//
//  Article+Database.swift
//  Database
//
//  Created by Brent Simmons on 7/3/17.
//  Copyright © 2017 Ranchero Software. All rights reserved.
//

import Foundation
import RSDatabase
import Data
import RSParser

extension Article {
	
	convenience init?(row: FMResultSet, account: Account) {
		
		guard let feedID = row.string(forColumn: DatabaseKey.feedID) else {
			return nil
		}
		guard let uniqueID = row.string(forColumn: DatabaseKey.uniqueID) else {
			return nil
		}
		
		let articleID = row.string(forColumn: DatabaseKey.articleID)!
		let title = row.string(forColumn: DatabaseKey.title)
		let contentHTML = row.string(forColumn: DatabaseKey.contentHTML)
		let contentText = row.string(forColumn: DatabaseKey.contentText)
		let url = row.string(forColumn: DatabaseKey.url)
		let externalURL = row.string(forColumn: DatabaseKey.externalURL)
		let summary = row.string(forColumn: DatabaseKey.summary)
		let imageURL = row.string(forColumn: DatabaseKey.imageURL)
		let bannerImageURL = row.string(forColumn: DatabaseKey.bannerImageURL)
		let datePublished = row.date(forColumn: DatabaseKey.datePublished)
		let dateModified = row.date(forColumn: DatabaseKey.dateModified)
		let accountInfo: [String: Any]? = nil // TODO

		// authors, tags, and attachments are fetched from related tables, after init.

		self.init(account: account, articleID: articleID, feedID: feedID, uniqueID: uniqueID, title: title, contentHTML: contentHTML, contentText: contentText, url: url, externalURL: externalURL, summary: summary, imageURL: imageURL, bannerImageURL: bannerImageURL, datePublished: datePublished, dateModified: dateModified, authors: nil, tags: nil, attachments: nil, accountInfo: accountInfo)
	}

	convenience init(parsedItem: ParsedItem, feedID: String, account: Account) {

		let authors = Author.authorsWithParsedAuthors(parsedItem.authors)
		let attachments = Attachment.attachmentsWithParsedAttachments(parsedItem.attachments)
		let tags = tagSetWithParsedTags(parsedItem.tags)

		self.init(account: account, articleID: parsedItem.syncServiceID, feedID: feedID, uniqueID: parsedItem.uniqueID, title: parsedItem.title, contentHTML: parsedItem.contentHTML, contentText: parsedItem.contentText, url: parsedItem.url, externalURL: parsedItem.externalURL, summary: parsedItem.summary, imageURL: parsedItem.imageURL, bannerImageURL: parsedItem.bannerImageURL, datePublished: parsedItem.datePublished, dateModified: parsedItem.dateModified, authors: authors, tags: tags, attachments: attachments, accountInfo: nil)
	}

	func databaseDictionary() -> NSDictionary {
		
		let d = NSMutableDictionary()
		
		d[DatabaseKey.articleID] = articleID
		d[DatabaseKey.feedID] = feedID
		d[DatabaseKey.uniqueID] = uniqueID

		d.addOptionalString(title, DatabaseKey.title)
		d.addOptionalString(contentHTML, DatabaseKey.contentHTML)
		d.addOptionalString(url, DatabaseKey.url)
		d.addOptionalString(externalURL, DatabaseKey.externalURL)
		d.addOptionalString(summary, DatabaseKey.summary)
		d.addOptionalString(imageURL, DatabaseKey.imageURL)
		d.addOptionalString(bannerImageURL, DatabaseKey.bannerImageURL)

		d.addOptionalDate(datePublished, DatabaseKey.datePublished)
		d.addOptionalDate(dateModified, DatabaseKey.dateModified)

		// TODO: accountInfo
		
		return d.copy() as! NSDictionary
	}

	// MARK: Updating with ParsedItem

	func updateTagsWithParsedTags(_ parsedTags: [String]?) -> Bool {

		// Return true if there's a change.

		let currentTags = tags

		if parsedTags == nil && currentTags == nil {
			return false
		}
		if parsedTags != nil && currentTags == nil {
			tags = Set(parsedItemTags!)
			return true
		}
		if parsedTags == nil && currentTags != nil {
			tags = nil
			return true
		}
		let parsedTagSet = Set(parsedTags!)
		if parsedTagSet == tags! {
			return false
		}
		tags = parsedTagSet
		return true
	}

	func updateAttachmentsWithParsedAttachments(_ parsedAttachments: [ParsedAttachment]?) -> Bool {

		// Return true if there's a change.

		let currentAttachments = attachments
		let updatedAttachments = Attachment.attachmentsWithParsedAttachments(parsedAttachments)

		if updatedAttachments == nil && currentAttachments == nil {
			return false
		}
		if updatedAttachments != nil && currentAttachments == nil {
			attachments = updatedAttachments
			return true
		}
		if updatedAttachments == nil && currentAttachments != nil {
			attachments = nil
			return true
		}

		guard let currentAttachments = currentAttachments, let updatedAttachments = updatedAttachments else {
			assertionFailure("currentAttachments and updatedAttachments must both be non-nil.")
			return false
		}
		if currentAttachments != updatedAttachments {
			attachments = updatedAttachments
			return true
		}
		return false
	}

	func updateAuthorsWithParsedAuthors(_ parsedAuthors: [ParsedAuthor]?) -> Bool {

		// Return true if there's a change.

		let currentAuthors = authors
		let updatedAuthors = Author.authorsWithParsedAuthors(parsedAuthors)

		if updatedAuthors == nil && currentAuthors == nil {
			return false
		}
		if updatedAuthors != nil && currentAuthors == nil {
			authors = updatedAuthors
			return true
		}
		if updatedAuthors == nil && currentAuthors != nil {
			authors = nil
			return true
		}

		guard let currentAuthors = currentAuthors, let updatedAuthors = updatedAuthors else {
			assertionFailure("currentAuthors and updatedAuthors must both be non-nil.")
			return false
		}
		if currentAuthors != updatedAuthors {
			authors = updatedAuthors
			return true
		}
		return false
	}
}

extension Article: DatabaseObject {
	
	public var databaseID: String {
		get {
			return articleID
		}
	}
}

extension Set where Element == Article {

	func articleIDs() -> Set<String> {

		return Set<String>(map { $0.databaseID })
	}

	func eachHasAStatus() -> Bool {

		for article in self {
			if article.status == nil {
				return false
			}
		}
		return true
	}

	func missingStatuses() -> Set<Article> {

		return Set<Article>(self.filter { $0.status == nil })
	}
	
	func statuses() -> Set<ArticleStatus> {
		
		return Set<ArticleStatus>(self.flatMap { $0.status })
	}

	func dictionary() -> [String: Article] {

		var d = [String: Article]()
		for article in self {
			d[article.articleID] = article
		}
		return d
	}

	func databaseObjects() -> [DatabaseObject] {

		return self.map{ $0 as DatabaseObject }
	}
}

private extension NSMutableDictionary {

	func addOptionalString(_ value: String?, _ key: String) {

		if let value = value {
			self[key] = value
		}
	}

	func addOptionalDate(_ date: Date?, _ key: String) {

		if let date = date {
			self[key] = date as NSDate
		}
	}
}