNameChange={async (name: string) => {
                if (isInGuestMode) {
                    localStorage.setItem(GUEST_MODE_TITLE_STORAGE_KEY, name)
                    return true //simulate that the name has been changed
                }
                return fetchAPI(`tactic/${id}/edit/name`, {name}).then(
                    (r) => r.ok,
                )
            }}
            courtType={courtType}
        />
    )
}

function EditorView({
                        tactic: {id, name, content: initialContent},
                        onContentChange,
                        onNameChange,
                        courtType,
                    }: EditorViewProps) {

    const isInGuestMode = id == -1

    const [titleStyle, setTitleStyle] = useState<CSSProperties>({})
    const [content, setContent, saveState] = useContentState(
        initialContent,
        isInGuestMode ? SaveStates.Guest : SaveStates.Ok,
        useMemo(
            () =>
                debounceAsync(
                    (content) =>
                        onContentChange(content).then((success) =>
                            success ? SaveStates.Ok : SaveStates.Err,
                        ),
                    250,
                ),
            [onContentChange],
        ),
    )

    const [allies, setAllies] = useState(() =>
        getRackPlayers(PlayerTeam.Allies, content.components),
    )
    const [opponents, setOpponents] = useState(() =>
        getRackPlayers(PlayerTeam.Opponents, content.components),
    )

    const [objects, setObjects] = useState<RackedCourtObject[]>(() =>
        isBallOnCourt(content) ? [] : [{key: "ball"}],
    )

    const [previewAction, setPreviewAction] = useState<ActionPreview | null>(
        null,
    )

    const courtRef = useRef<HTMLDivElement>(null)

    const setComponents = (action: SetStateAction<TacticComponent[]>) => {
        setContent((c) => ({
            ...c,
            components:
                typeof action == "function" ? action(c.components) : action,
        }))
    }

    const courtBounds = useCallback(() => courtRef.current!.getBoundingClientRect(), [courtRef])

    useEffect(() => {
        setObjects(isBallOnCourt(content) ? [] : [{key: "ball"}])
    }, [setObjects, content]);

    const insertRackedPlayer = (player: Player) => {
        let setter
        switch (player.team) {
            case PlayerTeam.Opponents:
                setter = setOpponents
                break
            case PlayerTeam.Allies:
                setter = setAllies
        }
        if (player.ballState == BallState.HOLDS_BY_PASS) {
            setObjects([{key: "ball"}])
        }
        setter((players) => [
            ...players,
            {
                team: player.team,
                pos: player.role,
                key: player.role,
            },
        ])
    }

    const doRemovePlayer = useCallback((component: Player | PlayerPhantom) => {
        setContent((c) => removePlayer(component, c))
        if (component.type == "player") insertRackedPlayer(component)
    }, [setContent])

    const doMoveBall = useCallback((newBounds: DOMRect, from?: Player | PlayerPhantom) => {
        setContent((content) => {
            if (from) {
                content = changePlayerBallState(from, BallState.NONE, content)
            }

            content = placeBallAt(
                newBounds,
                courtBounds(),
                content,
            )

            return content
        })
    }, [courtBounds, setContent])

    const validatePlayerPosition = useCallback((player: Player | PlayerPhantom, info: PlayerInfo, newPos: Pos) => {
        setContent((content) =>
            moveComponent(
                newPos,
                player,
                info,
                courtBounds(),
                content,

