/* jslint node: true */
/* eslint-disable no-console */
'use strict';

const printUsageAndSetExitCode	= require('./oputil_common.js').printUsageAndSetExitCode;
const ExitCodes					= require('./oputil_common.js').ExitCodes;
const argv						= require('./oputil_common.js').argv;
const initConfigAndDatabases	= require('./oputil_common.js').initConfigAndDatabases;
const getHelpFor				= require('./oputil_help.js').getHelpFor;
const {
    getAreaAndStorage,
    looksLikePattern
}								= require('./oputil_common.js');
const Errors					= require('../enig_error.js').Errors;

const async						= require('async');
const fs						= require('graceful-fs');
const paths						= require('path');
const _							= require('lodash');
const moment					= require('moment');
const inq						= require('inquirer');
const glob						= require('glob');

exports.handleFileBaseCommand			= handleFileBaseCommand;

/*
	:TODO:

	Global options:
		--yes: assume yes
		--no-prompt: try to avoid user input

	Prompt for import and description before scan
		* Only after finding duplicate-by-path
		* Default to filename -> desc if auto import

*/

let fileArea;	//	required during init

function finalizeEntryAndPersist(isUpdate, fileEntry, descHandler, cb) {
    async.series(
        [
            function getDescFromHandlerIfNeeded(callback) {
                if((fileEntry.desc && fileEntry.desc.length > 0 ) && !argv['desc-file']) {
                    return callback(null);	//	we have a desc already and are NOT overriding with desc file
                }

                if(!descHandler) {
                    return callback(null);	//	not much we can do!
                }

                const desc = descHandler.getDescription(fileEntry.fileName);
                if(desc) {
                    fileEntry.desc = desc;
                }
                return callback(null);
            },
            function getDescFromUserIfNeeded(callback) {
                if(fileEntry.desc && fileEntry.desc.length > 0 ) {
                    return callback(null);
                }

                const getDescFromFileName	= require('../../core/file_base_area.js').getDescFromFileName;
                const descFromFile			= getDescFromFileName(fileEntry.fileName);

                if(false === argv.prompt) {
                    fileEntry.desc = descFromFile;
                    return callback(null);
                }

                const questions = [
                    {
                        name	: 'desc',
                        message	: `Description for ${fileEntry.fileName}:`,
                        type	: 'input',
                        default	: descFromFile,
                    }
                ];

                inq.prompt(questions).then( answers => {
                    fileEntry.desc = answers.desc;
                    return callback(null);
                });
            },
            function persist(callback) {
                fileEntry.persist(isUpdate, err => {
                    return callback(err);
                });
            }
        ],
        err => {
            return cb(err);
        }
    );
}

const SCAN_EXCLUDE_FILENAMES = [ 'DESCRIPT.ION', 'FILES.BBS' ];

function loadDescHandler(path, cb) {
    const DescIon = require('../../core/descript_ion_file.js');

    //	:TODO: support FILES.BBS also

    DescIon.createFromFile(path, (err, descHandler) => {
        return cb(err, descHandler);
    });
}

function scanFileAreaForChanges(areaInfo, options, cb) {

    const storageLocations = fileArea.getAreaStorageLocations(areaInfo).filter(sl => {
        return options.areaAndStorageInfo.find(asi => {
            return !asi.storageTag || sl.storageTag === asi.storageTag;
        });
    });

    function updateTags(fe) {
        if(Array.isArray(options.tags)) {
            fe.hashTags = new Set(options.tags);
        }
    }

    const FileEntry = require('../file_entry.js');

    const readDir = options.glob ?
        (dir, next) => {
            return glob(options.glob, { cwd : dir, nodir : true }, next);
        } :
        (dir, next) => {
            return fs.readdir(dir, next);
        };

    async.eachSeries(storageLocations, (storageLoc, nextLocation) => {
        async.waterfall(
            [
                function initDescFile(callback) {
                    if(options.descFileHandler) {
                        return callback(null, options.descFileHandler);	//	we're going to use the global handler
                    }

                    loadDescHandler(paths.join(storageLoc.dir, 'DESCRIPT.ION'), (err, descHandler) => {
                        return callback(null, descHandler);
                    });
                },
                function scanPhysFiles(descHandler, callback) {
                    const physDir = storageLoc.dir;

                    readDir(physDir, (err, files) => {
                        if(err) {
                            return callback(err);
                        }

