let db = require('@config/database')

let Tags = require('@models/Tag')
let Attachment = require('@models/Attachment')

let ProcessText = require('@helpers/ProcessText')

const DiffMatchPatch = require('@helpers/DiffMatchPatch')

var rp = require('request-promise');
const fs = require('fs')

let Note = module.exports = {}


Note.stressTest = () => {
	return new Promise((resolve, reject) => {
		db.promise()
		.query(`
		
			SELECT text FROM note;

		`)
		.then((rows, fields) => {
			console.log()

			rows[0].forEach(item => {
				
				Note.create(68, item['text'])
			})

			resolve(true)
		})
		.catch(console.log)	
	})
}

Note.create = (userId, noteText, quickNote = 0) => {
	return new Promise((resolve, reject) => {

		if(userId == null || userId < 10){ reject('User Id required to create note') }

		const created = Math.round((+new Date)/1000)

		db.promise()
		.query('INSERT INTO note (user_id, text, updated, created, quick_note) VALUES (?,?,?,?,?)', 
			[userId, noteText, created, created, quickNote])
		.then((rows, fields) => {
			// New notes are empty, don't add to solr index
			// Note.reindex(userId, rows[0].insertId)
			resolve(rows[0].insertId) //Only return the new note ID when creating a new note
		})
		.catch(console.log)
	})
}

Note.reindexAll = () => {
	return new Promise((resolve, reject) => {

		db.promise()
		.query(`
		
			SELECT id, user_id FROM note;

		`)
		.then((rows, fields) => {
			console.log()

			rows[0].forEach(item => {
				Note.reindex(item.user_id, item.id)
			})

			resolve(true)
		})
		.catch(console.log)
	})
}

Note.reindex = (userId, noteId) => {
	return new Promise((resolve, reject) => {

		Note.get(userId, noteId)
		.then(note => {
			const noteText = note.text

			//Process note text and attachment data
			Attachment.scanTextForWebsites(userId, noteId, noteText)
			.then( allNoteAttachmentText => {
				//
				// Update Solr index
				//
				Tags.string(userId, noteId)
				.then(tagString => {

					const fullText = ProcessText.removeHtml(noteText) +' '+ tagString +' '+ ProcessText.removeHtml(allNoteAttachmentText)

					db.promise()
					.query(`
					
						INSERT INTO note_text_index (note_id, user_id, text) 
						VALUES (?,?,?)
						ON DUPLICATE KEY UPDATE text = ?

					`, [noteId, userId, fullText, fullText])
					.then((rows, fields) => {
						resolve(true)
					})
					.catch(console.log)
					
				})
			})

		})
	})
}

Note.update = (userId, noteId, noteText, color, pinned, archived) => {
	return new Promise((resolve, reject) => {

		//Prevent note loss if it saves with empty text
		if(ProcessText.removeHtml(noteText) == ''){
			console.log('Not saving empty note')
			resolve(false)
		}

		const now = Math.round((+new Date)/1000)

		db.promise()
		.query('UPDATE note SET text = ?, pinned = ?, archived = ?, updated = ?, color = ? WHERE id = ? AND user_id = ? LIMIT 1', 
			[noteText, pinned, archived, now, color, noteId, userId])
		.then((rows, fields) => {

			//Async solr note reindex
			Note.reindex(userId, noteId)
			
			//Send back updated response
			resolve(rows[0])
		})
		.catch(console.log)
	})
}


//
// Delete a note and all its remaining parts
//
Note.delete = (userId, noteId) => {
	return new Promise((resolve, reject) => {

		db.promise().query('DELETE FROM note WHERE note.id = ? AND note.user_id = ?', [noteId,userId])
		.then((rows, fields) => {
			return db.promise().query('DELETE FROM note_text_index WHERE note_text_index.note_id = ? AND note_text_index.user_id = ?', [noteId,userId])	
		})
		.then((rows, fields) => {
			//Select all attachments with files
			return db.promise().query('SELECT file_location FROM attachment WHERE attachment.note_id = ? AND attachment.user_id = ?', [noteId,userId])
		})
		.then((attachmentRows, fields) => {

			//Go through each selected attachment and delete the files
			attachmentRows[0].forEach( location => {
				const fileName = location['file_location']
				if(fileName != null && fileName.length > 1){
					fs.unlink('../staticFiles/'+fileName ,function(err){ //Async, just rip through them.
						if(err) return console.log(err);
						// console.log('file deleted successfully => ', fileName);
					})
				}	
			})

			return db.promise().query('DELETE FROM attachment WHERE attachment.note_id = ? AND attachment.user_id = ?', [noteId,userId])
		})
		.then((rows, fields) => {
			return db.promise().query('DELETE FROM note_tag WHERE note_tag.note_id = ? AND note_tag.user_id = ?', [noteId,userId])	
		})
		.then((rows, fields) => {
			resolve(true)
		})
	})
}