                (content) => {
                    if (player.type == "player") insertRackedPlayer(player)
                    return removePlayer(player, content)
                },
            ),
        )
    }, [courtBounds, setContent])

    const renderAvailablePlayerActions = useCallback((info: PlayerInfo, player: Player | PlayerPhantom) => {
        let canPlaceArrows: boolean

        if (player.type == "player") {
            canPlaceArrows =
                player.path == null ||
                player.actions.findIndex(
                    (p) => p.type != ActionKind.SHOOT,
                ) == -1
        } else {
            const origin = getOrigin(player, content.components)
            const path = origin.path!
            // phantoms can only place other arrows if they are the head of the path
            canPlaceArrows =
                path.items.indexOf(player.id) == path.items.length - 1
            if (canPlaceArrows) {
                // and if their only action is to shoot the ball
                const phantomActions = player.actions
                canPlaceArrows =
                    phantomActions.length == 0 ||
                    phantomActions.findIndex(
                        (c) => c.type != ActionKind.SHOOT,
                    ) == -1
            }
        }


        return [
            canPlaceArrows && (
                <CourtPlayerArrowAction
                    key={1}
                    player={player}
                    isInvalid={previewAction?.isInvalid ?? false}
                    setPreviewAction={setPreviewAction}
                    playerInfo={info}
                    content={content}
                    courtRef={courtRef}
                    setContent={setContent}
                />
            ),
            (info.ballState === BallState.HOLDS_ORIGIN || info.ballState === BallState.PASSED_ORIGIN) && (
                <BallAction key={2} onDrop={(ballBounds) => {
                    doMoveBall(ballBounds, player)
                }}/>
            ),
        ]
    }, [content, doMoveBall, previewAction?.isInvalid, setContent])

    const renderPlayer = useCallback((component: Player | PlayerPhantom) => {
        let info: PlayerInfo
        const isPhantom = component.type == "phantom"
        if (isPhantom) {
            const origin = getOrigin(component, content.components)
            info = {
                id: component.id,
                team: origin.team,
                role: origin.role,
                bottomRatio: component.bottomRatio,
                rightRatio: component.rightRatio,
                ballState: component.ballState,
            }
        } else {
            info = component
        }

        return (
            <CourtPlayer
                key={component.id}
                className={isPhantom ? "phantom" : "player"}
                playerInfo={info}
                onPositionValidated={(newPos) => validatePlayerPosition(component, info, newPos)}
                onRemove={() => doRemovePlayer(component)}
                courtRef={courtRef}
                availableActions={() => renderAvailablePlayerActions(info, component)}
            />
        )
    }, [content.components, doRemovePlayer, renderAvailablePlayerActions, validatePlayerPosition])

    const doDeleteAction = useCallback((
        action: Action,
        idx: number,
        origin: TacticComponent,
    ) => {
        setContent((content) => removeAction(origin, action, idx, content))
    }, [setContent])

    const doUpdateAction = useCallback((component: TacticComponent, action: Action, actionIndex: number) => {
        setContent((content) =>
            updateComponent(
                {
                    ...component,
                    actions:
                        component.actions.toSpliced(
                            actionIndex,
                            1,
                            action,
                        ),
                },
                content,
            ),
        )
    }, [setContent])

    const renderComponent = useCallback((component: TacticComponent) => {
        if (
            component.type == "player" ||
            component.type == "phantom"
        ) {
            return renderPlayer(component)
        }
        if (component.type == BALL_TYPE) {
            return (
                <CourtBall
                    key="ball"
                    ball={component}
                    onPosValidated={doMoveBall}
                    onRemove={() => {
                        setContent((content) =>
                            removeBall(content),
                        )
                        setObjects((objects) => [
                            ...objects,
                            {key: "ball"},
                        ])
                    }}
                />
            )
        }
        throw new Error(
            "unknown tactic component " + component,
        )
    }, [renderPlayer, doMoveBall, setContent])

    const renderActions = useCallback((component: TacticComponent) =>
        component.actions.map((action, i) => {
            return (
                <CourtAction
                    key={"action-" + component.id + "-" + i}
                    action={action}
                    origin={component.id}
                    courtRef={courtRef}
                    isInvalid={false}
                    onActionDeleted={() => {
                        doDeleteAction(action, i, component)
                    }}
                    onActionChanges={(action) =>
                        doUpdateAction(component, action, i)
                    }
                />
            )
        }), [doDeleteAction, doUpdateAction])

