//
//  QueryViewController.swift
//  MongoView
//
//  Created by Shadowfacts on 1/9/20.
//  Copyright © 2020 Shadowfacts. All rights reserved.
//

import Cocoa
import MongoSwift

class QueryViewController: NSViewController {

    @IBOutlet weak var verticalSplitView: NSSplitView!
    @IBOutlet var queryTextView: NSTextView!
    @IBOutlet weak var outlineView: NSOutlineView!
    @IBOutlet weak var documentCountLabel: NSTextField!
    
    let mongoController: MongoController
    let collection: DatabaseCollection
    
    var defaultQuery: String {
        "db.getCollection('\(collection.name)').find({}).toArray()"
    }
    
    var hasQueryChanged: Bool {
        return queryTextView.string != defaultQuery
    }
    
    var mostRecentQuery: String? = nil
    
    var rootNodes: [Node] = []
    
    init(mongoController: MongoController, collection: DatabaseCollection) {
        self.mongoController = mongoController
        self.collection = collection
        
        super.init(nibName: "QueryViewController", bundle: .main)
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        refresh()

        verticalSplitView.delegate = self
        verticalSplitView.setHoldingPriority(.defaultHigh, forSubviewAt: 0)
        
        queryTextView.font = .monospacedSystemFont(ofSize: 13, weight: .regular)
        queryTextView.isAutomaticQuoteSubstitutionEnabled = false
        queryTextView.string = defaultQuery
        
        outlineView.dataSource = self
        outlineView.delegate = self
        
        outlineView.target = self
        outlineView.doubleAction = #selector(outlineCellDoubleClicked)
        
    }
    
    override func viewWillAppear() {
        super.viewWillAppear()
        
        verticalSplitView.setPosition(80, ofDividerAt: 0)

    }
    
    override func viewDidAppear() {
        super.viewDidAppear()
        
        
        view.window!.makeFirstResponder(outlineView)
    }
    
    func refresh(reload: Bool = true) {
        if let query = mostRecentQuery {
            let connStr = "\(mongoController.connectionString)/\(collection.database)"
            
            rootNodes = MongoEvaluator.eval(command: query, connectingTo: connStr).map {
                Node(value: $0)
            }
            
            title = query
            documentCountLabel.stringValue = "\(rootNodes.count) result\(rootNodes.count == 1 ? "" : "s")"
        } else {
            let documents = try! mongoController.collection(collection).find().all()
            rootNodes = documents.map { Node(document: $0) }

            title = "\(self.collection.database).\(self.collection.name)"
            documentCountLabel.stringValue = "\(documents.count) document\(documents.count == 1 ? "" : "s")"
        }
        if reload {
            outlineView.reloadData()
        }
    }
    
    func runQuery() {
        mostRecentQuery = queryTextView.string
        refresh()
    }

        rootNodes = MongoEvaluator.eval(command: query, connectingTo: connStr).map {
            Node(value: $0)
        }
        outlineView.reloadData()
    }
    
    @objc func outlineCellDoubleClicked() {
        if let item = outlineView.item(atRow: outlineView.clickedRow) {
            if outlineView.isItemExpanded(item) {
                outlineView.collapseItem(item)
            } else {
                outlineView.expandItem(item)
            }
        }
    }
    
}

extension QueryViewController: NSMenuItemValidation {
    func validateMenuItem(_ menuItem: NSMenuItem) -> Bool {
        if menuItem.action == #selector(deleteNode(_:)) {
            return outlineView.clickedRow != -1
        }
        return true
    }
}

extension QueryViewController: NSSplitViewDelegate {
    func splitView(_ splitView: NSSplitView, constrainSplitPosition proposedPosition: CGFloat, ofSubviewAt dividerIndex: Int) -> CGFloat {
        return max(80, min(splitView.bounds.height / 2, proposedPosition))
    }
}

extension QueryViewController: NSOutlineViewDataSource {
    func outlineView(_ outlineView: NSOutlineView, numberOfChildrenOfItem item: Any?) -> Int {
        if item == nil {
            return rootNodes.count
        } else if let node = item as? Node {
            return node.numberOfChildren
        } else {
            return 0
        }
    }
    
    func outlineView(_ outlineView: NSOutlineView, isItemExpandable item: Any) -> Bool {
        if let node = item as? Node {
            return node.hasChildren
        } else {
            return false
        }
    }
    
    func outlineView(_ outlineView: NSOutlineView, child index: Int, ofItem item: Any?) -> Any {
        if item == nil {
            return rootNodes[index]
        } else if let node = item as? Node {
            return node.children[index]
        } else {
            fatalError("unreachable")
        }
    }
}

extension QueryViewController: NSOutlineViewDelegate {
    func outlineView(_ outlineView: NSOutlineView, viewFor tableColumn: NSTableColumn?, item: Any) -> NSView? {
        guard let tableColumn = tableColumn,
            let node = item as? Node else {
                fatalError()
        }
        if tableColumn.identifier == .fieldNameColumn {
            let cell = outlineView.makeView(withIdentifier: .fieldNameCell, owner: nil) as! NSTableCellView
            cell.textField!.stringValue = node.keyString
            cell.textField!.isEditable = false
            return cell
        } else if tableColumn.identifier == .fieldValueColumn {
            let cell = outlineView.makeView(withIdentifier: .fieldValueCell, owner: nil) as! NSTableCellView
            cell.textField!.stringValue = node.valueString
            cell.textField!.isEditable = false
            return cell
        } else if tableColumn.identifier == .valueTypeColumn {
            let cell = outlineView.makeView(withIdentifier: .valueTypeCell, owner: nil) as! NSTableCellView
            cell.textField!.stringValue = node.typeString
            cell.textField!.isEditable = false
            return cell
        } else {
            return nil
        }
    }
}


extension NSUserInterfaceItemIdentifier {
    static let fieldNameColumn = NSUserInterfaceItemIdentifier(rawValue: "FieldNameCol")
    static let fieldValueColumn = NSUserInterfaceItemIdentifier(rawValue: "FieldValueCol")
    static let fieldNameCell = NSUserInterfaceItemIdentifier(rawValue: "FieldNameCell")
    static let fieldValueCell = NSUserInterfaceItemIdentifier(rawValue: "FieldValueCell")
    static let valueTypeColumn = NSUserInterfaceItemIdentifier(rawValue: "ValueTypeCol")
    static let valueTypeCell = NSUserInterfaceItemIdentifier(rawValue: "ValueTypeCell")
}