--[[
ProFi v1.3, by Luke Perkin 2012. MIT Licence http://www.opensource.org/licenses/mit-license.php.
Updated to v1.4 by Robert Machmer 2017

    Example:
        ProFi = require 'ProFi'
        ProFi:start()
        some_function()
        another_function()
        coroutine.resume( some_coroutine )
        ProFi:stop()
        ProFi:writeReport( 'MyProfilingReport.txt' )

    API:
    *Arguments are specified as: type/name/default.
        ProFi:start( string/once/nil )
        ProFi:stop()
        ProFi:checkMemory( number/interval/0, string/note/'' )
        ProFi:writeReport( string/filename/'ProFi.txt' )
        ProFi:reset()
        ProFi:setHookCount( number/hookCount/0 )
        ProFi:setGetTimeMethod( function/getTimeMethod/os.clock )
        ProFi:setInspect( string/methodName, number/levels/1 )
]]

-----------------------
-- Locals:
-----------------------

local ProFi = {}
local onDebugHook, sortByDurationDesc, sortByCallCount, getTime
local DEFAULT_DEBUG_HOOK_COUNT = 0
local FORMAT_HEADER_LINE       = "| %-50s: %-40s: %-20s: %-12s: %-12s: %-12s|\n"
local FORMAT_OUTPUT_LINE       = "| %s: %-12s: %-12s: %-12s|\n"
local FORMAT_INSPECTION_LINE   = "> %s: %-12s\n"
local FORMAT_TOTALTIME_LINE    = "| TOTAL TIME = %f\n"
local FORMAT_MEMORY_LINE       = "| %-20s: %-16s: %-16s| %s\n"
local FORMAT_HIGH_MEMORY_LINE  = "H %-20s: %-16s: %-16sH %s\n"
local FORMAT_LOW_MEMORY_LINE   = "L %-20s: %-16s: %-16sL %s\n"
local FORMAT_TITLE             = "%-50.50s: %-40.40s: %-20s"
local FORMAT_LINENUM           = "%4i"
local FORMAT_TIME              = "%04.3f"
local FORMAT_RELATIVE          = "%03.2f%%"
local FORMAT_COUNT             = "%7i"
local FORMAT_KBYTES            = "%7i Kbytes"
local FORMAT_MBYTES            = "%7.1f Mbytes"
local FORMAT_MEMORY_HEADER1    = "\n=== HIGH & LOW MEMORY USAGE ===============================\n"
local FORMAT_MEMORY_HEADER2    = "=== MEMORY USAGE ==========================================\n"
local FORMAT_BANNER            = [[
###############################################################################################################
#####  ProFi, a lua profiler. This profile was generated on: %s
#####  ProFi is created by Luke Perkin 2012 under the MIT Licence, www.locofilm.co.uk
#####  Version 1.3 Original gist can be found at https://gist.github.com/perky/2838755
#####  Version 1.4 Cleaned up code to work with luacheck https://gist.github.com/rm-code/383c98a6af04652ed9f39b7ae536bcc5
###############################################################################################################


]]

-----------------------
-- Public Methods:
-----------------------

--[[
Starts profiling any method that is called between this and ProFi:stop().
Pass the parameter 'once' to so that this methodis only run once.
Example:
ProFi:start( 'once' )
]]
function ProFi:start( param )
    if param == 'once' then
        if self:shouldReturn() then
            return
        else
            self.should_run_once = true
        end
    end
    self.has_started  = true
    self.has_finished = false
    self:resetReports( self.reports )
    self:startHooks()
    self.startTime = getTime()
end

