--[[
	ProFi v1.3, by Luke Perkin 2012. MIT Licence http://www.opensource.org/licenses/mit-license.php.
	
	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. Get the most recent version at this gist: https://gist.github.com/2838755
###############################################################################################################

]]

-----------------------
-- 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(interval, note)
    local time = getTime()
    interval = interval 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))
    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
    local line        = string.format(FORMAT_LINENUM, linedefined)
    return string.format(FORMAT_TITLE, source, name, line)
end

function ProFi:createFuncReport(funcInfo)
    local name = funcInfo.name or 'anonymous'
    local source = funcInfo.source or 'C Func'
    local linedefined = funcInfo.linedefined or 0
    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 i, 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 i, 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 i, 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 k, inspection in pairs(inspections) do
        inspectionsList[#inspectionsList + 1] = inspection
    end
    table.sort(inspectionsList, sortByCallCount)
    return inspectionsList
end

function ProFi:resetReports(reports)
    for i, 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()
object:export(ProFi, "ProFi")