local subprocess = require 'bee.subprocess'
local method     = require 'method'
local thread     = require 'bee.thread'
local async      = require 'async'
local rpc        = require 'rpc'
local parser     = require 'parser'
local core       = require 'core'
local lang       = require 'language'
local updateTimer= require 'timer'
local buildVM    = require 'vm'
local sourceMgr  = require 'vm.source'
local localMgr   = require 'vm.local'
local valueMgr   = require 'vm.value'
local chainMgr   = require 'vm.chain'
local functionMgr= require 'vm.function'
local listMgr    = require 'vm.list'
local emmyMgr    = require 'emmy.manager'
local config     = require 'config'
local task       = require 'task'
local files      = require 'files'
local uric       = require 'uri'
local capability = require 'capability'
local plugin     = require 'plugin'

local ErrorCodes = {
    -- Defined by JSON RPC
    ParseError           = -32700,
    InvalidRequest       = -32600,
    MethodNotFound       = -32601,
    InvalidParams        = -32602,
    InternalError        = -32603,
    serverErrorStart     = -32099,
    serverErrorEnd       = -32000,
    ServerNotInitialized = -32002,
    UnknownErrorCode     = -32001,

    -- Defined by the protocol.
    RequestCancelled     = -32800,
}

local CachedVM = setmetatable({}, {__mode = 'kv'})

---@class LSP
local mt = {}
mt.__index = mt
---@type files
mt._files = nil

function mt:_callMethod(name, params)
    local optional
    if name:sub(1, 2) == '$/' then
        name = name:sub(3)
        optional = true
    end
    local f = method[name]
    if f then
        local clock = os.clock()
        local suc, res = xpcall(f, debug.traceback, self, params)
        local passed = os.clock() - clock
        if passed > 0.2 then
            log.debug(('Task [%s] takes [%.3f]sec.'):format(name, passed))
        end
        if suc then
            return res
        else
            local ok, r = pcall(table.dump, params)
            local dump = ok and r or '<Cyclic table>'
            log.debug(('Task [%s] failed, params: %s'):format(
                name, dump
            ))
            log.error(res)
            if res:find 'not enough memory' then
                self:restartDueToMemoryLeak()
            end
            return nil, {
                code = ErrorCodes.InternalError,
                message = r .. '\n' .. res,
            }
        end
    end
    if optional then
        return nil
    else
        return nil, {
            code = ErrorCodes.MethodNotFound,
            message = 'MethodNotFound',
        }
    end
end

function mt:responseProto(id, response, err)
    local container = table.container()
    if err then
        container.error = err
    else
        container.result = response
    end
    rpc:response(id, container)
end

function mt:_doProto(proto)
    local id     = proto.id
    local name   = proto.method
    local params = proto.params
    local response, err = self:_callMethod(name, params)
    if not id then
        return
    end
    if type(response) == 'function' then
        response(function (final)
            self:responseProto(id, final)
        end)
    else
        self:responseProto(id, response, err)
    end
end

function mt:clearDiagnostics(uri)
    rpc:notify('textDocument/publishDiagnostics', {
        uri = uri,
        diagnostics = {},
    })
    self._needDiagnostics[uri] = nil
end

---@param uri uri
---@param compiled table
---@param mode string
---@return boolean
function mt:needCompile(uri, compiled, mode)
    self._needDiagnostics[uri] = true
    if self._needCompile[uri] then
        return false
    end
    if not compiled then
        compiled = {}
    end
    if compiled[uri] then
        return false
    end
    self._needCompile[uri] = compiled
    if mode == 'child' then
        table.insert(self._needCompile, uri)
    else
        table.insert(self._needCompile, 1, uri)
    end
    return true
end

function mt:isNeedCompile(uri)
    return self._needCompile[uri]
end

function mt:isWaitingCompile()
    if self._needCompile[1] then
        return true
    else
        return false
    end
end

---@param uri uri
---@param version integer
---@param text string
function mt:saveText(uri, version, text)
    self._lastLoadedVM = uri
    self._files:save(uri, text, version)
    self:needCompile(uri)
end

