import { defineStore } from 'pinia';
import { ref } from 'vue';
import { ALTCHA_REQUEST_HEADER } from '@/consts/altchaRequestHeader';
import { api } from '@/plugins/axios';
import { useAltchaStore } from '@/stores/altcha';
import { useMetadataStore } from '@/stores/metadata';
import type { CreateHotlinkUploadRequest } from '@/types/upload/CreateHotlinkUploadRequest';
import type { CreateZkUploadRequest } from '@/types/upload/CreateZkUploadRequest';
import type { CreatedUploadResult } from '@/types/upload/CreatedUploadResult';
import type { UploadBatchSettingsForm } from '@/types/upload/UploadBatchSettingsForm';
import type { UploadQueueEntry } from '@/types/upload/UploadQueueEntry';
import { makeKeyFromFile } from '@/utils/file/makeKeyFromFile';
import { buildUploadOptionsFromBatchSettings } from '@/utils/upload/buildUploadOptionsFromBatchSettings';
import { buildZkUploadPrepareOptionsFromBatchSettings } from '@/utils/upload/buildZkUploadPrepareOptionsFromBatchSettings';
import { prepareHotlinkUploadRequest } from '@/utils/upload/prepareHotlinkUploadRequest';
import { prepareZkUploadRequest } from '@/utils/upload/prepareZkUploadRequest';
import type { PreparedZkUploadRequest } from '@/types/upload/PreparedZkUploadRequest';
import type { PreparedHotlinkUploadRequest } from '@/types/upload/PreparedHotlinkUploadRequest';

const UPLOAD_IDLE_MESSAGE = 'Waiting to upload...';
const UPLOAD_QUEUED_MESSAGE = 'Upload queued';
const UPLOAD_PREPARING_MESSAGE = 'Preparing upload...';
const UPLOAD_UPLOADING_MESSAGE = 'Uploading...';
const UPLOAD_UPLOADED_MESSAGE = 'Uploaded';
const UPLOAD_READ_ERROR_MESSAGE = 'Could not read image';
const UPLOAD_PROOF_OF_WORK_ERROR_MESSAGE = 'Proof of work failed';
const UPLOAD_FAILED_MESSAGE = 'Upload failed';
const UPLOAD_SKIPPED_METADATA_MESSAGE = 'Metadata not ready';
const UPLOAD_STRIPPED_MISSING_MESSAGE = 'Stripped image missing';
const UPLOAD_UNKNOWN_MODE_MESSAGE = 'Unknown share mode';

const UPLOAD_IDLE_ENTRY: UploadQueueEntry = {
    status: 'idle',
    message: UPLOAD_IDLE_MESSAGE
};

const UPLOAD_QUEUED_ENTRY: UploadQueueEntry = {
    status: 'queued',
    message: UPLOAD_QUEUED_MESSAGE
};

const UPLOAD_UPLOADING_ENTRY: UploadQueueEntry = {
    status: 'uploading',
    message: UPLOAD_UPLOADING_MESSAGE
};

const UPLOAD_FAILED_ENTRY: UploadQueueEntry = {
    status: 'failed',
    message: UPLOAD_FAILED_MESSAGE
};

const UPLOAD_STRIPPED_MISSING_ENTRY: UploadQueueEntry = {
    status: 'failed',
    message: UPLOAD_STRIPPED_MISSING_MESSAGE
};

export const useUploadStore = defineStore('upload', () => {
    const uploadByKey = ref<Record<string, UploadQueueEntry>>({});

    const metadataStore = useMetadataStore();
    const altchaStore = useAltchaStore();

    const { getPreview, getStrippedBlob } = metadataStore;

    const setUploadEntry = (key: string, entry: UploadQueueEntry): void => {
        uploadByKey.value = { ...uploadByKey.value, [key]: entry };
    };

    const getUpload = (file?: File | null): UploadQueueEntry => {
        if (!file) {
            return UPLOAD_IDLE_ENTRY;
        }

        const key = makeKeyFromFile(file);

        return uploadByKey.value[key] ?? UPLOAD_IDLE_ENTRY;
    };

    const clearAllUploads = (): void => {
        uploadByKey.value = {};
    };

    const uploadZk = async (body: CreateZkUploadRequest, altcha?: string): Promise<CreatedUploadResult> => {
        const { data } = await api.post<CreatedUploadResult>('/uploads/zk', body, {
            headers: getUploadRequestHeaders(altcha)
        });

        return data;
    };

    const uploadHotlink = async (body: CreateHotlinkUploadRequest, altcha?: string): Promise<CreatedUploadResult> => {
        const { data } = await api.post<CreatedUploadResult>('/uploads/hotlink', body, {
            headers: getUploadRequestHeaders(altcha)
        });

        return data;
    };

    const deleteUpload = async (uploadId: string, deleteToken: string): Promise<void> => {
        await api.delete(`/uploads/${uploadId}`, {
            params: { delete_token: deleteToken }
        });
    };

    const getUploadRequestHeaders = (altcha?: string) => (altcha ? { [ALTCHA_REQUEST_HEADER]: altcha } : undefined);

