import type { ElectronApplication } from '@playwright/test';

export const DATABASE_REQUEST_IDENTITY_CAPTURE_STATE_KEY =
    '__iptvnatorM3uRefreshDatabaseRequestIdentityCapture';

export interface DatabaseRequestIdentity {
    ipcCallId: number | null;
    operationId: string | null;
    operationIdUnavailableReason: string | null;
    sourceEpochMs: number | null;
}

export interface PreloadDatabaseSuccessMarker {
    ipcCallId: number;
    operation: 'DB_GET_APP_PLAYLIST' | 'DB_UPSERT_APP_PLAYLIST';
    operationId: string | null;
    playlistId: string;
    sourceEpochMs: number;
}

export interface DatabaseRequestIdentityCaptureApi {
    matchDatabaseRequest(message: unknown): DatabaseRequestIdentity;
    start(): void;
    stop(): void;
    successMarkerCount(): number;
    takeSuccessMarkers(): readonly PreloadDatabaseSuccessMarker[];
}

interface DatabaseRequestIdentityElectron {
    readonly ipcMain: {
        on(
            channel: string,
            listener: (event: unknown, marker: unknown) => void
        ): void;
    };
}

export function installDatabaseRequestIdentityCaptureInMain(
    { ipcMain }: DatabaseRequestIdentityElectron,
    stateKey: string
): void {
    type JsonRecord = Record<string, unknown>;
    interface PendingMarker {
        readonly ipcCallId: number;
        readonly operation: string;
        readonly operationId: string | null;
        readonly operationIdUnavailableReason: string | null;
        readonly playlistId: string;
        readonly sourceEpochMs: number;
    }
    interface PendingRequest {
        readonly identity: DatabaseRequestIdentity;
        readonly operation: string;
        readonly playlistId: string;
    }
    interface QuarantinedKey {
        readonly operation: string;
        readonly playlistId: string;
    }

    const target = globalThis as unknown as Record<string, unknown>;
    if (target[stateKey] !== undefined) {
        return;
    }

    const markerChannel = 'IPTVNATOR_PERF_CAPTURE_MARKER';
    const markerMethodToOperation: Readonly<Record<string, string>> = {
        dbGetAppPlaylist: 'DB_GET_APP_PLAYLIST',
        dbUpsertAppPlaylist: 'DB_UPSERT_APP_PLAYLIST',
    };
    let active = false;
    let pendingMarkers: PendingMarker[] = [];
    let pendingRequests: PendingRequest[] = [];
    let quarantinedKeys: QuarantinedKey[] = [];
    let successMarkers: PreloadDatabaseSuccessMarker[] = [];

    const readRecord = (value: unknown): JsonRecord | null =>
        typeof value === 'object' && value !== null
            ? (value as JsonRecord)
            : null;
    const readPlaylistId = (
        operation: string,
        payload: unknown
    ): string | null => {
        const value = readRecord(payload);
        if (!value) {
            return null;
        }
        const playlistId =
            operation === 'DB_UPSERT_APP_PLAYLIST'
                ? value['_id']
                : value['playlistId'];
        return typeof playlistId === 'string' && playlistId.length > 0
            ? playlistId
            : null;
    };
    const matches = (
        candidate: { operation: string; playlistId: string },
        operation: string,
        playlistId: string
    ): boolean =>
        candidate.operation === operation &&
        candidate.playlistId === playlistId;
    const markAmbiguous = (requests: PendingRequest[]): void => {
        for (const request of requests) {
            request.identity.ipcCallId = null;
            request.identity.operationId = null;
            request.identity.operationIdUnavailableReason =
                'preload-performance-marker-ambiguous';
            request.identity.sourceEpochMs = null;
        }
    };
    const unavailableIdentity = (reason: string): DatabaseRequestIdentity => ({
        ipcCallId: null,
        operationId: null,
        operationIdUnavailableReason: reason,
        sourceEpochMs: null,
    });
    const identityFromMarker = (
        marker: PendingMarker
    ): DatabaseRequestIdentity => ({
        ipcCallId: marker.ipcCallId,
        operationId: marker.operationId,
        operationIdUnavailableReason: marker.operationIdUnavailableReason,
        sourceEpochMs: marker.sourceEpochMs,
    });
    const applyMarker = (
        identity: DatabaseRequestIdentity,
        marker: PendingMarker
    ): void => {
        identity.ipcCallId = marker.ipcCallId;
        identity.operationId = marker.operationId;
        identity.operationIdUnavailableReason =
            marker.operationIdUnavailableReason;
        identity.sourceEpochMs = marker.sourceEpochMs;
    };
    const isQuarantined = (operation: string, playlistId: string): boolean =>
        quarantinedKeys.some((key) => matches(key, operation, playlistId));
    const quarantine = (operation: string, playlistId: string): void => {
        if (!isQuarantined(operation, playlistId)) {
            quarantinedKeys.push({ operation, playlistId });
        }
        const requestCandidates = pendingRequests.filter((request) =>
            matches(request, operation, playlistId)
        );
        markAmbiguous(requestCandidates);
        pendingRequests = pendingRequests.filter(
            (request) => !matches(request, operation, playlistId)
        );
        pendingMarkers = pendingMarkers.filter(
            (marker) => !matches(marker, operation, playlistId)
        );
    };