---@param uri uri
function mt:isDeadText(uri)
    return self._files:isDead(uri)
end

---@param uri uri
---@return boolean
function mt:isLua(uri)
    if not self.workspace then
        return true
    end
    local path = self.workspace:absolutePathByUri(uri)
    if not path then
        return false
    end
    if self.workspace:isLuaFile(path) then
        return true
    end
    return false
end

function mt:isIgnored(uri)
    if not self.workspace then
        return true
    end
    if not self.workspace.gitignore then
        return true
    end
    local path = self.workspace:relativePathByUri(uri)
    if not path then
        return true
    end
    if self.workspace.gitignore(path:string()) then
        return true
    end
    return false
end

---@param uri uri
---@param version integer
---@param text string
function mt:open(uri, version, text)
    if not self:isLua(uri) then
        return
    end
    self:saveText(uri, version, text)
    self._files:open(uri, text)
end

---@param uri uri
function mt:close(uri)
    self._files:close(uri)
    if self._files:isLibrary(uri) then
        return
    end
    if not self:isLua(uri) or self:isIgnored(uri) then
        self:removeText(uri)
    end
end

---@param uri uri
---@return boolean
function mt:isOpen(uri)
    return self._files:isOpen(uri)
end

---@param uri uri
---@param path path
---@param text string
function mt:checkReadFile(uri, path, text)
    if not text then
        log.debug('No file: ', path)
        return false
    end
    local size = #text / 1000.0
    if size > config.config.workspace.preloadFileSize then
        log.info(('Skip large file, size: %.3f KB: %s'):format(size, uri))
        return false
    end
    if self:getCachedFileCount() >= config.config.workspace.maxPreload then
        if not self._hasShowHitMaxPreload then
            self._hasShowHitMaxPreload = true
            rpc:notify('window/showMessage', {
                type = 3,
                message = lang.script('MWS_MAX_PRELOAD', config.config.workspace.maxPreload),
            })
        end
        return false
    end
    return true
end

---@param uri uri
---@param path path
---@param buf string
---@param compiled table
function mt:readText(uri, path, buf, compiled)
    if self._files:get(uri) then
        log.debug('Read failed due to duplicate:', uri)
        return
    end
    if not self:isLua(uri) then
        log.debug('Read failed due to not lua:', uri)
        return
    end
    if not self._files:isOpen() and self:isIgnored(uri) then
        log.debug('Read failed due to ignored:', uri)
        return
    end
    local text = buf or io.load(path)
    if not self._files:isOpen() and not self:checkReadFile(uri, path, text) then
        log.debug('Read failed due to check failed:', uri)
        return
    end
    self._files:save(uri, text, 0)
    self:needCompile(uri, compiled)
end

---@param uri uri
---@param path path
---@param buf string
---@param compiled table
function mt:readLibrary(uri, path, buf, compiled)
    if not self:isLua(uri) then
        return
    end
    if not self:checkReadFile(uri, path, buf) then
        return
    end
    self._files:save(uri, buf, 0)
    self._files:setLibrary(uri)
    self:needCompile(uri, compiled)
    self:clearDiagnostics(uri)
end

---@param uri uri
function mt:removeText(uri)
    self._files:remove(uri)
    self:compileVM(uri)
end

function mt:getCachedFileCount()
    return self._files:count()
end

function mt:reCompile()
    if self.global then
        self.global:remove()
    end
    if self.chain then
        self.chain:remove()
    end
    if self.emmy then
        self.emmy:remove()
    end

    local compiled = {}
    self._files:clearVM()

    for _, obj in pairs(listMgr.list) do
        if obj.type == 'source' or obj.type == 'function' then
            obj:kill()
        end
    end

    self.global = core.global(self)
    self.chain  = chainMgr()
    self.emmy   = emmyMgr()
    self.globalValue = nil
    self._compileTask:remove()
    self._needCompile = {}
    local n = 0
    for uri in self._files:eachFile() do
        self:needCompile(uri, compiled)
        n = n + 1
    end
    log.debug('reCompile:', n, self._files:count())

    self:_testMemory('skip')
end

function mt:reDiagnostic()
    for uri in self._files:eachFile() do
        self:clearDiagnostics(uri)
        self._needDiagnostics[uri] = true
    end
end

function mt:clearAllFiles()
    for uri in self._files:eachFile() do
        self:clearDiagnostics(uri)
    end
    self._files:clear()
end

