import { $mobx, action, observable, runInAction, trace } from 'mobx';
import { computedFn } from 'mobx-utils';
import { DocServer } from '../client/DocServer';
import { CollectionViewType } from '../client/documents/DocumentTypes';
import { LinkManager } from '../client/util/LinkManager';
import { SerializationHelper } from '../client/util/SerializationHelper';
import { UndoManager } from '../client/util/UndoManager';
import { returnZero } from '../Utils';
import CursorField from './CursorField';
import {
    AclAdmin,
    AclEdit,
    aclLevel,
    AclPrivate,
    AclSelfEdit,
    AclSym,
    DataSym,
    Doc,
    DocListCast,
    DocListCastAsync,
    ForceServerWrite,
    HeightSym,
    HierarchyMapping,
    Initializing,
    LayoutSym,
    ReverseHierarchyMap,
    updateCachedAcls,
    UpdatingFromServer,
    WidthSym,
} from './Doc';
import { Id, OnUpdate, Parent, SelfProxy, ToValue, Update } from './FieldSymbols';
import { List } from './List';
import { ObjectField } from './ObjectField';
import { PrefetchProxy, ProxyField } from './Proxy';
import { RefField } from './RefField';
import { RichTextField } from './RichTextField';
import { SchemaHeaderField } from './SchemaHeaderField';
import { ComputedField } from './ScriptField';
import { ScriptCast, StrCast } from './Types';

function _readOnlySetter(): never {
    throw new Error("Documents can't be modified in read-only mode");
}

const tracing = false;
export function TraceMobx() {
    tracing && trace();
}

const _setterImpl = action(function (target: any, prop: string | symbol | number, value: any, receiver: any): boolean {
    if (SerializationHelper.IsSerializing() || typeof prop === 'symbol') {
        target[prop] = value;
        return true;
    }

    if (value !== undefined) {
        value = value[SelfProxy] || value;
    }
    const curValue = target.__fields[prop];
    if (curValue === value || (curValue instanceof ProxyField && value instanceof RefField && curValue.fieldId === value[Id])) {
        // TODO This kind of checks correctly in the case that curValue is a ProxyField and value is a RefField, but technically
        // curValue should get filled in with value if it isn't already filled in, in case we fetched the referenced field some other way
        return true;
    }
    if (value instanceof RefField) {
        value = new ProxyField(value);
    }
    if (value instanceof ObjectField) {
        if (value[Parent] && value[Parent] !== receiver && !(value instanceof PrefetchProxy)) {
            throw new Error("Can't put the same object in multiple documents at the same time");
        }
        value[Parent] = receiver;
        value[OnUpdate] = updateFunction(target, prop, value, receiver);
    }
    if (curValue instanceof ObjectField) {
        delete curValue[Parent];
        delete curValue[OnUpdate];
    }

    const effectiveAcl = GetEffectiveAcl(target);

    const writeMode = DocServer.getFieldWriteMode(prop as string);
    const fromServer = target[UpdatingFromServer];
    const sameAuthor = fromServer || receiver.author === Doc.CurrentUserEmail;
    const writeToDoc = sameAuthor || effectiveAcl === AclEdit || effectiveAcl === AclAdmin || writeMode !== DocServer.WriteMode.LiveReadonly;
    const writeToServer = (sameAuthor || effectiveAcl === AclEdit || effectiveAcl === AclAdmin || (effectiveAcl === AclSelfEdit && value instanceof RichTextField)) && !DocServer.Control.isReadOnly();

    if (writeToDoc) {
        if (value === undefined) {
            target.__fieldKeys && delete target.__fieldKeys[prop];
            delete target.__fields[prop];
        } else {
            target.__fieldKeys && (target.__fieldKeys[prop] = true);
            target.__fields[prop] = value;
        }