                        async.eachSeries(files, (fileName, nextFile) => {
                            const fullPath = paths.join(physDir, fileName);

                            if(SCAN_EXCLUDE_FILENAMES.includes(fileName.toUpperCase())) {
                                console.info(`Excluding ${fullPath}`);
                                return nextFile(null);
                            }

                            fs.stat(fullPath, (err, stats) => {
                                if(err) {
                                    //	:TODO: Log me!
                                    return nextFile(null);	//	always try next file
                                }

                                if(!stats.isFile()) {
                                    return nextFile(null);
                                }

                                process.stdout.write(`Scanning ${fullPath}... `);

                                async.series(
                                    [
                                        function quickCheck(next) {
                                            if(!options.quick) {
                                                return next(null);
                                            }

                                            FileEntry.quickCheckExistsByPath(fullPath, (err, exists) => {
                                                if(exists) {
                                                    console.info('Dupe');
                                                    return nextFile(null);
                                                }

                                                return next(null);
                                            });
                                        },
                                        function fullScan() {
                                            fileArea.scanFile(
                                                fullPath,
                                                {
                                                    areaTag		: areaInfo.areaTag,
                                                    storageTag	: storageLoc.storageTag
                                                },
                                                (err, fileEntry, dupeEntries) => {
                                                    if(err) {
                                                        console.info(`Error: ${err.message}`);
                                                        return nextFile(null);	//	try next anyway
                                                    }

                                                    //
                                                    //	We'll update the entry if the following conditions are met:
                                                    //	* We have a single duplicate, and:
                                                    //	* --update was passed or the existing entry's desc,
                                                    //	  longDesc, or est_release_year meta are blank/empty
                                                    //
                                                    if(argv.update && 1 === dupeEntries.length) {
                                                        const FileEntry		= require('../../core/file_entry.js');
                                                        const existingEntry	= new FileEntry();

                                                        return existingEntry.load(dupeEntries[0].fileId, err => {
                                                            if(err) {
                                                                console.info('Dupe (cannot update)');
                                                                return nextFile(null);
                                                            }

                                                            //
                                                            //	Update only if tags or desc changed
                                                            //
                                                            const optTags	= Array.isArray(options.tags) ? new Set(options.tags) : existingEntry.hashTags;
                                                            const tagsEq	= _.isEqual(optTags, existingEntry.hashTags);

                                                            if( tagsEq &&
																fileEntry.desc === existingEntry.desc &&
																fileEntry.descLong == existingEntry.descLong &&
																fileEntry.meta.est_release_year == existingEntry.meta.est_release_year)
                                                            {
                                                                console.info('Dupe');
                                                                return nextFile(null);
                                                            }

                                                            console.info('Dupe (updating)');

                                                            //	don't allow overwrite of values if new version is blank
                                                            existingEntry.desc 					= fileEntry.desc || existingEntry.desc;
                                                            existingEntry.descLong				= fileEntry.descLong || existingEntry.descLong;

                                                            if(fileEntry.meta.est_release_year) {
                                                                existingEntry.meta.est_release_year	= fileEntry.meta.est_release_year;
                                                            }

                                                            updateTags(existingEntry);

                                                            finalizeEntryAndPersist(true, existingEntry, descHandler, err => {
                                                                return nextFile(err);
                                                            });
                                                        });
                                                    } else if(dupeEntries.length > 0) {
                                                        console.info('Dupe');
                                                        return nextFile(null);
                                                    }

                                                    console.info('Done!');
                                                    updateTags(fileEntry);