--[[
Stops profiling.
]]
function ProFi:stop()
    if self:shouldReturn() then
        return
    end
    self.stopTime = getTime()
    self:stopHooks()
    self.has_finished = true
end

function ProFi:checkMemory( ninterval, note )
    local time = getTime()
    local interval = ninterval or 0
    if self.lastCheckMemoryTime and time < self.lastCheckMemoryTime + interval then
        return
    end
    self.lastCheckMemoryTime = time
    local memoryReport = {
        ['time']   = time;
        ['memory'] = collectgarbage('count');
        ['note']   = note or '';
    }
    table.insert( self.memoryReports, memoryReport )
    self:setHighestMemoryReport( memoryReport )
    self:setLowestMemoryReport( memoryReport )
end

--[[
Writes the profile report to a file.
Param: [filename:string:optional] defaults to 'ProFi.txt' if not specified.
]]
function ProFi:writeReport( filename )
    if #self.reports > 0 or #self.memoryReports > 0 then
        filename = filename or 'ProFi.txt'
        self:sortReportsWithSortMethod( self.reports, self.sortMethod )
        self:writeReportsToFilename( filename )
        print( string.format("[ProFi]\t Report written to %s", filename) )
        return true;
    end
end

--[[
Resets any profile information stored.
]]
function ProFi:reset()
    self.reports = {}
    self.reportsByTitle = {}
    self.memoryReports  = {}
    self.highestMemoryReport = nil
    self.lowestMemoryReport  = nil
    self.has_started  = false
    self.has_finished = false
    self.should_run_once = false
    self.lastCheckMemoryTime = nil
    self.hookCount = self.hookCount or DEFAULT_DEBUG_HOOK_COUNT
    self.sortMethod = self.sortMethod or sortByDurationDesc
    self.inspect = nil
end

--[[
Set how often a hook is called.
See http://pgl.yoyo.org/luai/i/debug.sethook for information.
Param: [hookCount:number] if 0 ProFi counts every time a function is called.
if 2 ProFi counts every other 2 function calls.
]]
function ProFi:setHookCount( hookCount )
    self.hookCount = hookCount
end

--[[
Set how the report is sorted when written to file.
Param: [sortType:string] either 'duration' or 'count'.
'duration' sorts by the time a method took to run.
'count' sorts by the number of times a method was called.
]]
function ProFi:setSortMethod( sortType )
    if sortType == 'duration' then
        self.sortMethod = sortByDurationDesc
    elseif sortType == 'count' then
        self.sortMethod = sortByCallCount
    end
end

--[[
By default the getTime method is os.clock (CPU time),
If you wish to use other time methods pass it to this function.
Param: [getTimeMethod:function]
]]
function ProFi:setGetTimeMethod( getTimeMethod )
    getTime = getTimeMethod
end

--[[
Allows you to inspect a specific method.
Will write to the report a list of methods that
call this method you're inspecting, you can optionally
provide a levels parameter to traceback a number of levels.
Params: [methodName:string] the name of the method you wish to inspect.
[levels:number:optional] the amount of levels you wish to traceback, defaults to 1.
]]
function ProFi:setInspect( methodName, levels )
    if self.inspect then
        self.inspect.methodName = methodName
        self.inspect.levels = levels or 1
    else
        self.inspect = {
            ['methodName'] = methodName;
            ['levels'] = levels or 1;
        }
    end
end

-----------------------
-- Implementations methods:
-----------------------

function ProFi:shouldReturn( )
    return self.should_run_once and self.has_finished
end

function ProFi:getFuncReport( funcInfo )
    local title = self:getTitleFromFuncInfo( funcInfo )
    local funcReport = self.reportsByTitle[ title ]
    if not funcReport then
        funcReport = self:createFuncReport( funcInfo )
        self.reportsByTitle[ title ] = funcReport
        table.insert( self.reports, funcReport )
    end
    return funcReport
end

function ProFi:getTitleFromFuncInfo( funcInfo )
    local name        = funcInfo.name or 'anonymous'
    local source      = funcInfo.short_src or 'C_FUNC'
    local linedefined = funcInfo.linedefined or 0
    linedefined = string.format( FORMAT_LINENUM, linedefined )
    return string.format(FORMAT_TITLE, source, name, linedefined)
end