    const uploadBatch = async (
        files: readonly File[],
        settings: UploadBatchSettingsForm,
        uploadDespiteMetadataFailure = false
    ): Promise<void> => {
        initializeBatchUploadState(files, uploadDespiteMetadataFailure);

        for (const file of files) {
            const key = makeKeyFromFile(file);
            const entry = uploadByKey.value[key];

            if (!entry || entry.status !== 'queued') {
                continue;
            }

            const strippedBlob = getStrippedBlob(file);
            const preview = getPreview(file);
            const uploadOriginal = !strippedBlob && uploadDespiteMetadataFailure && preview.status === 'error';

            if (!strippedBlob && !uploadOriginal) {
                setUploadEntry(key, UPLOAD_STRIPPED_MISSING_ENTRY);
                continue;
            }

            const sourceBlob = strippedBlob ?? file;

            setUploadEntry(key, { status: 'preparing', message: UPLOAD_PREPARING_MESSAGE });
            let plaintext: Uint8Array;
            const mimeType = sourceBlob.type || file.type || 'application/octet-stream';

            try {
                const arrayBuffer = await sourceBlob.arrayBuffer();

                plaintext = new Uint8Array(arrayBuffer);
            } catch (error) {
                console.error('[upload] read stripped blob failed', { file: file.name, error });

                setUploadEntry(key, {
                    status: 'failed',
                    message: UPLOAD_READ_ERROR_MESSAGE
                });
                continue;
            }

            let altcha: string | undefined;

            try {
                altcha = await altchaStore.runProofOfWork();
            } catch (error) {
                console.error('[upload] altcha failed', { file: file.name, error });

                setUploadEntry(key, {
                    status: 'failed',
                    message: UPLOAD_PROOF_OF_WORK_ERROR_MESSAGE
                });
                continue;
            }

            if (settings.mode === 'zk') {
                const options = buildZkUploadPrepareOptionsFromBatchSettings(settings);

                let prepared: PreparedZkUploadRequest;

                try {
                    prepared = await prepareZkUploadRequest(plaintext, options);
                } catch (error) {
                    console.error('[upload] encrypt failed', { file: file.name, error });

                    setUploadEntry(key, UPLOAD_FAILED_ENTRY);
                    continue;
                }

                setUploadEntry(key, UPLOAD_UPLOADING_ENTRY);
                try {
                    const { request, fragmentKey } = prepared;

                    const result = await uploadZk(request, altcha);

                    setUploadEntry(key, {
                        status: 'uploaded',
                        message: UPLOAD_UPLOADED_MESSAGE,
                        uploadId: result.id,
                        mode: 'zk',
                        deleteToken: result.deleteToken,
                        urlSecret: fragmentKey
                    });
                } catch (error) {
                    console.error('[upload] upload failed', { file: file.name, error });

                    setUploadEntry(key, UPLOAD_FAILED_ENTRY);
                }
            } else if (settings.mode === 'hotlink') {
                const options = buildUploadOptionsFromBatchSettings(settings);

                let prepared: PreparedHotlinkUploadRequest;

                try {
                    prepared = await prepareHotlinkUploadRequest(plaintext, mimeType, options);
                } catch (error) {
                    console.error('[upload] encrypt failed', { file: file.name, error });

                    setUploadEntry(key, UPLOAD_FAILED_ENTRY);
                    continue;
                }

                setUploadEntry(key, UPLOAD_UPLOADING_ENTRY);
                try {
                    const { request, secret } = prepared;

                    const result = await uploadHotlink(request, altcha);

                    setUploadEntry(key, {
                        status: 'uploaded',
                        message: UPLOAD_UPLOADED_MESSAGE,
                        uploadId: result.id,
                        mode: 'hotlink',
                        deleteToken: result.deleteToken,
                        urlSecret: secret
                    });
                } catch (error) {
                    console.error('[upload] upload failed', { file: file.name, error });

                    setUploadEntry(key, UPLOAD_FAILED_ENTRY);
                }
            } else {
                setUploadEntry(key, { status: 'failed', message: UPLOAD_UNKNOWN_MODE_MESSAGE });
            }
        }
    };

    const initializeBatchUploadState = (files: readonly File[], uploadDespiteMetadataFailure: boolean): void => {
        uploadByKey.value = {};

        for (const file of files) {
            const key = makeKeyFromFile(file);
            const preview = getPreview(file);
            const strippedBlob = getStrippedBlob(file);

            if (preview.status === 'ready') {
                if (strippedBlob) {
                    setUploadEntry(key, UPLOAD_QUEUED_ENTRY);
                } else {
                    setUploadEntry(key, UPLOAD_STRIPPED_MISSING_ENTRY);
                }
            } else if (preview.status === 'error' && uploadDespiteMetadataFailure) {
                setUploadEntry(key, UPLOAD_QUEUED_ENTRY);
            } else {
                setUploadEntry(key, { status: 'skipped', message: UPLOAD_SKIPPED_METADATA_MESSAGE });
            }

        }
    };

    return {
        uploadByKey,
        getUpload,
        clearAllUploads,
        uploadBatch,
        uploadZk,
        uploadHotlink,
        deleteUpload
    };
});