//text is the current text for the note that will be compared to the text in the database
Note.getDiffText = (userId, noteId, usersCurrentText, lastUpdated) => {
	return new Promise((resolve, reject) => {
		Note.get(userId, noteId)
		.then(noteObject => {


			let oldText = noteObject.text.replace(/(\r\n|\n|\r)/gm,"")
			let newText = usersCurrentText.replace(/(\r\n|\n|\r)/gm,"")

			if(noteObject.updated == lastUpdated){
				// console.log('No note diff')
				resolve(null)
			}

			if(noteObject.updated > lastUpdated){
				newText = noteObject.text.replace(/(\r\n|\n|\r)/gm,"")
				oldText = usersCurrentText.replace(/(\r\n|\n|\r)/gm,"")
			}

			const dmp = new DiffMatchPatch.diff_match_patch()
			const diff = dmp.diff_main(oldText, newText)

			dmp.diff_cleanupSemantic(diff)
			const patch_list = dmp.patch_make(oldText, newText, diff);
  			const patch_text = dmp.patch_toText(patch_list);
  			
  			//Patch text -  shows a list of changes
  			var patches = dmp.patch_fromText(patch_text);
  			// console.log(patch_text)

  			//results[1] - contains diagnostic data for patch apply, its possible it can fail
  			var results = dmp.patch_apply(patches, oldText);
  			
  			//Compile return data for front end
  			const returnData = {
  				updatedText: results[0],
  				diffs: results[1].length, //Only use length for now
  				updated: Math.max(noteObject.updated,lastUpdated) //Return most recently updated date

  			}
  			
  			//Final change in notes
  			// console.log(returnData)

			resolve(returnData)
		})
	})

}

Note.get = (userId, noteId) => {
	return new Promise((resolve, reject) => {
		db.promise()
		.query(`
			SELECT note.text, note.updated, note.pinned, note.archived, note.color, count(distinct attachment.id) as attachment_count
			FROM note 
			LEFT JOIN attachment ON (note.id = attachment.note_id)
			WHERE note.user_id = ? AND note.id = ? LIMIT 1`, [userId,noteId])
		.then((rows, fields) => {

			//Return note data
			resolve(rows[0][0])

		})
		.catch(console.log)
	})
}

Note.getShared = (noteId) => {
	return new Promise((resolve, reject) => {
		db.promise()
		.query('SELECT text, updated, color FROM note WHERE id = ? AND shared = 1 LIMIT 1', [noteId])
		.then((rows, fields) => {

			//Return note data
			resolve(rows[0][0])

		})
		.catch(console.log)
	})
}

// Searches text index, returns nothing if there is no search query
Note.solrQuery = (userId, searchQuery, searchTags) => {
	return new Promise((resolve, reject) => {

		if(searchQuery.length == 0){
			resolve(null)
		} else {

			//Number of characters before and after search word
			const front = 5
			const tail = 150

			db.promise()
			.query(`
			
				SELECT 
					note_id,
					substring(
							text,
					        IF(LOCATE(?, text) > ${tail}, LOCATE(?, text) - ${front}, 1),
					        ${tail} + LENGTH(?) + ${front}
						) as snippet
				FROM note_text_index 
				WHERE user_id = ?
				AND MATCH(text)
				AGAINST(? IN NATURAL LANGUAGE MODE)
				LIMIT 1000
				;

			`, [searchQuery, searchQuery, searchQuery, userId, searchQuery])
			.then((rows, fields) => {

				let results = []
				let snippets = {}
				rows[0].forEach(item => {
					let noteId = parseInt(item['note_id'])
					//Setup array of ids to use for query
					results.push( noteId )
					//Get text snippet and highlight the key word
					snippets[noteId] = item['snippet'].replace(new RegExp(searchQuery,"ig"), '<em>'+searchQuery+'</em>');
					//.replace(searchQuery,'<em>'+searchQuery+'</em>')
				})

				resolve({ 'ids':results, 'snippets':snippets })
			})
		}

	})
}

Note.search = (userId, searchQuery, searchTags, fastFilters) => {
	return new Promise((resolve, reject) => {
		//Define return data objects
		let returnData = {
			'notes':[],
			'tags':[]
		}

		Note.solrQuery(userId, searchQuery, searchTags).then( (textSearchResults) => {

			//Pull out search results from previous query
			let textSearchIds = []
			let highlights = {}
			let returnTagResults = false

			if(textSearchResults != null){
				textSearchIds = textSearchResults['ids']
				highlights = textSearchResults['snippets']
			}

		    //No results, return empty data
			if(textSearchIds.length == 0 && searchQuery.length > 0){
				return resolve(returnData)
			}

			// Base of the query, modified with fastFilters
			// Add to query for character counts -> CHAR_LENGTH(note.text) as chars
			let noteSearchQuery = `
				SELECT note.id, 
					SUBSTRING(note.text, 1, 1500) as text, 
					updated, 
					color, 
					count(distinct note_tag.id) as tag_count, 
					count(distinct attachment.id) as attachment_count,
					note.pinned,
					note.archived
				FROM note 
				LEFT JOIN note_tag ON (note.id = note_tag.note_id)
				LEFT JOIN attachment ON (note.id = attachment.note_id)
				WHERE note.user_id = ?`
			let searchParams = [userId]