    ipcMain.on(markerChannel, (_event, input) => {
        if (!active) {
            return;
        }
        const marker = readRecord(input);
        const correlationState = marker?.['correlationState'];
        const operation =
            typeof marker?.['method'] === 'string'
                ? markerMethodToOperation[marker['method']]
                : undefined;
        const operationId = marker?.['operationId'];
        const playlistId = marker?.['playlistId'];
        const ipcCallId = marker?.['ipcCallId'];
        const sourceEpochMs = marker?.['sourceEpochMs'];
        const validMarkerIdentity =
            operation !== undefined &&
            typeof playlistId === 'string' &&
            playlistId.length > 0 &&
            Number.isSafeInteger(ipcCallId) &&
            Number(ipcCallId) >= 1 &&
            typeof sourceEpochMs === 'number' &&
            Number.isFinite(sourceEpochMs) &&
            sourceEpochMs >= 0;
        if (
            marker?.['phase'] === 'success' &&
            (correlationState === 'correlated' ||
                correlationState === 'uncorrelated') &&
            marker['invalidReason'] === null &&
            validMarkerIdentity &&
            (correlationState !== 'correlated' ||
                (typeof operationId === 'string' &&
                    operationId.length > 0))
        ) {
            successMarkers.push({
                ipcCallId: Number(ipcCallId),
                operation: operation as PreloadDatabaseSuccessMarker['operation'],
                operationId:
                    correlationState === 'correlated'
                        ? String(operationId)
                        : null,
                playlistId,
                sourceEpochMs,
            });
            return;
        }
        if (
            !marker ||
            marker['phase'] !== 'start' ||
            (correlationState !== 'correlated' &&
                correlationState !== 'uncorrelated') ||
            marker['invalidReason'] !== null
        ) {
            return;
        }
        const correlatedOperationId =
            correlationState === 'correlated' &&
            typeof operationId === 'string' &&
            operationId.length > 0
                ? operationId
                : null;
        if (
            operation === undefined ||
            (correlationState === 'correlated' &&
                correlatedOperationId === null) ||
            typeof playlistId !== 'string' ||
            playlistId.length === 0 ||
            !Number.isSafeInteger(ipcCallId) ||
            Number(ipcCallId) < 1 ||
            typeof sourceEpochMs !== 'number' ||
            !Number.isFinite(sourceEpochMs) ||
            sourceEpochMs < 0
        ) {
            return;
        }
        const pendingMarker: PendingMarker = {
            ipcCallId: Number(ipcCallId),
            operation,
            operationId: correlatedOperationId,
            operationIdUnavailableReason:
                correlationState === 'correlated'
                    ? null
                    : 'preload-performance-marker-uncorrelated',
            playlistId,
            sourceEpochMs,
        };

        if (isQuarantined(operation, playlistId)) {
            return;
        }
        const requestCandidates = pendingRequests.filter((request) =>
            matches(request, operation, playlistId)
        );
        if (requestCandidates.length === 1) {
            const request = requestCandidates[0];
            if (!request) {
                return;
            }
            applyMarker(request.identity, pendingMarker);
            pendingRequests = pendingRequests.filter(
                (candidate) => candidate !== request
            );
            return;
        }
        if (requestCandidates.length > 1) {
            quarantine(operation, playlistId);
            return;
        }

        pendingMarkers.push(pendingMarker);
        pendingMarkers.sort((left, right) => left.ipcCallId - right.ipcCallId);
    });

    const api: DatabaseRequestIdentityCaptureApi = {
        matchDatabaseRequest: (input) => {
            const message = readRecord(input);
            const operation = message?.['operation'];
            const playlistId =
                typeof operation === 'string'
                    ? readPlaylistId(operation, message?.['payload'])
                    : null;
            if (
                !active ||
                (operation !== 'DB_GET_APP_PLAYLIST' &&
                    operation !== 'DB_UPSERT_APP_PLAYLIST') ||
                playlistId === null
            ) {
                return unavailableIdentity(
                    'preload-performance-marker-not-applicable'
                );
            }

            if (isQuarantined(operation, playlistId)) {
                return unavailableIdentity(
                    'preload-performance-marker-ambiguous'
                );
            }
            const markerCandidates = pendingMarkers.filter((marker) =>
                matches(marker, operation, playlistId)
            );
            if (markerCandidates.length === 1) {
                const marker = markerCandidates[0];
                if (!marker) {
                    return unavailableIdentity(
                        'preload-performance-marker-missing'
                    );
                }
                pendingMarkers = pendingMarkers.filter(
                    (candidate) => candidate !== marker
                );
                return identityFromMarker(marker);
            }
            if (markerCandidates.length > 1) {
                quarantine(operation, playlistId);
                return unavailableIdentity(
                    'preload-performance-marker-ambiguous'
                );
            }

            const identity = unavailableIdentity(
                'preload-performance-marker-missing'
            );
            pendingRequests.push({
                identity,
                operation,
                playlistId,
            });
            return identity;
        },
        start: () => {
            pendingMarkers = [];
            pendingRequests = [];
            quarantinedKeys = [];
            successMarkers = [];
            active = true;
        },
        stop: () => {
            active = false;
            pendingMarkers = [];
            pendingRequests = [];
            quarantinedKeys = [];
            successMarkers = [];
        },
        successMarkerCount: () => successMarkers.length,
        takeSuccessMarkers: () => {
            const captured = Object.freeze([...successMarkers]);
            successMarkers = [];
            return captured;
        },
    };
    target[stateKey] = api;
}

export async function installDatabaseRequestIdentityCapture(
    electronApp: ElectronApplication
): Promise<void> {
    await electronApp.evaluate(
        installDatabaseRequestIdentityCaptureInMain,
        DATABASE_REQUEST_IDENTITY_CAPTURE_STATE_KEY
    );
}