{TYPES, declare} = require './datatypes'
MAX = 65535 # (1 << 16) - 1
JSON_COLUMN_ID = 'JSON_F52E2B61-18A1-11d1-B105-00805F49916B'

class Table
	constructor: (name) ->
		if name
			{@name, @schema, @database} = Table.parseName name
			
			@path = "#{if @database then "[#{@database}]." else ""}#{if @schema then "[#{@schema}]." else ""}[#{@name}]"
			@temporary = @name.charAt(0) is '#'

		@columns = []
		@rows = []
		
		Object.defineProperty @columns, "add",
			value: (name, column, options = {}) ->
				unless column? then throw new Error "Column data type is not defined."
				if column instanceof Function then column = column()
				column.name = name
				column.nullable = options.nullable
				column.primary = options.primary
				@push column
				
		Object.defineProperty @rows, "add",
			value: (values...) ->
				@push values
	
	###
	@private
	###
	
	_makeBulk: ->
		for col in @columns
			switch col.type
				when TYPES.Xml then col.type = TYPES.NVarChar(MAX).type
				when TYPES.UDT, TYPES.Geography, TYPES.Geometry then col.type = TYPES.VarBinary(MAX).type

		@
	
	declare: ->
		pkey = @columns.filter((col) -> col.primary is true).map (col) -> col.name
		cols = @columns.map (col) ->
			def = ["[#{col.name}] #{declare col.type, col}"]
			
			if col.nullable is true
				def.push "null"
			
			else if col.nullable is false
				def.push "not null"
			
			if col.primary is true and pkey.length is 1
				def.push "primary key"
			
			def.join ' '
		
		"create table #{@path} (#{cols.join ', '}#{if pkey.length > 1 then ", constraint PK_#{if @temporary then @name.substr(1) else @name} primary key (#{pkey.join ', '})" else ""})"

	@fromRecordset: (recordset, name) ->
		t = new @ name
		
		for name, col of recordset.columns
			t.columns.add name,
				type: col.type
				length: col.length
				scale: col.scale
				precision: col.precision
			,
				nullable: col.nullable

		if t.columns.length is 1 and t.columns[0].name is JSON_COLUMN_ID
			for row in recordset
				t.rows.add JSON.stringify row
			
		else
			for row in recordset
				t.rows.add (row[col.name] for col in t.columns)...
		
		t
	
	@parseName: (name) ->
		length = name.length
		cursor = -1
		buffer = ''
		escaped = false
		path = []
		
		while ++cursor < length
			char = name.charAt cursor
			if char is '['
				if escaped
					buffer += char
				
				else
					escaped = true
			
			else if char is ']'
				if escaped
					escaped = false
				
				else
					throw new Error "Invalid table name."
			
			else if char is '.'
				if escaped
					buffer += char
				
				else
					path.push buffer
					buffer = ''
			
			else
				buffer += char
		
		if buffer
			path.push buffer
		
		switch path.length
			when 1
				name: path[0]
				schema: null
				database: null
			
			when 2
				name: path[1]
				schema: path[0]
				database: null
			
			when 3
				name: path[2]
				schema: path[1]
				database: path[0]
			
			else
				throw new Error "Invalid table name."

module.exports = Table