#!/bin/sh
# (C) 2011 by Eugeniy Mikhailov, <evgmik@gmail.com>
# vim:set ft=tcl: \
exec tclsh "$0" "$@"

package require Tcl 8.5
package require try         ;# Tcllib.
package require cmdline 1.5 ;# First version with proper error-codes.
package require json::write
package require sqlite3
package require md5
source ./GradeBook_lib.tcl

set options {
	{w          "Write to database, disabled by default"}
	{v          "Verbose"}
	{d          "Debug write DB operations"}
}
set usage "
Usage:
  $argv0 \[options] gradebook.sqlitedb blackboard.sqlitedb

  Import a foreign DB to gradebook format.
  Expect both DB files to be sqlite tables.
  Imported DB should have a single table 'export_table'

Example:
  $argv0  2020_Fall_Phys251 blackboard.db

Options:"

try {
	array set params [::cmdline::getoptions argv $options $usage]
	#parray params

	# Note: argv is modified now. The recognized options are
	# removed from it, leaving the non-option arguments behind.
	if { [llength $argv] < 2 } {
		throw {CMDLINE USAGE} [::cmdline::usage $options $usage]
	}
} trap {CMDLINE USAGE} {msg o} {
	# Trap the usage signal, print the message, and exit the application.
	# Note: Other errors are not caught and passed through to higher levels!
	puts $msg
	exit 1
}

################# Config ############################################
set categories2import [list FinalExam HomeWork LabReport]
#set categories2import [list FinalExam]

set commonInfoCol {{First Name} {Last Name} {Student ID} {Last Access} Username Availability }
set infoColumsMarkers {{ - Lateness \(H:M:S\)} { - Max Points} { - Submission Time} {Total Lateness \(H:M:S\)} {Current Weighted} {Total \[} }

set skipCreationCol [concat $commonInfoCol $infoColumsMarkers]
######################################################################

# if DRYRUN is true the database will not be modified
set DRYRUN true
set DRYRUN [expr {!$params(w)}]
if { $DRYRUN} {
	puts "DRYRUN: DB will not be modified"
}

set VERBOSE [expr {$params(v)}]
set DBDEBUG [expr {$params(d)}]

set classDB [lindex $argv 0] 
set blackboardDB [lindex $argv 1]

puts [list Categories to import: $categories2import]

sqlite3 db $classDB
sqlite3 foreignDB $blackboardDB

proc iferror { err errStat {eval_str {""} }} {
        #return; # comment out when debugging
        if { $err } {
                puts "Error: $errStat"
                if { $eval_str ne "" } {
                        puts "For query: $eval_str"
                }
        }
}

proc dbg { msg } {
	global VERBOSE
	if { $VERBOSE } {
		puts $msg
	}
}

proc dbdbg { msg } {
	global DBDEBUG
	if { $DBDEBUG } {
		puts -nonewline $msg
	}
}

proc getColListFromAnyTable {db table} {
	set all_column_names ""
	set eval_str [concat SELECT * FROM \'$table\' LIMIT 1]
	set err [catch {
		$db eval $eval_str v {
			set all_column_names $v(*)
		}
	} errStat ]
	iferror $err $errStat
	if { $err } { return false }
	return $all_column_names
}

proc getBlackboardUsernames { db } {
	set username_list {}
	set eval_str [concat SELECT Username FROM export_table]
	set err [catch {
		$db eval $eval_str v {
			lappend username_list $v(Username)
		}
	} errStat ]
	iferror $err $errStat
	if { $err } { return false }
	return $username_list
}

proc getBlackboardUserGrade { db uname col } {
	set eval_str [concat SELECT \"$col\" FROM export_table where Username=='$uname']
	set val [$db onecolumn $eval_str]
	return $val
}

proc isInList { col listCol} {
	foreach sCol $listCol {
		set result [regexp $sCol $col match]
		if { $result } {
			return true
		}
	}
	return false

}

proc trimColName { col } {
	set shortCol $col
	set category Note
	set maxScore 0
	set type Score
	set result [regexp -nocase {(.*) (\[Total Pts:.*)} $col match shortCol scoreStr]
	if { $result} {
		set result [regexp -nocase {\[Total Pts: (\d+)} $scoreStr match maxScore]
		set result [regexp -nocase {\[Total Pts: (\d+) Percentage} $scoreStr match]
		if { $result } { set type Percentage }
		set number {}
		set name $shortCol
		set result [regexp -nocase {(\D+)(\d+)} $shortCol match name number]
		set result [regexp -nocase {(\S+)\s+$} $name match name]
		switch $name {
			HW     { set name Homework ; set category HomeWork }
			Lab    { set name Lab ;      set category LabReport}
			Design { set name "Final Project Design" ; set category FinalExam }
			Report { set name "Final Project Report" ; set category FinalExam }
			Precision { set name "Final Project Precision" ; set category FinalExam }
			Hardware { set name "Final Project Hardware" ; set category FinalExam }
			"Extra Credit" { set name "Final Project Bonus" ; set category FinalExam; set maxScore 0 }
			default { }
		}
		if { $number eq "" } {
			set shortCol "$name"
		} else {
			set shortCol "$name $number"
		}
	}
	#puts [list $col "--->" $shortCol $category $maxScore $type]
	return [list $shortCol $category $maxScore $type]
}

proc dbRequest {script} { 
	# verbose evaluation of dbRequest with dry run capability
	global DRYRUN
	set cmd ""
	foreach line [split $script \n] {
		if {$line eq ""} {continue}
		append cmd $line\n
		if { [info complete $cmd] } {
			if { ![info exists DRYRUN] || $DRYRUN} {
				dbdbg "DRYRUN: $cmd"
			} else {
				dbdbg "EXECUTING: $cmd"
				uplevel 1 $cmd
			}
			set cmd ""
		}
	}
}