        if (writeToServer) {
            if (value === undefined) target[Update]({ $unset: { ['fields.' + prop]: '' } });
            else target[Update]({ $set: { ['fields.' + prop]: value instanceof ObjectField ? SerializationHelper.Serialize(value) : value === undefined ? null : value } });
            if (prop === 'author' || prop.toString().startsWith('acl')) updateCachedAcls(target);
        } else {
            DocServer.registerDocWithCachedUpdate(receiver, prop as string, curValue);
        }
        !receiver[Initializing] &&
            (!receiver[UpdatingFromServer] || receiver[ForceServerWrite]) &&
            UndoManager.AddEvent({
                redo: () => (receiver[prop] = value),
                undo: () => {
                    const wasUpdate = receiver[UpdatingFromServer];
                    const wasForce = receiver[ForceServerWrite];
                    receiver[ForceServerWrite] = true; // needed since writes aren't propagated to server if UpdatingFromServerIsSet
                    receiver[UpdatingFromServer] = true; // needed if the event caused ACL's to change such that the doc is otherwise no longer editable.
                    receiver[prop] = curValue;
                    receiver[ForceServerWrite] = wasForce;
                    receiver[UpdatingFromServer] = wasUpdate;
                },
                prop: prop?.toString(),
            });
        return true;
    }
    return false;
});

let _setter: (target: any, prop: string | symbol | number, value: any, receiver: any) => boolean = _setterImpl;

export function makeReadOnly() {
    _setter = _readOnlySetter;
}

export function makeEditable() {
    _setter = _setterImpl;
}

export function normalizeEmail(email: string) {
    return email.replace(/\./g, '__');
}
export function denormalizeEmail(email: string) {
    return email.replace(/__/g, '.');
}

/**
 * Copies parent's acl fields to the child
 */
export function inheritParentAcls(parent: Doc, child: Doc) {
    return;
    const dataDoc = parent[DataSym];
    for (const key of Object.keys(dataDoc)) {
        // if the default acl mode is private, then don't inherit the acl-Public permission, but set it to private.
        const permission = key === 'acl-Public' && Doc.defaultAclPrivate ? AclPrivate : dataDoc[key];
        key.startsWith('acl') && distributeAcls(key, permission, child);
    }
}

/**
 * These are the various levels of access a user can have to a document.
 *
 * Admin: a user with admin access to a document can remove/edit that document, add/remove/edit annotations (depending on permissions), as well as change others' access rights to that document.
 *
 * Edit: a user with edit access to a document can remove/edit that document, add/remove/edit annotations (depending on permissions), but not change any access rights to that document.
 *
 * Add: a user with add access to a document can augment documents/annotations to that document but cannot edit or delete anything.
 *
 * View: a user with view access to a document can only view it - they cannot add/remove/edit anything.
 *
 * None: the document is not shared with that user.
 *
 * Unset: Remove a sharing permission (eg., used )
 */
export enum SharingPermissions {
    Unset = 'None',
    Admin = 'Admin',
    Edit = 'Edit',
    SelfEdit = 'Self Edit',
    Augment = 'Augment',
    View = 'View',
    None = 'Not Shared',
}

// return acl from cache or cache the acl and return.
const getEffectiveAclCache = computedFn(function (target: any, user?: string) {
    return getEffectiveAcl(target, user);
}, true);

/**
 * Calculates the effective access right to a document for the current user.
 */
export function GetEffectiveAcl(target: any, user?: string): symbol {
    if (!target) return AclPrivate;
    if (target[UpdatingFromServer]) return AclAdmin;
    return getEffectiveAclCache(target, user); // all changes received from the server must be processed as Admin.  return this directly so that the acls aren't cached (UpdatingFromServer is not observable)
}

function getPropAcl(target: any, prop: string | symbol | number) {
    if (typeof prop === 'symbol' || target[UpdatingFromServer]) return AclAdmin; // requesting the UpdatingFromServer prop or AclSym must always go through to keep the local DB consistent
    if (prop && DocServer.IsPlaygroundField(prop.toString())) return AclEdit; // playground props are always editable
    return GetEffectiveAcl(target);
}

let cachedGroups = observable([] as string[]);
const getCachedGroupByNameCache = computedFn(function (name: string) {
    return cachedGroups.includes(name);
}, true);
export function GetCachedGroupByName(name: string) {
    return getCachedGroupByNameCache(name);
}
export function SetCachedGroups(groups: string[]) {
    runInAction(() => cachedGroups.push(...groups));
}
function getEffectiveAcl(target: any, user?: string): symbol {
    const targetAcls = target[AclSym];
    if (targetAcls?.['acl-Me'] === AclAdmin || GetCachedGroupByName('Admin')) return AclAdmin;