    return (
        <div id="main-div">
            <div id="topbar-div">
                <button onClick={() => (location.pathname = BASE + "/")}>
                    Home
                </button>
                <div id="topbar-left">
                    <SavingState state={saveState}/>
                </div>
                <div id="title-input-div">
                    <TitleInput
                        style={titleStyle}
                        default_value={name}
                        onValidated={useCallback((new_name) => {
                            onNameChange(new_name).then((success) => {
                                setTitleStyle(success ? {} : ERROR_STYLE)
                            })
                        }, [onNameChange])}
                    />
                </div>
                <div id="topbar-right"/>
            </div>
            <div id="edit-div">
                <div id="racks">
                    <PlayerRack id={"allies"} objects={allies} setObjects={setAllies} setComponents={setComponents}
                                courtRef={courtRef}/>

                    <Rack
                        id={"objects"}
                        objects={objects}
                        onChange={setObjects}
                        canDetach={useCallback((div) =>
                                overlaps(courtBounds(), div.getBoundingClientRect())
                            , [courtBounds])}
                        onElementDetached={useCallback((r, e: RackedCourtObject) =>
                                setContent((content) =>
                                    placeObjectAt(
                                        r.getBoundingClientRect(),
                                        courtBounds(),
                                        e,
                                        content,
                                    ),
                                )
                            , [courtBounds, setContent])}
                        render={renderCourtObject}
                    />

                    <PlayerRack id={"opponents"} objects={opponents} setObjects={setOpponents}
                                setComponents={setComponents} courtRef={courtRef}/>
                </div>
                <div id="court-div">
                    <div id="court-div-bounds">
                        <BasketCourt
                            components={content.components}
                            courtImage={<Court courtType={courtType}/>}
                            courtRef={courtRef}
                            previewAction={previewAction}
                            renderComponent={renderComponent}
                            renderActions={renderActions}
                        />
                    </div>
                </div>
            </div>
        </div>
    )
}

interface PlayerRackProps {
    id: string
    objects: RackedPlayer[]
    setObjects: (state: RackedPlayer[]) => void
    setComponents: (f: (components: TacticComponent[]) => TacticComponent[]) => void
    courtRef: RefObject<HTMLDivElement>
}

function PlayerRack({id, objects, setObjects, courtRef, setComponents}: PlayerRackProps) {

    const courtBounds = useCallback(() => courtRef.current!.getBoundingClientRect(), [courtRef])

    return (
        <Rack
            id={id}
            objects={objects}
            onChange={setObjects}
            canDetach={useCallback((div) =>
                    overlaps(courtBounds(), div.getBoundingClientRect())
                , [courtBounds])}
            onElementDetached={useCallback((r, e: RackedPlayer) =>
                    setComponents((components) => [
                        ...components,
                        placePlayerAt(
                            r.getBoundingClientRect(),
                            courtBounds(),
                            e,
                        ),
                    ])
                , [courtBounds, setComponents])}
            render={useCallback(({team, key}: { team: PlayerTeam, key: string }) => (
                <PlayerPiece
                    team={team}
                    text={key}
                    key={key}
                    hasBall={false}
                />
            ), [])}
        />
    )
}

interface CourtPlayerArrowActionProps {
    playerInfo: PlayerInfo
    player: Player | PlayerPhantom
    isInvalid: boolean

    content: TacticContent
    setContent: (state: SetStateAction<TacticContent>) => void
    setPreviewAction: (state: SetStateAction<ActionPreview | null>) => void
    courtRef: RefObject<HTMLDivElement>
}

function CourtPlayerArrowAction({
                                    playerInfo,
                                    player,
                                    isInvalid,

