var dbFile = "/usr/db/data.db"
// app.get('/json/add/:tag',               fns.addTag);               // Adds a tag to the scan list
// app.get('/json/remove/:tag',            fns.removeTag);            // Removes a tag from the scan list
// app.get('/json/val/:tag',               fns.latestTagValue);       // Gets the latest value of a single tag
// app.get('/json/series/:tag/:hours',     fns.seriesTagValues);      // Gets all the values of a tag for the last X hours
// app.get('/json/tags',                   fns.allTags);              // Lists all tags in the scan list
// app.get('/json/all',                    fns.allValues);            // Gets the latest values of all tags in the scan list


var getTagID = function(tagName, cb){
	//Returns function(err, id)
	var sqlite3 = require('sqlite3').verbose();
	var db = new sqlite3.Database(dbFile);

	db.serialize(function(){
		var query = "SELECT id FROM tags WHERE tagName = ?";
		var prepQuery = db.prepare(query);
		prepQuery.all(tagName, function(err, rows){
			prepQuery.finalize();
			db.close();
			if (err){
				cb(err, null);
			} else {
				cb(null, rows[0].id);
			}
		})
	});
};

var getTagName = function(tagID, cb){
	//Returns function(err, tagName)
	var sqlite3 = require('sqlite3').verbose();
	var db = new sqlite3.Database(dbFile);

	db.serialize(function(){
		var query = "SELECT tagName FROM tags WHERE id = ?";
		var prepQuery = db.prepare(query);
		prepQuery.all(tagID, function(err, rows){
			prepQuery.finalize();
			db.close();
			if (err){
				cb(err, null);
			} else {
				cb(null, rows[0].tagName);
			}
		})
	});
};

exports.getTagID = function(req, res){
	getTagID(req.params.tagName, function(err, id){
		if (err){
			console.log(err);
			res.json({status:"error", message:err});
		} else {
			res.json({status: "OK", tagName: req.params.tagName, id: id});
		}
	})
};

exports.getTagName = function(req, res){
	getTagName(req.params.tagID, function(err, tagName){
		if (err){
			console.log(err);
			res.json({status:"error", message:err});
		} else {
			res.json({status: "OK", tagID: req.params.tagID, tagName: tagName});
		}
	})
};

exports.addTag = function(req, res){
	var sqlite3 = require('sqlite3').verbose();
	var db = new sqlite3.Database(dbFile);

	db.serialize(function(){
		var query = "INSERT INTO tags (tagName, units) VALUES (?, ?)";
		var prepQuery = db.prepare(query);
		prepQuery.run(req.params.tagName, req.params.units, function(err){
			prepQuery.finalize();
			db.close();
			if (err) {
			  	res.json({status:"error", message:err});
			  	console.log(err);
			} else {
				res.json({status:"OK"});
			}
		});
	});
};

exports.removeTag = function(req, res){
	var sqlite3 = require('sqlite3').verbose();
	var db = new sqlite3.Database(dbFile);

	db.serialize(function(){
		var query = "UPDATE tags SET deleted = 1 WHERE id = ?";
		var preqQuery = db.prepare(query);
		prepQuery.run(req.params.tag, function(err) {
			prepQuery.finalize();
			db.close();
			if (err) {
			  	res.json({status:"error", message:err});
			  	console.log(err);
			} else {
				res.json({status:"OK"});
			}
		});
	});
};

exports.latestTagValue = function(req, res){
	var sqlite3 = require('sqlite3').verbose();
	var db = new sqlite3.Database(dbFile);

	db.serialize(function(){
		var query = "SELECT * FROM vals WHERE id = (SELECT MAX(id) FROM vals WHERE tagID = (SELECT id FROM tags WHERE tagName = ?))";
		var prepQuery = db.prepare(query);
		prepQuery.run(req.params.tag, function(err) {
			prepQuery.finalize();
			db.close();
			if (err) {
			  	res.json({status:"error", message:err});
			  	console.log(err);
			} else {
				res.json({status:"OK", tag_val:rows[0]});
			}
		});
	});
};

exports.seriesTagValues = function(req, res){
	var sqlite3 = require('sqlite3').verbose();
	var db = new sqlite3.Database(dbFile);

	db.serialize(function(){
		var query = "SELECT * FROM vals WHERE tagID = ? AND dateAdded > DATETIME('now', '-? HOUR')";
		var prepQuery = db.prepare(query);
		prepQuery.all(parseInt(req.params.tag), parseInt(req.params.hours), function(err, rows){
			prepQuery.finalize();
			db.close();
			if (err){
				console.log(err);
				res.json({status:"error", message:err, query:query});
			} else {
				res.json({status:"OK", tag: req.params.tag, vals:rows});
			}
		})
	});
};

exports.allTags = function(req, res){
	var sqlite3 = require('sqlite3').verbose();
	var db = new sqlite3.Database(dbFile);

	db.serialize(function(){
		var query = "SELECT * FROM tags WHERE deleted = 0";
		var prepQuery = db.prepare(query);
		prepQuery.all(function(err, rows) {
			prepQuery.finalize();
			db.close();
			if (err) {
			  	res.json({status:"error", message:err});
			  	console.log(err);
			} else {
				res.json({status:"OK", tags:rows});
			}
		});
	});
};

exports.allValues = function(req, res){
	res.json({status: "error", message: "not implemented"});
};