function ProFi:createFuncReport( funcInfo )
    local funcReport = {
        ['title']         = self:getTitleFromFuncInfo( funcInfo );
        ['count'] = 0;
        ['timer']         = 0;
    }
    return funcReport
end

function ProFi:startHooks()
    debug.sethook( onDebugHook, 'cr', self.hookCount )
end

function ProFi:stopHooks()
    debug.sethook()
end

function ProFi:sortReportsWithSortMethod( reports, sortMethod )
    if reports then
        table.sort( reports, sortMethod )
    end
end

function ProFi:writeReportsToFilename( filename )
    local file, err = io.open( filename, 'w' )
    assert( file, err )
    self:writeBannerToFile( file )
    if #self.reports > 0 then
        self:writeProfilingReportsToFile( self.reports, file )
    end
    if #self.memoryReports > 0 then
        self:writeMemoryReportsToFile( self.memoryReports, file )
    end
    file:close()
end

function ProFi:writeProfilingReportsToFile( reports, file )
    local totalTime = self.stopTime - self.startTime
    local totalTimeOutput =  string.format(FORMAT_TOTALTIME_LINE, totalTime)
    file:write( totalTimeOutput )
    local header = string.format( FORMAT_HEADER_LINE, "FILE", "FUNCTION", "LINE", "TIME", "RELATIVE", "CALLED" )
    file:write( header )
    for _, funcReport in ipairs( reports ) do
        local timer         = string.format(FORMAT_TIME, funcReport.timer)
        local count         = string.format(FORMAT_COUNT, funcReport.count)
        local relTime         = string.format(FORMAT_RELATIVE, (funcReport.timer / totalTime) * 100 )
        local outputLine    = string.format(FORMAT_OUTPUT_LINE, funcReport.title, timer, relTime, count )
        file:write( outputLine )
        if funcReport.inspections then
            self:writeInpsectionsToFile( funcReport.inspections, file )
        end
    end
end

function ProFi:writeMemoryReportsToFile( reports, file )
    file:write( FORMAT_MEMORY_HEADER1 )
    self:writeHighestMemoryReportToFile( file )
    self:writeLowestMemoryReportToFile( file )
    file:write( FORMAT_MEMORY_HEADER2 )
    for _, memoryReport in ipairs( reports ) do
        local outputLine = self:formatMemoryReportWithFormatter( memoryReport, FORMAT_MEMORY_LINE )
        file:write( outputLine )
    end
end

function ProFi:writeHighestMemoryReportToFile( file )
    local memoryReport = self.highestMemoryReport
    local outputLine   = self:formatMemoryReportWithFormatter( memoryReport, FORMAT_HIGH_MEMORY_LINE )
    file:write( outputLine )
end

function ProFi:writeLowestMemoryReportToFile( file )
    local memoryReport = self.lowestMemoryReport
    local outputLine   = self:formatMemoryReportWithFormatter( memoryReport, FORMAT_LOW_MEMORY_LINE )
    file:write( outputLine )
end

function ProFi:formatMemoryReportWithFormatter( memoryReport, formatter )
    local time       = string.format(FORMAT_TIME, memoryReport.time)
    local kbytes     = string.format(FORMAT_KBYTES, memoryReport.memory)
    local mbytes     = string.format(FORMAT_MBYTES, memoryReport.memory/1024)
    local outputLine = string.format(formatter, time, kbytes, mbytes, memoryReport.note)
    return outputLine
end

function ProFi:writeBannerToFile( file )
    local banner = string.format(FORMAT_BANNER, os.date())
    file:write( banner )
end