---@param uri uri
function mt:loadVM(uri)
    local file = self._files:get(uri)
    if not file then
        return nil
    end
    if uri ~= self._lastLoadedVM then
        self:needCompile(uri)
    end
    if self._compileTask
        and not self._compileTask:isRemoved()
        and self._compileTask:get 'uri' == uri
    then
        self._compileTask:fastForward()
    else
        self:compileVM(uri)
    end
    if file:getVM() then
        self._lastLoadedVM = uri
    end
    return file:getVM(), file:getLines()
end

function mt:_markCompiled(uri, compiled)
    local newCompiled = self._needCompile[uri]
    if newCompiled then
        newCompiled[uri] = true
        self._needCompile[uri] = nil
    end
    for i, u in ipairs(self._needCompile) do
        if u == uri then
            table.remove(self._needCompile, i)
            break
        end
    end
    if newCompiled == compiled then
        return compiled
    end
    if not compiled then
        compiled = {}
    end
    for k, v in pairs(newCompiled) do
        compiled[k] = v
    end
    return compiled
end

---@param file file
---@return table
function mt:compileAst(file)
    local ast, err, comments = parser:parse(file:getText(), 'lua', config.config.runtime.version)
    file.comments = comments
    if ast then
        file:setAstErr(err)
    else
        if type(err) == 'string' then
            local message = lang.script('PARSER_CRASH', err)
            log.debug(message)
            rpc:notify('window/showMessage', {
                type = 3,
                message = lang.script('PARSER_CRASH', err:match '%.lua%:%d+%:(.+)' or err),
            })
            if message:find 'not enough memory' then
                self:restartDueToMemoryLeak()
            end
        end
    end
    return ast
end

---@param file file
---@param uri uri
function mt:_clearChainNode(file, uri)
    for pUri in file:eachParent() do
        local parent = self._files:get(pUri)
        if parent then
            parent:removeChild(uri)
        end
    end
end

---@param file file
---@param compiled table
function mt:_compileChain(file, compiled)
    if not compiled then
        compiled = {}
    end
    for uri in file:eachChild() do
        self:needCompile(uri, compiled, 'child')
    end
    for uri in file:eachParent() do
        self:needCompile(uri, compiled, 'parent')
    end
end

function mt:_compileGlobal(compiled)
    local uris = self.global:getAllUris()
    for _, uri in ipairs(uris) do
        self:needCompile(uri, compiled, 'global')
    end
end

function mt:_clearGlobal(uri)
    self.global:clearGlobal(uri)
end

function mt:_hasSetGlobal(uri)
    return self.global:hasSetGlobal(uri)
end

---@param uri uri
function mt:compileVM(uri)
    local file = self._files:get(uri)
    if not file then
        self:_markCompiled(uri)
        return nil
    end
    local compiled = self._needCompile[uri]
    if not compiled then
        return nil
    end
    file:removeVM()

    local clock = os.clock()
    local ast = self:compileAst(file)
    local version = file:getVersion()
    local astCost = os.clock() - clock
    if astCost > 0.1 then
        log.warn(('Compile Ast[%s] takes [%.3f] sec, size [%.3f]kb'):format(uri, astCost, #file:getText() / 1000))
    end
    file:clearOldText()

    self:_clearChainNode(file, uri)
    self:_clearGlobal(uri)

    local clock = os.clock()
    local vm, err = buildVM(ast, self, uri, file:getText())
    if vm then
        CachedVM[vm] = true
    end
    if self:isDeadText(uri)
        or file:isRemoved()
        or version ~= file:getVersion()
    then
        if vm then
            vm:remove()
        end
        return nil
    end
    if self._needCompile[uri] then
        self:_markCompiled(uri, compiled)
        self._needDiagnostics[uri] = true
    else
        if vm then
            vm:remove()
        end
        return nil
    end
    file:saveVM(vm, version, os.clock() - clock)