    const userChecked = user || Doc.CurrentUserEmail; // if the current user is the author of the document / the current user is a member of the admin group
    if (targetAcls && Object.keys(targetAcls).length) {
        let effectiveAcl = AclPrivate;
        for (const [key, value] of Object.entries(targetAcls)) {
            // there are issues with storing fields with . in the name, so they are replaced with _ during creation
            // as a result we need to restore them again during this comparison.
            const entity = denormalizeEmail(key.substring(4)); // an individual or a group
            if (HierarchyMapping.get(value as symbol)!.level > HierarchyMapping.get(effectiveAcl)!.level) {
                if (GetCachedGroupByName(entity) || userChecked === entity || entity === 'Me') {
                    effectiveAcl = value as symbol;
                }
            }
        }

        // if there's an overriding acl set through the properties panel or sharing menu, that's what's returned if the user isn't an admin of the document
        //const override = targetAcls['acl-Override'];
        // if (override !== AclUnset && override !== undefined) effectiveAcl = override;

        // if we're in playground mode, return AclEdit (or AclAdmin if that's the user's effectiveAcl)
        return DocServer?.Control?.isReadOnly?.() && HierarchyMapping.get(effectiveAcl)!.level < aclLevel.editable ? AclEdit : effectiveAcl;
    }
    // authored documents are private until an ACL is set.
    const targetAuthor = target.__fields?.author || target.author; // target may be a Doc of Proxy, so check __fields.author and .author
    if (targetAuthor && targetAuthor !== userChecked) return AclPrivate;
    return AclAdmin;
}
/**
 * Recursively distributes the access right for a user across the children of a document and its annotations.
 * @param key the key storing the access right (e.g. acl-groupname)
 * @param acl the access right being stored (e.g. "Can Edit")
 * @param target the document on which this access right is being set
 * @param inheritingFromCollection whether the target is being assigned rights after being dragged into a collection (and so is inheriting the acls from the collection)
 * inheritingFromCollection is not currently being used but could be used if acl assignment defaults change
 */
export function distributeAcls(key: string, acl: SharingPermissions, target: Doc, inheritingFromCollection?: boolean, visited?: Doc[], isDashboard?: boolean) {
    if (!visited) visited = [] as Doc[];
    if (!target || visited.includes(target)) return;

    if ((target._viewType === CollectionViewType.Docking && visited.length > 1) || Doc.GetProto(visited[0]) !== Doc.GetProto(target)) {
        target[key] = acl;
        if (target !== Doc.GetProto(target)) {
            //apparently we can't call updateCachedAcls twice (once for the main dashboard, and again for the nested dashboard...???)
            updateCachedAcls(target);
        }
        return;
    }
    visited.push(target);

    let layoutDocChanged = false; // determines whether fetchProto should be called or not (i.e. is there a change that should be reflected in target[AclSym])
    // if it is inheriting from a collection, it only inherits if A) the key doesn't already exist or B) the right being inherited is more restrictive
    if (GetEffectiveAcl(target) === AclAdmin && (!inheritingFromCollection || !target[key] || ReverseHierarchyMap.get(StrCast(target[key]))!.level > ReverseHierarchyMap.get(acl)!.level)) {
        target[key] = acl;
        layoutDocChanged = true;

        if (isDashboard) {
            DocListCastAsync(target[Doc.LayoutFieldKey(target)]).then(docs => {
                docs?.forEach(d => distributeAcls(key, acl, d, inheritingFromCollection, visited));
            });
        }
    }

    let dataDocChanged = false;
    const dataDoc = target[DataSym];
    if (dataDoc && (!inheritingFromCollection || !dataDoc[key] || ReverseHierarchyMap.get(StrCast(dataDoc[key]))! > ReverseHierarchyMap.get(acl)!)) {
        if (GetEffectiveAcl(dataDoc) === AclAdmin) {
            dataDoc[key] = acl;
            dataDocChanged = true;
        }

        // maps over the links of the document
        LinkManager.Links(dataDoc).forEach(link => distributeAcls(key, acl, link, inheritingFromCollection, visited));

