' Gambas module file

'''
' Name: ModuleDatabase
' Author: Timothy Marshal-Nichols
' eMail: timothy.marshal-nichols@ntlworld.com
' Version: 1.0
' Version Date: April 2007
' Version History:
'
'''
' Licence Information
'
' This program is free software; you can redistribute it and/or modify
' it under the terms of the GNU General Public License as published by
' the Free Software Foundation; either version 2 of the License, or
' (at your option) any later version.
'
' This program is distributed in the hope that it will be useful,
' but WITHOUT ANY WARRANTY; without even the implied warranty of
' MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
' GNU General Public License for more details.
'
' You should have received a copy of the GNU General Public License
' along with this program; if not, write to the Free Software
' Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
'
' http://www.gnu.org/licenses/gpl.html
'
'''
' Description:
'
' Provides the interface to the pictures database.
'
'''
' Developed using Gambas2 Version
'
'  Version: 1.9.48
'
' Gambas Components Used:
'
' gb - Gambas internal native classes
' gb.db - Database access
'
' Look in the Project menu then Properties... and select
' the Components tab. Check that the listed components
' are in the project.
'
'''
' External Dependencies:
'
' The required type of database must exist.
'
'''
' Class Usage:
'
'   Open the pictures database. If the database or table does not
'   exist then they are created.
'
'   Use somthing like this for a SQLite3 database
'
'     ModuleDatabase.OpenDatabase("sqlite3", User.Home, Application.Name, "", "")
'
'   Use somthing like this for a MySQL database
'
'     ModuleDatabase.OpenDatabase("mysql", "localhost", Application.Name, "mysql", "password")
'
'   Use somthing like this for a PostgreSQL database
'
'     ModuleDatabase.OpenDatabase("postgresql", "localhost", Application.Name, "timothy", "password")
'
'   Call the Select() method to update items and then use ResultPictures to access the data.
'
'     ModuleDatabase.Select()
'     ModuleDatabase.ResultPictures.MoveTo(Row)
'
'   You can then use the Add(), Update() and Delete() methods to change the database.
'
'     ModuleDatabase.Add(Path) 
'     ModuleDatabase.Update(Row, NewDescription)
'     ModuleDatabase.Delete(Row)
'
'   Call the CloseDatabase method before you quit your application
'
'      ModuleDatabase.CloseDatabase()
'
'''

Public Const ThumbSize As Integer = 36
Public ResultPictures As Result

Private databaseConnection As New Connection
Private tempFile As String

Public Sub _init()
  tempFile = Temp() & ".png"
End

' Opens the pictures database. If the database or table does not
' exist then they are created.
Public Sub OpenDatabase(DBType As String, DBHost As String, DBName As String, UserName As String, UserPassword As String)
  Dim pictureTable As Table
  Dim errorMessageHeader As String
  ' If you wnat to see the commands sent to the
  ' database then uncommant this line
  ' DB.Debug = TRUE
  ' DBName = Lower(DBName)
  ' Open a connection (to the database server only)
  databaseConnection.Type = Lower(DBType)
  databaseConnection.Host = DBHost
  databaseConnection.Name = ""
  databaseConnection.Login = UserName
  databaseConnection.Password = UserPassword
  databaseConnection.Port = ""
  ' Open the connection
  Try databaseConnection.Open()
  If Error Then
    errorMessageHeader = ("Could not open database connection") & " " & DBHost
    Error.Raise(Error.Text)
  End If
  ' Check if the server connection has a database with the
  ' required database name.
  If Not databaseConnection.Databases.Exist(DBName) Then
    Print ("Database not found. Creating new database")
    ' Create a new database
    databaseConnection.Databases.Add(DBName)
    ' I found I needed this with a SQLite database
    ' (but not with a MySQL database)
    Wait 0.5
  End If
  ' Close the server connection
  databaseConnection.Close()
  ' Open a connection to the database
  databaseConnection.Host = DBHost
  databaseConnection.Name = DBName
  Try databaseConnection.Open()
  If Error Then
    errorMessageHeader = ("Could not open database") & " " & DBName & " on " & DBHost
    Error.Raise(Error.Text)
  End If
  ' Check if the database has a pictures table
  If Not databaseConnection.Tables.Exist("pictures") Then
    Print ("Database tables not found. Creating new pictures table")
    ' Add a picture table to the database
    pictureTable = databaseConnection.Tables.Add("pictures")
    pictureTable.Fields.Add("id", db.Serial) '             id          field as autoinc integer
    pictureTable.Fields.Add("thumb", db.Blob) '            thumb       field as blob
    pictureTable.Fields.Add("image", db.Blob) '          ' image       field as blob
    pictureTable.Fields.Add("description", db.String, 0) ' description field as unlimited string
    pictureTable.PrimaryKey = ["id"]
    pictureTable.Update()
  End If
Catch
  If errorMessageHeader = "" Then
    errorMessageHeader = ("Database connection error:") & " " & DBName & " on " & DBHost
  End If
  Error.Raise("" & errorMessageHeader & "
" & ("Error:") & "
" & DConv(Error.Text))
End

Public Sub Add(ImagePath As String)
  Dim img As Image
  Dim newPicture As Result
  'Dim pictureData As String
  Dim scale As Float
  Dim eTime As Float
  newPicture = databaseConnection.Create("pictures")
  ' Save temp image as png file
  img = Image.Load(ImagePath)
  img.Save(tempFile)
  newPicture["image"] = File.Load(tempFile)
  ' Create image thumb
  If img.Width > thumbSize Or img.Height > thumbSize Then 
    ' Calc factor to scale isotropic
    scale = Min(ThumbSize / img.Width, ThumbSize / img.Height)
    img = img.Stretch(img.Width * scale, img.Height * scale)
    img.Save(tempFile)
  End If
  newPicture["thumb"] = File.Load(tempFile)
  ' Add description and update
  newPicture["description"] = ("Image") & " " & File.BaseName(ImagePath) & " " & ("added:") & " " & Format(Now, "dddd, dd mmmm yyyy hh:nn:ss")
  eTime = Timer
  newPicture.Update()
  Print ("Done in") & " "; Format(Timer - eTime, "#.###"); " " & ("s")
  If Exist(tempFile) Then Kill tempFile
Catch
  Error.Raise(("Add database record error
Error:
") & DConv(Error.Text))
End

Public Sub Select()
  ResultPictures = databaseConnection.Edit("pictures")
Catch
  Error.Raise(("Select database records error
Error:
") & DConv(Error.Text))
End

Public Sub Update(Row As Integer, Description As String)
  ResultPictures.MoveTo(Row)
  ResultPictures["description"] = Conv(Description, Desktop.Charset, databaseConnection.Charset)
  ResultPictures.Update()
Catch
  Error.Raise(("Update database record error
Error:
") & DConv(Error.Text))
End

Public Sub Delete(Row As Integer)
  ResultPictures.MoveTo(Row)
  ResultPictures.Delete()
Catch
  Error.Raise(("Delete database record error
Error:
") & DConv(Error.Text))
End

Public Sub CloseDatabase()
  Try databaseConnection.Close()
  If Error Then Print ("Error closing database")
End

''' End of ModuleDatabase '''