    local clock = os.clock()
    local lines = parser:lines(file:getText(), 'utf8')
    local lineCost = os.clock() - clock
    file:saveLines(lines, lineCost)

    if file:getVMCost() > 0.2 then
        log.debug(('Compile VM[%s] takes: %.3f sec'):format(uri, file:getVMCost()))
    end
    if not vm then
        error(err)
    end

    self:_compileChain(file, compiled)
    if self:_hasSetGlobal(uri) then
        self:_compileGlobal(compiled)
    end

    return file
end

---@param uri uri
function mt:doDiagnostics(uri)
    if not config.config.diagnostics.enable then
        self._needDiagnostics[uri] = nil
        return
    end
    if not self._needDiagnostics[uri] then
        return
    end
    local name = 'textDocument/publishDiagnostics'
    local file = self._files:get(uri)
    if not file
        or file:isRemoved()
        or not file:getVM()
        or file:getVM():isRemoved()
        or self._files:isLibrary(uri)
    then
        self._needDiagnostics[uri] = nil
        self:clearDiagnostics(uri)
        return
    end
    local data = {
        uri   = uri,
        vm    = file:getVM(),
        lines = file:getLines(),
        version = file:getVM():getVersion(),
    }
    local res = self:_callMethod(name, data)
    if self:isDeadText(uri) then
        return
    end
    if file:getVM():getVersion() ~= data.version then
        return
    end
    if self._needDiagnostics[uri] then
        self._needDiagnostics[uri] = nil
    else
        return
    end
    if res then
        rpc:notify(name, {
            uri = uri,
            diagnostics = res,
        })
    else
        self:clearDiagnostics(uri)
    end
end

---@param uri uri
---@return file
function mt:getFile(uri)
    return self._files:get(uri)
end

---@param uri uri
---@return VM
---@return table
---@return string
function mt:getVM(uri)
    local file = self._files:get(uri)
    if not file then
        return nil
    end
    return file:getVM(), file:getLines(), file:getText()
end

---@param uri uri
---@return string
---@return string
function mt:getText(uri)
    local file = self._files:get(uri)
    if not file then
        return nil
    end
    return file:getText(), file:getOldText()
end

function mt:getComments(uri)
    local file = self._files:get(uri)
    if not file then
        return nil
    end
    return file:getComments()
end

---@param uri uri
---@return table
function mt:getAstErrors(uri)
    local file = self._files:get(uri)
    if not file then
        return nil
    end
    return file:getAstErr()
end

---@param child uri
---@param parent uri
function mt:compileChain(child, parent)
    local parentFile = self._files:get(parent)
    local childFile = self._files:get(child)

    if not parentFile or not childFile then
        return
    end
    if parentFile == childFile then
        return
    end

    parentFile:addChild(child)
    childFile:addParent(parent)
end

function mt:checkWorkSpaceComplete()
    if self._hasCheckedWorkSpaceComplete then
        return
    end
    self._hasCheckedWorkSpaceComplete = true
    if self.workspace:isComplete() then
        return
    end
    self._needShowComplete = true
    rpc:notify('window/showMessage', {
        type = 3,
        message = lang.script.MWS_NOT_COMPLETE,
    })
end

function mt:_createCompileTask()
    if not self:isWaitingCompile() and not next(self._needDiagnostics) then
        if self._needShowComplete then
            self._needShowComplete = nil
            rpc:notify('window/showMessage', {
                type = 3,
                message = lang.script.MWS_COMPLETE,
            })
        end
    end
    self._compileTask = task(function ()
        self:doDiagnostics(self._lastLoadedVM)
        local uri = self._needCompile[1]
        if uri then
            self._compileTask:set('uri', uri)
            pcall(function () self:compileVM(uri) end)
        else
            uri = next(self._needDiagnostics)
            if uri then
                self:doDiagnostics(uri)
            end
        end
    end)
end