			//If text search returned results, limit search to those ids			
			if(textSearchIds.length > 0){
				searchParams.push(textSearchIds)
				noteSearchQuery += ' AND note.id IN (?)'
			}

			if(fastFilters.noteIdSet && fastFilters.noteIdSet.length > 0){
				searchParams.push(fastFilters.noteIdSet)
				noteSearchQuery += ' AND note.id IN (?)'
			}

			//If tags are passed, use those tags in search
			if(searchTags.length > 0){
				searchParams.push(searchTags)
				noteSearchQuery += ' AND note_tag.tag_id IN (?)'
			}

			//Show archived notes, only if fast filter is set, default to not archived
			if(fastFilters.onlyArchived == 1){
				noteSearchQuery += ' AND note.archived = 1' //Show Archived
			} else {
				noteSearchQuery += ' AND note.archived = 0' //Exclude archived
			}

			//Finish up note query
			noteSearchQuery += ' GROUP BY note.id'

			//Only show notes with Tags
			if(fastFilters.withTags == 1){
				returnTagResults = true
				noteSearchQuery += ' HAVING tag_count > 0'
			}
			//Only show notes with links
			if(fastFilters.withLinks == 1){
				returnTagResults = true
				noteSearchQuery += ' HAVING attachment_count > 0'
			}
			//Only show archived notes
			if(fastFilters.onlyArchived == 1){
				returnTagResults = true
				noteSearchQuery += ' HAVING note.archived = 1'
			}

			//
			// Always prioritize pinned notes in searches.

			//Default Sort, order by last updated
			let defaultOrderBy = ' ORDER BY note.pinned DESC, updated DESC, created DESC, opened DESC, id DESC'

			//Order by Last Created Date
			if(fastFilters.lastCreated == 1){
				defaultOrderBy = ' ORDER BY note.pinned DESC, created DESC, updated DESC, opened DESC, id DESC'
			}
			//Order by last Opened Date
			if(fastFilters.lastOpened == 1){
				defaultOrderBy = ' ORDER BY note.pinned DESC, opened DESC, updated DESC, created DESC, id DESC'
			}

			//Append Order by to query
			noteSearchQuery += defaultOrderBy

			
			//Manage limit params if set
			if(fastFilters.limitSize  > 0 || fastFilters.limitOffset > 0){

				const limitSize = parseInt(fastFilters.limitSize, 10) || 10 //Use int or default to 10
				const limitOffset = parseInt(fastFilters.limitOffset, 10) || 0 //Either parse int, or use zero


				// console.log(` LIMIT ${limitOffset}, ${limitSize}`)
				noteSearchQuery += ` LIMIT ${limitOffset}, ${limitSize}`
			}
			
			// console.log('------------- Final Query --------------')
			// console.log(noteSearchQuery)
			// console.log('------------- ----------- --------------')

			db.promise()
			.query(noteSearchQuery, searchParams)
			.then((noteRows, noteFields) => {

				//Push all notes
				returnData['notes'] = noteRows[0]

				//pull out all note ids so we can fetch all tags for those notes
				let noteIds = []
				returnData['notes'].forEach(note => {

					//Grab note ID for finding tags
					noteIds.push(note.id)

					if(note.text == null){ note.text = '' }

					//Deduce note title
					const textData = ProcessText.deduceNoteTitle(note.text)

					// console.log(textData)
					
					note.title = textData.title
					note.subtext = textData.sub
					note.titleLength = textData.titleLength
					note.subtextLength = textData.subtextLength

					note.note_highlights = []
					note.attachment_highlights = []
					note.tag_highlights = []

					//Push in search highlights
					if(highlights && highlights[note.id]){
						note['note_highlights'] = [highlights[note.id]]
					}

					//Clear out note.text before sending it to front end, its being used in title and subtext
					delete note.text
				})

				//If no notes are returned, there are no tags, return empty
				if(noteIds.length == 0){
					return resolve(returnData)
				}

				//Return all notes, tags are not being searched
				// if tags are being searched, continue
				// if notes are being filtered, return tags
				if(searchTags.length == 0 && returnTagResults == false){
					return resolve(returnData)
				}

				//Only show tags of selected notes
				db.promise()
				.query(`SELECT tag.id, tag.text, count(tag.id) as usages FROM note_tag
						JOIN tag ON (tag.id = note_tag.tag_id)
						WHERE note_tag.user_id = ?
						AND note_id IN (?)
						GROUP BY tag.id
						ORDER BY usages DESC;`,[userId, noteIds])
				.then((tagRows, tagFields) => {

					returnData['tags'] = tagRows[0]

					resolve(returnData)
				})
				.catch(console.log)

			})
			.catch(console.log)

		})
		.catch(console.log)
		
	})
}