                                                    finalizeEntryAndPersist(false, fileEntry, descHandler, err => {
                                                        return nextFile(err);
                                                    });
                                                }
                                            );
                                        }
                                    ]
                                );
                            });
                        }, err => {
                            return callback(err);
                        });
                    });
                },
                function scanDbEntries(callback) {
                    //	:TODO: Look @ db entries for area that were *not* processed above
                    return callback(null);
                }
            ],
            err => {
                return nextLocation(err);
            }
        );
    },
    err => {
        return cb(err);
    });
}

function dumpAreaInfo(areaInfo, areaAndStorageInfo, cb) {
    console.info(`areaTag: ${areaInfo.areaTag}`);
    console.info(`name: ${areaInfo.name}`);
    console.info(`desc: ${areaInfo.desc}`);

    areaInfo.storage.forEach(si => {
        console.info(`storageTag: ${si.storageTag} => ${si.dir}`);
    });
    console.info('');

    return cb(null);
}

function getFileEntries(pattern, cb) {
    //	spec: FILENAME_WC|FILE_ID|SHA|PARTIAL_SHA
    const FileEntry = require('../../core/file_entry.js');

    async.waterfall(
        [
            function tryByFileId(callback) {
                const fileId = parseInt(pattern);
                if(!/^[0-9]+$/.test(pattern) || isNaN(fileId)) {
                    return callback(null, null);	//	try SHA
                }

                const fileEntry = new FileEntry();
                fileEntry.load(fileId, err => {
                    return callback(null, err ? null : [ fileEntry ] );
                });
            },
            function tryByShaOrPartialSha(entries, callback) {
                if(entries) {
                    return callback(null, entries);	//	already got it by FILE_ID
                }

                FileEntry.findBySha(pattern, (err, fileEntry) => {
                    return callback(null, fileEntry ? [ fileEntry ] : null );
                });
            },
            function tryByFileNameWildcard(entries, callback) {
                if(entries) {
                    return callback(null, entries);	//	already got by FILE_ID|SHA
                }

                return FileEntry.findByFileNameWildcard(pattern, callback);
            }
        ],
        (err, entries) => {
            return cb(err, entries);
        }
    );
}

function dumpFileInfo(shaOrFileId, cb) {
    async.waterfall(
        [
            function getEntry(callback) {
                getFileEntries(shaOrFileId, (err, entries) => {
                    if(err) {
                        return callback(err);
                    }

                    return callback(null, entries[0]);
                });
            },
            function dumpInfo(fileEntry, callback) {
                const fullPath = paths.join(fileArea.getAreaStorageDirectoryByTag(fileEntry.storageTag), fileEntry.fileName);

                console.info(`file_id: ${fileEntry.fileId}`);
                console.info(`sha_256: ${fileEntry.fileSha256}`);
                console.info(`area_tag: ${fileEntry.areaTag}`);
                console.info(`storage_tag: ${fileEntry.storageTag}`);
                console.info(`path: ${fullPath}`);
                console.info(`hashTags: ${Array.from(fileEntry.hashTags).join(', ')}`);
                console.info(`uploaded: ${moment(fileEntry.uploadTimestamp).format()}`);

                _.each(fileEntry.meta, (metaValue, metaName) => {
                    console.info(`${metaName}: ${metaValue}`);
                });

                if(argv['show-desc']) {
                    console.info(`${fileEntry.desc}`);
                }
                console.info('');

                return callback(null);
            }
        ],
        err => {
            return cb(err);
        }
    );
}

function displayFileAreaInfo() {
    //	AREA_TAG[@STORAGE_TAG]
    //	SHA256|PARTIAL
    //	if sha: dump file info
    //	if area/stoarge dump area(s) +

    async.series(
        [
            function init(callback) {
                return initConfigAndDatabases(callback);
            },
            function dumpInfo(callback) {
                const sysConfig = require('../../core/config.js').get();
                let suppliedAreas = argv._.slice(2);
                if(!suppliedAreas || 0 === suppliedAreas.length) {
                    suppliedAreas = _.map(sysConfig.fileBase.areas, (areaInfo, areaTag) => areaTag);
                }

                const areaAndStorageInfo = getAreaAndStorage(suppliedAreas);

                fileArea = require('../../core/file_base_area.js');

                async.eachSeries(areaAndStorageInfo, (areaAndStorage, nextArea) => {
                    const areaInfo = fileArea.getFileAreaByTag(areaAndStorage.areaTag);
                    if(areaInfo) {
                        return dumpAreaInfo(areaInfo, areaAndStorageInfo, nextArea);
                    } else {
                        return dumpFileInfo(areaAndStorage.areaTag, nextArea);
                    }
                },
                err => {
                    return callback(err);
                });
            }
        ],
        err => {
            if(err) {
                process.exitCode = ExitCodes.ERROR;
                console.error(err.message);
            }
        }
    );
}