function mt:_doCompileTask()
    if not self._compileTask or self._compileTask:isRemoved() then
        self:_createCompileTask()
    end
    while true do
        local res = self._compileTask:step()
        if res == 'stop' then
            self._compileTask:remove()
            break
        end
        if self._compileTask:isRemoved() then
            break
        end
    end
    self:_loadProto()
end

function mt:_loadProto()
    while true do
        local ok, proto = self._proto:pop()
        if not ok then
            break
        end
        if proto.method then
            self:_doProto(proto)
        else
            rpc:recieve(proto)
        end
    end
end

function mt:restartDueToMemoryLeak()
    rpc:requestWait('window/showMessageRequest', {
        type = 3,
        message = lang.script('DEBUG_MEMORY_LEAK', '[Lua]'),
        actions = {
            {
                title = lang.script.DEBUG_RESTART_NOW,
            }
        }
    }, function ()
        os.exit(true)
    end)
    ac.wait(5, function ()
        os.exit(true)
    end)
end

function mt:reScanFiles()
    if not self.workspace then
        return
    end
    log.debug('reScanFiles')
    self:clearAllFiles()
    self.workspace:scanFiles()
end

function mt:onUpdateConfig(updated, other)
    local oldConfig = table.deepCopy(config.config)
    local oldOther  = table.deepCopy(config.other)
    config:setConfig(updated, other)
    local newConfig = config.config
    local newOther  = config.other
    if not table.equal(oldConfig.runtime, newConfig.runtime) then
        local library = require 'core.library'
        library.reload()
        self:reCompile()
    end
    if not table.equal(oldConfig.diagnostics, newConfig.diagnostics) then
        log.debug('reDiagnostic')
        self:reDiagnostic()
    end
    if newConfig.completion.enable then
        capability.completion.enable()
    else
        capability.completion.disable()
    end
    if not table.equal(oldConfig.plugin, newConfig.plugin) then
        plugin.load(self.workspace)
    end
    if not table.equal(oldConfig.workspace, newConfig.workspace)
    or not table.equal(oldConfig.plugin, newConfig.plugin)
    or not table.equal(oldOther.associations, newOther.associations)
    or not table.equal(oldOther.exclude, newOther.exclude)
    then
        self:reScanFiles()
    end
end

function mt:_testMemory(skipDead)
    local clock = os.clock()
    collectgarbage()
    log.debug('collectgarbage: ', ('%.3f'):format(os.clock() - clock))

    local clock = os.clock()
    local cachedVM = 0
    local cachedSource = 0
    local cachedFunction = 0
    for _, file in self._files:eachFile() do
        local vm = file:getVM()
        if vm and not vm:isRemoved() then
            cachedVM = cachedVM + 1
            cachedSource = cachedSource + #vm.sources
            cachedFunction = cachedFunction + #vm.funcs
        end
    end
    local aliveVM = 0
    local deadVM = 0
    for vm in pairs(CachedVM) do
        if vm:isRemoved() then
            deadVM = deadVM + 1
        else
            aliveVM = aliveVM + 1
        end
    end

    local alivedSource = 0
    local deadSource = 0
    for _, id in pairs(sourceMgr.watch) do
        if listMgr.get(id) then
            alivedSource = alivedSource + 1
        else
            deadSource = deadSource + 1
        end
    end

    local alivedFunction = 0
    local deadFunction = 0
    for _, id in pairs(functionMgr.watch) do
        if listMgr.get(id) then
            alivedFunction = alivedFunction + 1
        else
            deadFunction = deadFunction + 1
        end
    end

    local totalLocal = 0
    for _ in pairs(localMgr.watch) do
        totalLocal = totalLocal + 1
    end

    local totalValue = 0
    local deadValue = 0
    for value in pairs(valueMgr.watch) do
        totalValue = totalValue + 1
        if not value:getSource() then
            deadValue = deadValue + 1
        end
    end

    local totalEmmy = self.emmy:count()

    local mem = collectgarbage 'count'
    local threadInfo = async.info
    local threadBuf = {}
    for i, count in ipairs(threadInfo) do
        if count then
            threadBuf[i] = ('#%03d Mem:  [%.3f]kb'):format(i, count)
        else
            threadBuf[i] = ('#%03d Mem:  <Unknown>'):format(i)
        end
    end