                                    content,
                                    setContent,
                                    setPreviewAction,
                                    courtRef
                                }: CourtPlayerArrowActionProps) {

    const courtBounds = useCallback(() => courtRef.current!.getBoundingClientRect(), [courtRef])

    return (
        <ArrowAction
            key={1}
            onHeadMoved={(headPos) => {
                const arrowHeadPos = middlePos(headPos)
                const targetIdx = getComponentCollided(
                    headPos,
                    content.components,
                )
                const target = content.components[targetIdx]

                setPreviewAction((action) => ({
                    ...action!,
                    segments: [
                        {
                            next: ratioWithinBase(
                                arrowHeadPos,
                                courtBounds(),
                            ),
                        },
                    ],
                    type: getActionKind(
                        target,
                        playerInfo.ballState,
                    ),
                    isInvalid: !overlaps(headPos, courtBounds()) || !isActionValid(player, target, content.components)
                }))
            }}
            onHeadPicked={(headPos) => {
                (document.activeElement as HTMLElement).blur()

                setPreviewAction({
                    origin: playerInfo.id,
                    type: getActionKind(null, playerInfo.ballState),
                    target: ratioWithinBase(
                        headPos,
                        courtBounds(),
                    ),
                    segments: [
                        {
                            next: ratioWithinBase(
                                middlePos(headPos),
                                courtBounds(),
                            ),
                        },
                    ],
                    isInvalid: false
                })
            }}
            onHeadDropped={(headRect) => {
                if (isInvalid) {
                    setPreviewAction(null)
                    return
                }

                setContent((content) => {
                    let {createdAction, newContent} =
                        createAction(
                            player,
                            courtBounds(),
                            headRect,
                            content,
                        )

                    if (
                        createdAction.type == ActionKind.SHOOT
                    ) {
                        const targetIdx =
                            newContent.components.findIndex(
                                (c) =>
                                    c.id ==
                                    createdAction.target,
                            )
                        newContent = dropBallOnComponent(
                            targetIdx,
                            newContent,
                            false
                        )
                        newContent = updateComponent(
                            {
                                ...(newContent.components.find(
                                    (c) => c.id == player.id,
                                )! as Player | PlayerPhantom),
                                ballState: BallState.PASSED,
                            },
                            newContent,
                        )
                    }


                    return newContent
                })
                setPreviewAction(null)
            }}
        />
    )
}

function isBallOnCourt(content: TacticContent) {
    return (
        content.components.findIndex(
            (c) =>
                (c.type == "player" && (c.ballState === BallState.HOLDS_ORIGIN || c.ballState === BallState.HOLDS_BY_PASS)) ||
                c.type == BALL_TYPE,
        ) != -1
    )
}

function renderCourtObject(courtObject: RackedCourtObject) {
    if (courtObject.key == "ball") {
        return <BallPiece/>
    }
    throw new Error("unknown racked court object " + courtObject.key)
}

function Court({courtType}: { courtType: string }) {
    return (
        <div id="court-image-div">
            {courtType == "PLAIN" ? (
                <PlainCourt id="court-image"/>
            ) : (
                <HalfCourt id="court-image"/>
            )}
        </div>
    )
}

function debounceAsync<A, B>(
    f: (args: A) => Promise<B>,
    delay = 1000,
): (args: A) => Promise<B> {
    let task = 0
    return (args: A) => {
        clearTimeout(task)
        return new Promise((resolve, reject) => {
            task = setTimeout(() => f(args).then(resolve).catch(reject), delay)
        })
    }
}

function useContentState<S>(
    initialContent: S,
    initialSaveState: SaveState,
    saveStateCallback: (s: S) => Promise<SaveState>,
): [S, Dispatch<SetStateAction<S>>, SaveState] {
    const [content, setContent] = useState(initialContent)
    const [savingState, setSavingState] = useState(initialSaveState)

    const setContentSynced = useCallback(
        (newState: SetStateAction<S>) => {
            setContent((content) => {
                const state =
                    typeof newState === "function"
                        ? (newState as (state: S) => S)(content)
                        : newState

                if (state !== content) {
                    setSavingState(SaveStates.Saving)
                    saveStateCallback(state)
                        .then(setSavingState)
                        .catch(() => setSavingState(SaveStates.Err))
                }
                return state
            })
        },
        [saveStateCallback],
    )

    return [content, setContentSynced, savingState]
}