## adding students if they do not exist
proc addStudentsFromBlackboardDB { db } {
	# blackboard does not provide the following info
	set id unknownID
	set section unknownSection
	puts "Blackboard does not provide Student ID and Section number, skipping user addition"
	#return

	set fname [list First Name]
	set lname [list Last Name]
	set eval_str [concat SELECT * FROM 'export_table']
	set err [catch {
		$db eval $eval_str v {
			set username [blackboardUsername2local $v(Username)]
			dbRequest [list AddUserNonWeb $v($fname) $v($lname) $username student $id $section]
			}
		} errStat ]
	iferror $err $errStat
}

proc blackboardUsername2local { uname } {
	return "$uname@email.wm.edu"
}

proc updateGrade { col locUname grade } {
	set oldGrade [SelectColValue4User $col $locUname ]
	#puts "$locUname: $col oldGrade \{$oldGrade\} --> \{$grade\}"
	if { $oldGrade == $grade } { return }
	if { [regexp -nocase -- {excuse} $oldGrade] } {
		# remote system do not handle excuses
		# so local system take precedence
		dbg [list "not updating \"excused\" grade:" $locUname  $col $oldGrade "-->" $grade]
		return
	}
	if { $oldGrade != $grade } {
		#puts "$locUname: $col oldGrade \{$oldGrade\} --> \{$grade\}"
		puts [list $locUname  $col $oldGrade "-->" $grade]
		dbRequest [list UpdateColValue4UserNameNonWeb $col $locUname $grade]
	}
}

proc pickCols2import { cols2import skipCreationCol categories2import } {
	set reduced_list {}
	foreach col $cols2import {
		if { [isInList $col $skipCreationCol] } {
			dbg "skipping column $col"
			continue
		}
		set colInfo  [trimColName $col]
		set category [lindex $colInfo 1]
		if { $category ni $categories2import } {
			dbg [list skipping $col in $category, permitted categories: $categories2import]
			continue
		}
		lappend reduced_list $col
	}
	return $reduced_list
}

proc normilizeBlackboardGrade { grade colInfo } {
	set shortCol [lindex $colInfo 0]
	set category [lindex $colInfo 1]
	set maxScore [lindex $colInfo 2]
	set scoreType [lindex $colInfo 3]
	if { "" ne $grade } {
		if { $scoreType eq "Percentage" } {
			# change percentage to score
			set grade [ expr {$grade/100*$maxScore} ]
		}
	}
	return $grade
}

proc alias {alias target} {
    # makes alias to a proc, borrowed from
    # https://wiki.tcl-lang.org/page/proc+alias
    set fulltarget [uplevel [list namespace which $target]]
    if {$fulltarget eq {}} {
        return -code error [list {no such command} $target]
    }
    set save [namespace eval [namespace qualifiers $fulltarget] {
        namespace export}]
    namespace eval [namespace qualifiers $fulltarget] {namespace export *}
    while {[namespace exists [
        set tmpns [namespace current]::[info cmdcount]]]} {}
    set code [catch {set newcmd [namespace eval $tmpns [
        string map [list @{fulltarget} [list $fulltarget]] {
        namespace import @{fulltarget}
    }]]} cres copts]
    namespace eval [namespace qualifiers $fulltarget] [
        list namespace export {*}$save]
    if {$code} {
        return -options $copts $cres
    }
    uplevel [list rename ${tmpns}::[namespace tail $target] $alias]
    namespace delete $tmpns 
    return [uplevel [list namespace which $alias]]
}

######################### START of the execution #########################

alias foreignUsername2local      blackboardUsername2local
alias addStudentsFromForeignDB   addStudentsFromBlackboardDB
alias getForeignDBUsernames      getBlackboardUsernames
alias getForeignDBUserGrade      getBlackboardUserGrade
alias normilizeGrade             normilizeBlackboardGrade

addStudentsFromForeignDB foreignDB

# now for every user add their grades
set username_list [getForeignDBUsernames foreignDB]
set cols2import [getColListFromAnyTable foreignDB export_table]

set cols2import [ pickCols2import $cols2import $skipCreationCol $categories2import]

foreach col $cols2import {
	set colInfo  [trimColName $col]
	set shortCol [lindex $colInfo 0]
	if { ![doesColumnExists $shortCol GradesTable] } {
		dbRequest [list AddColumnNonWeb $shortCol $category $maxScore]
	}
	foreach uname $username_list {
		set locUname [foreignUsername2local $uname]
		set grade [getForeignDBUserGrade foreignDB $uname $col ]
		set grade [normilizeGrade $grade $colInfo]
		updateGrade $shortCol $locUname $grade
	}
}