    log.debug(('\n\z
    State\n\z
    Main Mem:  [%.3f]kb\n\z
    %s\n\z
-------------------\n\z
    CachedVM:  [%d]\n\z
    AlivedVM:  [%d]\n\z
    DeadVM:    [%d]\n\z
-------------------\n\z
    CachedSrc: [%d]\n\z
    AlivedSrc: [%d]\n\z
    DeadSrc:   [%d]\n\z
-------------------\n\z
    CachedFunc:[%d]\n\z
    AlivedFunc:[%d]\n\z
    DeadFunc:  [%d]\n\z
-------------------\n\z
    TotalVal:  [%d]\n\z
    DeadVal:   [%d]\n\z
-------------------\n\z
    TotalLoc:  [%d]\n\z
    TotalEmmy: [%d]\n\z'):format(
        mem,
        table.concat(threadBuf, '\n'),

        cachedVM,
        aliveVM,
        deadVM,

        cachedSource,
        alivedSource,
        deadSource,

        cachedFunction,
        alivedFunction,
        deadFunction,

        totalValue,
        deadValue,
        totalLocal,
        totalEmmy
    ))
    log.debug('test memory: ', ('%.3f'):format(os.clock() - clock))

    if deadValue / totalValue >= 0.5 and not skipDead then
        self:_testFindDeadValues()
    end
end

function mt:_testFindDeadValues()
    if self._testHasFoundDeadValues then
        return
    end
    self._testHasFoundDeadValues = true

    log.debug('Start find dead values, may takes few seconds...')

    local mark = {}
    local stack = {}
    local count = 0
    local clock = os.clock()
    local function push(info)
        stack[#stack+1] = info
    end
    local function pop()
        stack[#stack] = nil
    end
    local function showStack(uri)
        count = count + 1
        log.debug(uri, table.concat(stack, '->'))
    end
    local function scan(name, tbl)
        if count > 100 or os.clock() - clock > 5.0 then
            return
        end
        if type(tbl) ~= 'table' then
            return
        end
        if mark[tbl] then
            return
        end
        mark[tbl] = true
        if tbl.type then
            push(('%s<%s>'):format(name, tbl.type))
        else
            push(name)
        end
        if tbl.type == 'value' then
            if not tbl:getSource() then
                showStack(tbl.uri)
            end
        elseif tbl.type == 'files' then
            for k, v in tbl:eachFile() do
                scan(k, v)
            end
        else
            for k, v in pairs(tbl) do
                scan(k, v)
            end
        end
        pop()
    end
    scan('root', self._files)
    log.debug('Finish...')
end

function mt:onTick()
    self:_loadProto()
    self:_doCompileTask()
    if (os.clock() - self._clock >= 60 and not self:isWaitingCompile())
    or (os.clock() - self._clock >= 300)
    then
        self._clock = os.clock()
        self:_testMemory()
    end
end

function mt:listen()
    subprocess.filemode(io.stdin, 'b')
    subprocess.filemode(io.stdout, 'b')
    io.stdin:setvbuf 'no'
    io.stdout:setvbuf 'no'

    local _, out = async.run 'proto'
    self._proto = out

    local timerClock = 0.0
    while true do
        local startClock = os.clock()
        async.onTick()
        self:onTick()

        local delta = os.clock() - timerClock
        local suc, err = xpcall(updateTimer, log.error, delta)
        if not suc then
            io.stderr:write(err)
            io.stderr:flush()
        end
        timerClock = os.clock()

        local passedClock = os.clock() - startClock
        if passedClock > 0.1 then
            thread.sleep(0.0)
        else
            thread.sleep(0.001)
        end
    end
end

return function ()
    local session = setmetatable({
        _needCompile = {},
        _needDiagnostics = {},
        _clock = -100,
        _version = 0,
        _files = files(),
    }, mt)
    session.global = core.global(session)
    session.chain  = chainMgr()
    session.emmy   = emmyMgr()
    return session
end