        // maps over the children of the document
        DocListCast(dataDoc[Doc.LayoutFieldKey(dataDoc)]).forEach(d => {
            distributeAcls(key, acl, d, inheritingFromCollection, visited);
            distributeAcls(key, acl, d[DataSym], inheritingFromCollection, visited);
        });

        // maps over the annotations of the document
        DocListCast(dataDoc[Doc.LayoutFieldKey(dataDoc) + '-annotations']).forEach(d => {
            distributeAcls(key, acl, d, inheritingFromCollection, visited);
            distributeAcls(key, acl, d[DataSym], inheritingFromCollection, visited);
        });
    }

    layoutDocChanged && updateCachedAcls(target); // updates target[AclSym] when changes to acls have been made
    dataDocChanged && updateCachedAcls(dataDoc);
}

export function setter(target: any, in_prop: string | symbol | number, value: any, receiver: any): boolean {
    let prop = in_prop;
    const effectiveAcl = in_prop === 'constructor' || typeof in_prop === 'symbol' ? AclAdmin : getPropAcl(target, prop);
    if (effectiveAcl !== AclEdit && effectiveAcl !== AclAdmin && !(effectiveAcl === AclSelfEdit && value instanceof RichTextField)) return true;
    // if you're trying to change an acl but don't have Admin access / you're trying to change it to something that isn't an acceptable acl, you can't
    if (typeof prop === 'string' && prop.startsWith('acl') && (effectiveAcl !== AclAdmin || ![...Object.values(SharingPermissions), undefined].includes(value))) return true;

    if (typeof prop === 'string' && prop !== '__id' && prop !== '__fields' && prop.startsWith('_')) {
        if (!prop.startsWith('__')) prop = prop.substring(1);
        if (target.__LAYOUT__) {
            target.__LAYOUT__[prop] = value;
            return true;
        }
    }
    if (target.__fields[prop] instanceof ComputedField) {
        if (target.__fields[prop].setterscript && value !== undefined && !(value instanceof ComputedField)) {
            return ScriptCast(target.__fields[prop])?.setterscript?.run({ self: target[SelfProxy], this: target[SelfProxy], value }).success ? true : false;
        }
    }
    return _setter(target, prop, value, receiver);
}

export function getter(target: any, prop: string | symbol, proxy: any): any {
    // prettier-ignore
    switch (prop) {
        case 'then' :   return undefined;
        case '__fields' :   case '__id':  
        case 'constructor': case 'toString': case 'valueOf':  
        case 'factory':     case 'serializeInfo': 
                        return target[prop];
        case AclSym :   return target[AclSym];
        case $mobx:     return target.__fields[prop];
        case LayoutSym: return target.__LAYOUT__;
        case HeightSym: case WidthSym: if (GetEffectiveAcl(target) === AclPrivate) return returnZero;
        default :
            if (typeof prop === 'symbol')  return target[prop];
            if (prop.startsWith('isMobX')) return target[prop];
            if (prop.startsWith('__'))     return target[prop];
            if (GetEffectiveAcl(target) === AclPrivate && prop !== 'author') return undefined;
    }

    const layout_prop = prop.startsWith('_') ? prop.substring(1) : undefined;
    if (layout_prop && target.__LAYOUT__) return target.__LAYOUT__[layout_prop];
    return getFieldImpl(target, layout_prop ?? prop, proxy);
}

function getFieldImpl(target: any, prop: string | number, proxy: any, ignoreProto: boolean = false): any {
    const field = target.__fields[prop];
    const value = field?.[ToValue]?.(proxy); // converts ComputedFields to values, or unpacks ProxyFields into Proxys
    if (value) return value.value;
    if (field === undefined && !ignoreProto && prop !== 'proto') {
        const proto = getFieldImpl(target, 'proto', proxy, true); //TODO tfs: instead of proxy we could use target[SelfProxy]... I don't which semantics we want or if it really matters
        if (proto instanceof Doc && GetEffectiveAcl(proto) !== AclPrivate) {
            return getFieldImpl(proto, prop, proxy, ignoreProto);
        }
    }
    return field;
}
export function getField(target: any, prop: string | number, ignoreProto: boolean = false): any {
    return getFieldImpl(target, prop, target[SelfProxy], ignoreProto);
}