function scanFileAreas() {
    const options = {};

    const tags = argv.tags;
    if(tags) {
        options.tags = tags.split(',');
    }

    options.descFile 	= argv['desc-file'];	//	--desc-file or --desc-file PATH
    options.quick 		= argv.quick;

    options.areaAndStorageInfo = getAreaAndStorage(argv._.slice(2));

    const last = argv._[argv._.length - 1];
    if(options.areaAndStorageInfo.length > 1 && looksLikePattern(last)) {
        options.glob = last;
        options.areaAndStorageInfo.length -= 1;
    }

    async.series(
        [
            function init(callback) {
                return initConfigAndDatabases(callback);
            },
            function initMime(callback) {
                return require('../../core/mime_util.js').startup(callback);
            },
            function initGlobalDescHandler(callback) {
                //
                //	If options.descFile is a String, it represents a FILE|PATH. We'll init
                //	the description handler now. Else, we'll attempt to look for a description
                //	file in each storage location.
                //
                if(!_.isString(options.descFile)) {
                    return callback(null);
                }

                loadDescHandler(options.descFile, (err, descHandler) => {
                    options.descFileHandler = descHandler;
                    return callback(null);
                });
            },
            function scanAreas(callback) {
                fileArea = require('../../core/file_base_area.js');

                async.eachSeries(options.areaAndStorageInfo, (areaAndStorage, nextAreaTag) => {
                    const areaInfo = fileArea.getFileAreaByTag(areaAndStorage.areaTag);
                    if(!areaInfo) {
                        return nextAreaTag(new Error(`Invalid file base area tag: ${areaAndStorage.areaTag}`));
                    }

                    console.info(`Processing area "${areaInfo.name}":`);

                    scanFileAreaForChanges(areaInfo, options, err => {
                        return callback(err);
                    });
                }, err => {
                    return callback(err);
                });
            }
        ],
        err => {
            if(err) {
                process.exitCode = ExitCodes.ERROR;
                console.error(err.message);
            }
        }
    );
}

function expandFileTargets(targets, cb) {
    let entries = [];

    //	Each entry may be PATH|FILE_ID|SHA|AREA_TAG[@STORAGE_TAG]
    const FileEntry = require('../../core/file_entry.js');

    async.eachSeries(targets, (areaAndStorage, next) => {
        const areaInfo = fileArea.getFileAreaByTag(areaAndStorage.areaTag);

        if(areaInfo) {
            //	AREA_TAG[@STORAGE_TAG] - all files in area@tag
            const findFilter = {
                areaTag : areaAndStorage.areaTag,
            };

            if(areaAndStorage.storageTag) {
                findFilter.storageTag = areaAndStorage.storageTag;
            }

            FileEntry.findFiles(findFilter, (err, fileIds) => {
                if(err) {
                    return next(err);
                }

                async.each(fileIds, (fileId, nextFileId) => {
                    const fileEntry = new FileEntry();
                    fileEntry.load(fileId, err => {
                        if(!err) {
                            entries.push(fileEntry);
                        }
                        return nextFileId(err);
                    });
                },
                err => {
                    return next(err);
                });
            });

        } else {
            //	FILENAME_WC|FILE_ID|SHA|PARTIAL_SHA
            //	:TODO: FULL_PATH -> entries
            getFileEntries(areaAndStorage.pattern, (err, fileEntries) => {
                if(err) {
                    return next(err);
                }

                entries = entries.concat(fileEntries);
                return next(null);
            });
        }
    },
    err => {
        return cb(err, entries);
    });
}

function moveFiles() {
    //
    //	oputil fb move SRC [SRC2 ...] DST
    //
    //	SRC: FILENAME_WC|FILE_ID|SHA|AREA_TAG[@STORAGE_TAG]
    //	DST: AREA_TAG[@STORAGE_TAG]
    //
    if(argv._.length < 4) {
        return printUsageAndSetExitCode(getHelpFor('FileBase'), ExitCodes.ERROR);
    }

    const moveArgs = argv._.slice(2);
    const src = getAreaAndStorage(moveArgs.slice(0, -1));
    const dst = getAreaAndStorage(moveArgs.slice(-1))[0];