function ProFi:writeInpsectionsToFile( inspections, file )
    local inspectionsList = self:sortInspectionsIntoList( inspections )
    file:write('\n==^ INSPECT ^======================================================================================================== COUNT ===\n')
    for _, inspection in ipairs( inspectionsList ) do
        local line             = string.format(FORMAT_LINENUM, inspection.line)
        local title         = string.format(FORMAT_TITLE, inspection.source, inspection.name, line)
        local count         = string.format(FORMAT_COUNT, inspection.count)
        local outputLine    = string.format(FORMAT_INSPECTION_LINE, title, count )
        file:write( outputLine )
    end
    file:write('===============================================================================================================================\n\n')
end

function ProFi:sortInspectionsIntoList( inspections )
    local inspectionsList = {}
    for _, inspection in pairs(inspections) do
        inspectionsList[#inspectionsList+1] = inspection
    end
    table.sort( inspectionsList, sortByCallCount )
    return inspectionsList
end

function ProFi:resetReports( reports )
    for _, report in ipairs( reports ) do
        report.timer = 0
        report.count = 0
        report.inspections = nil
    end
end

function ProFi:shouldInspect( funcInfo )
    return self.inspect and self.inspect.methodName == funcInfo.name
end

function ProFi:getInspectionsFromReport( funcReport )
    local inspections = funcReport.inspections
    if not inspections then
        inspections = {}
        funcReport.inspections = inspections
    end
    return inspections
end

function ProFi:getInspectionWithKeyFromInspections( key, inspections )
    local inspection = inspections[key]
    if not inspection then
        inspection = {
            ['count']  = 0;
        }
        inspections[key] = inspection
    end
    return inspection
end

function ProFi:doInspection( inspect, funcReport )
    local inspections = self:getInspectionsFromReport( funcReport )
    local levels = 5 + inspect.levels
    local currentLevel = 5
    while currentLevel < levels do
        local funcInfo = debug.getinfo( currentLevel, 'nS' )
        if funcInfo then
            local source = funcInfo.short_src or '[C]'
            local name = funcInfo.name or 'anonymous'
            local line = funcInfo.linedefined
            local key = source..name..line
            local inspection = self:getInspectionWithKeyFromInspections( key, inspections )
            inspection.source = source
            inspection.name = name
            inspection.line = line
            inspection.count = inspection.count + 1
            currentLevel = currentLevel + 1
        else
            break
        end
    end
end

function ProFi:onFunctionCall( funcInfo )
    local funcReport = ProFi:getFuncReport( funcInfo )
    funcReport.callTime = getTime()
    funcReport.count = funcReport.count + 1
    if self:shouldInspect( funcInfo ) then
        self:doInspection( self.inspect, funcReport )
    end
end

function ProFi:onFunctionReturn( funcInfo )
    local funcReport = ProFi:getFuncReport( funcInfo )
    if funcReport.callTime then
        funcReport.timer = funcReport.timer + (getTime() - funcReport.callTime)
    end
end

function ProFi:setHighestMemoryReport( memoryReport )
    if not self.highestMemoryReport then
        self.highestMemoryReport = memoryReport
    else
        if memoryReport.memory > self.highestMemoryReport.memory then
            self.highestMemoryReport = memoryReport
        end
    end
end

function ProFi:setLowestMemoryReport( memoryReport )
    if not self.lowestMemoryReport then
        self.lowestMemoryReport = memoryReport
    else
        if memoryReport.memory < self.lowestMemoryReport.memory then
            self.lowestMemoryReport = memoryReport
        end
    end
end

-----------------------
-- Local Functions:
-----------------------

getTime = os.clock

onDebugHook = function( hookType )
    local funcInfo = debug.getinfo( 2, 'nS' )
    if hookType == "call" then
        ProFi:onFunctionCall( funcInfo )
    elseif hookType == "return" then
        ProFi:onFunctionReturn( funcInfo )
    end
end

sortByDurationDesc = function( a, b )
    return a.timer > b.timer
end

sortByCallCount = function( a, b )
    return a.count > b.count
end

-----------------------
-- Return Module:
-----------------------

ProFi:reset()
return ProFi