export function deleteProperty(target: any, prop: string | number | symbol) {
    if (typeof prop === 'symbol') {
        delete target[prop];
    } else {
        target[SelfProxy][prop] = undefined;
    }
    return true;
}

export function updateFunction(target: any, prop: any, value: any, receiver: any) {
    let lastValue = ObjectField.MakeCopy(value);
    return (diff?: any) => {
        const op =
            diff?.op === '$addToSet'
                ? { $addToSet: { ['fields.' + prop]: SerializationHelper.Serialize(new List<Doc>(diff.items)) } }
                : diff?.op === '$remFromSet'
                ? { $remFromSet: { ['fields.' + prop]: SerializationHelper.Serialize(new List<Doc>(diff.items)), hint : diff.hint } }
                : { $set: { ['fields.' + prop]: SerializationHelper.Serialize(value) } };
        !op.$set && ((op as any).length = diff.length);
        const prevValue = ObjectField.MakeCopy(lastValue as List<any>);
        lastValue = ObjectField.MakeCopy(value);
        const newValue = ObjectField.MakeCopy(value);

        if (!(value instanceof CursorField) && !value?.some?.((v: any) => v instanceof CursorField)) {
            !receiver[UpdatingFromServer] &&
                UndoManager.AddEvent(
                    diff?.op === '$addToSet'
                        ? {
                              redo: () => {
                                  receiver[prop].push(...diff.items.map((item: any) => item.value ?? item));
                                  lastValue = ObjectField.MakeCopy(receiver[prop]);
                              },
                              undo: action(() => {
                                  // console.log("undo $add: " + prop, diff.items) // bcz: uncomment to log undo
                                  diff.items.forEach((item: any) => {
                                      if (item instanceof SchemaHeaderField) {
                                          const ind = receiver[prop].findIndex((ele: any) => ele instanceof SchemaHeaderField && ele.heading === item.heading);
                                          ind !== -1 && receiver[prop].splice(ind, 1);
                                      } else {
                                          const ind = receiver[prop].indexOf(item.value ?? item);
                                          ind !== -1 && receiver[prop].splice(ind, 1);
                                      }
                                  });
                                  lastValue = ObjectField.MakeCopy(receiver[prop]);
                              }),
                              prop: '',
                          }
                        : diff?.op === '$remFromSet'
                        ? {
                              redo: action(() => {
                                  diff.items.forEach((item: any) => {
                                      const ind = item instanceof SchemaHeaderField ? receiver[prop].findIndex((ele: any) => ele instanceof SchemaHeaderField && ele.heading === item.heading) : receiver[prop].indexOf(item.value ?? item);
                                      ind !== -1 && receiver[prop].splice(ind, 1);
                                  });
                                  lastValue = ObjectField.MakeCopy(receiver[prop]);
                              }),
                              undo: () => {
                                  // console.log("undo $rem: " + prop, diff.items) // bcz: uncomment to log undo
                                  diff.items.forEach((item: any) => {
                                      if (item instanceof SchemaHeaderField) {
                                          const ind = (prevValue as List<any>).findIndex((ele: any) => ele instanceof SchemaHeaderField && ele.heading === item.heading);
                                          ind !== -1 && receiver[prop].findIndex((ele: any) => ele instanceof SchemaHeaderField && ele.heading === item.heading) === -1 && receiver[prop].splice(ind, 0, item);
                                      } else {
                                          const ind = (prevValue as List<any>).indexOf(item.value ?? item);
                                          ind !== -1 && receiver[prop].indexOf(item.value ?? item) === -1 && receiver[prop].splice(ind, 0, item);
                                      }
                                  });
                                  lastValue = ObjectField.MakeCopy(receiver[prop]);
                              },
                              prop: '',
                          }
                        : {
                              redo: () => {
                                  receiver[prop] = ObjectField.MakeCopy(newValue as List<any>);
                                  lastValue = ObjectField.MakeCopy(receiver[prop]);
                              },
                              undo: () => {
                                  // console.log("undo list: " + prop, receiver[prop]) // bcz: uncomment to log undo
                                  receiver[prop] = ObjectField.MakeCopy(prevValue as List<any>);
                                  lastValue = ObjectField.MakeCopy(receiver[prop]);
                              },
                              prop: '',
                          }
                );
        }
        target[Update](op);
    };
}