    let FileEntry;

    async.waterfall(
        [
            function init(callback) {
                return initConfigAndDatabases( err => {
                    if(!err) {
                        fileArea = require('../../core/file_base_area.js');
                    }
                    return callback(err);
                });
            },
            function validateAndExpandSourceAndDest(callback) {
                const areaInfo = fileArea.getFileAreaByTag(dst.areaTag);
                if(areaInfo) {
                    dst.areaInfo = areaInfo;
                } else {
                    return callback(Errors.DoesNotExist('Invalid or unknown destination area'));
                }

                FileEntry = require('../../core/file_entry.js');

                expandFileTargets(src, (err, srcEntries) => {
                    return callback(err, srcEntries);
                });
            },
            function moveEntries(srcEntries, callback) {

                if(!dst.storageTag) {
                    dst.storageTag = dst.areaInfo.storageTags[0];
                }

                const destDir = FileEntry.getAreaStorageDirectoryByTag(dst.storageTag);

                async.eachSeries(srcEntries, (entry, nextEntry) => {
                    const srcPath 	= entry.filePath;
                    const dstPath	= paths.join(destDir, entry.fileName);

                    process.stdout.write(`Moving ${srcPath} => ${dstPath}... `);

                    FileEntry.moveEntry(entry, dst.areaTag, dst.storageTag, err => {
                        if(err) {
                            console.info(`Failed: ${err.message}`);
                        } else {
                            console.info('Done');
                        }
                        return nextEntry(null);	//	always try next
                    });
                },
                err => {
                    return callback(err);
                });
            }
        ],
        err => {
            if(err) {
                process.exitCode = ExitCodes.ERROR;
                console.error(err.message);
            }
        }
    );
}

function removeFiles() {
    //
    //	oputil fb rm|remove|del|delete SRC [SRC2 ...]
    //
    //	SRC: FILENAME_WC|FILE_ID|SHA|AREA_TAG[@STORAGE_TAG]
    //
    //	AREA_TAG[@STORAGE_TAG] remove all entries matching
    //	supplied area/storage tags
    //
    //	--phys-file removes backing physical file(s)
    //
    if(argv._.length < 3) {
        return printUsageAndSetExitCode(getHelpFor('FileBase'), ExitCodes.ERROR);
    }

    const removePhysFile = argv['phys-file'];

    const src =  getAreaAndStorage(argv._.slice(2));

    async.waterfall(
        [
            function init(callback) {
                return initConfigAndDatabases( err => {
                    if(!err) {
                        fileArea = require('../../core/file_base_area.js');
                    }
                    return callback(err);
                });
            },
            function expandSources(callback) {
                expandFileTargets(src, (err, srcEntries) => {
                    return callback(err, srcEntries);
                });
            },
            function removeEntries(srcEntries, callback) {
                const FileEntry = require('../../core/file_entry.js');

                const extraOutput = removePhysFile ? ' (including physical file)' : '';

                async.eachSeries(srcEntries, (entry, nextEntry) => {

                    process.stdout.write(`Removing ${entry.filePath}${extraOutput}... `);

                    FileEntry.removeEntry(entry, { removePhysFile }, err => {
                        if(err) {
                            console.info(`Failed: ${err.message}`);
                        } else {
                            console.info('Done');
                        }

                        return nextEntry(err);
                    });
                }, err => {
                    return callback(err);
                });
            }
        ],
        err => {
            if(err) {
                process.exitCode = ExitCodes.ERROR;
                console.error(err.message);
            }
        }
    );
}

function handleFileBaseCommand() {

    function errUsage()  {
        return printUsageAndSetExitCode(
            getHelpFor('FileBase') + getHelpFor('FileOpsInfo'),
            ExitCodes.ERROR
        );
    }

    if(true === argv.help) {
        return errUsage();
    }

    const action = argv._[1];

    return ({
        info	: displayFileAreaInfo,
        scan	: scanFileAreas,

        mv		: moveFiles,
        move	: moveFiles,

        rm		: removeFiles,
        remove	: removeFiles,
        del		: removeFiles,
        delete	: removeFiles,
    }[action] || errUsage)();
}