local noder     = require 'core.noder'
local guide     = require 'parser.guide'
local files     = require 'files'
local generic   = require 'core.generic'
local ws        = require 'workspace'
local vm        = require 'vm.vm'
local collector = require 'core.collector'

local ignoredSources = {
    ['int:']             = true,
    ['num:']             = true,
    ['str:']             = true,
    ['bool:']            = true,
    ['nil:']             = true,
}

local ignoredIDs = {
    ['dn:unknown']       = true,
    ['dn:nil']           = true,
    ['dn:any']           = true,
    ['dn:boolean']       = true,
    ['dn:table']         = true,
    ['dn:number']        = true,
    ['dn:integer']       = true,
    ['dn:userdata']      = true,
    ['dn:lightuserdata'] = true,
    ['dn:function']      = true,
    ['dn:thread']        = true,
}

local m = {}

---@alias guide.searchmode '"ref"'|'"def"'|'"field"'|'"allref"'|'"alldef"'

---添加结果
---@param status guide.status
---@param mode   guide.searchmode
---@param source parser.guide.object
---@param force  boolean
function m.pushResult(status, mode, source, force)
    if not source then
        return
    end
    local results = status.results
    local mark = status.rmark
    if mark[source] then
        return
    end
    mark[source] = true
    if force then
        results[#results+1] = source
        return
    end
    local parent = source.parent
    if mode == 'def' or mode == 'alldef' then
        if source.type == 'local'
        or source.type == 'setlocal'
        or source.type == 'setglobal'
        or source.type == 'label'
        or source.type == 'setfield'
        or source.type == 'setmethod'
        or source.type == 'setindex'
        or source.type == 'tableindex'
        or source.type == 'tablefield'
        or source.type == 'function'
        or source.type == 'table'
        or source.type == 'doc.class.name'
        or source.type == 'doc.alias.name'
        or source.type == 'doc.field.name'
        or source.type == 'doc.type.enum'
        or source.type == 'doc.resume'
        or source.type == 'doc.type.array'
        or source.type == 'doc.type.table'
        or source.type == 'doc.type.function' then
            results[#results+1] = source
            return
        end
        if source.type == 'call' then
            if source.node.special == 'rawset' then
                results[#results+1] = source
            end
        end
        if parent.type == 'return' then
            if noder.getID(source) ~= status.id then
                results[#results+1] = source
            end
        end
    elseif mode == 'ref' or mode == 'field' or mode == 'allref' then
        if source.type == 'local'
        or source.type == 'setlocal'
        or source.type == 'getlocal'
        or source.type == 'setglobal'
        or source.type == 'getglobal'
        or source.type == 'label'
        or source.type == 'goto'
        or source.type == 'setfield'
        or source.type == 'getfield'
        or source.type == 'setmethod'
        or source.type == 'getmethod'
        or source.type == 'setindex'
        or source.type == 'getindex'
        or source.type == 'tableindex'
        or source.type == 'tablefield'
        or source.type == 'function'
        or source.type == 'table'
        or source.type == 'string'
        or source.type == 'boolean'
        or source.type == 'number'
        or source.type == 'integer'
        or source.type == 'nil'
        or source.type == 'doc.class.name'
        or source.type == 'doc.type.name'
        or source.type == 'doc.alias.name'
        or source.type == 'doc.extends.name'
        or source.type == 'doc.field.name'
        or source.type == 'doc.type.enum'
        or source.type == 'doc.resume'
        or source.type == 'doc.type.array'
        or source.type == 'doc.type.table'
        or source.type == 'doc.type.function' then
            results[#results+1] = source
            return
        end
        if source.type == 'call' then
            if source.node.special == 'rawset'
            or source.node.special == 'rawget' then
                results[#results+1] = source
            end
        end
        if parent.type == 'return' then
            if noder.getID(source) ~= status.id then
                results[#results+1] = source
            end
        end
    end
end

---获取uri
---@param  obj parser.guide.object
---@return uri
function m.getUri(obj)
    if obj.uri then
        return obj.uri
    end
    local root = guide.getRoot(obj)
    if root then
        return root.uri
    end
    return ''
end

---@param obj parser.guide.object
---@return parser.guide.object?
function m.getObjectValue(obj)
    while obj.type == 'paren' do
        obj = obj.exp
        if not obj then
            return nil
        end
    end
    if obj.type == 'boolean'
    or obj.type == 'number'
    or obj.type == 'integer'
    or obj.type == 'string' then
        return obj
    end
    if obj.value then
        return obj.value
    end
    if obj.type == 'field'
    or obj.type == 'method' then
        return obj.parent and obj.parent.value
    end
    if obj.type == 'call' then
        if obj.node.special == 'rawset' then
            return obj.args and obj.args[3]
        else
            return obj
        end
    end
    if obj.type == 'select' then
        return obj
    end
    return nil
end

local function checkLock(status, k1, k2)
    local locks = status.lock
    local lock1 = locks[k1]
    if not lock1 then
        lock1 = {}
        locks[k1] = lock1
    end
    if lock1[''] then
        return true
    end
    if k2 == nil then
        k2 = ''
    end
    if lock1[k2] then
        return true
    end
    lock1[k2] = true
    return false
end

local strs = {}
local function footprint(status, ...)
    if TRACE then
        log.debug(...)
    end
    if FOOTPRINT then
        local n = select('#', ...)
        for i = 1, n do
            strs[i] = tostring(select(i, ...))
        end
        status.footprint[#status.footprint+1] = table.concat(strs, '\t', 1, n)
    end
end

local function crossSearch(status, uri, expect, mode, sourceUri)
    if checkLock(status, uri, expect) then
        return
    end
    footprint(status, 'crossSearch', uri, expect)
    m.searchRefsByID(status, uri, expect, mode)
    --status.lock[uri] = nil
    footprint(status, 'crossSearch finish, back to:', sourceUri)
end

local function checkCache(status, uri, expect, mode)
    local cache = vm.getCache('search:' .. mode)
    local fileCache = cache[uri]
    if not fileCache then
        fileCache = {}
        cache[uri] = fileCache
    end
    if fileCache[expect] then
        for _, res in ipairs(fileCache[expect]) do
            m.pushResult(status, mode, res, true)
        end
        return true
    end
    fileCache[expect] = status.results
    return false
end

local function stop(status, msg)
    if TEST then
        if FOOTPRINT then
            log.debug(table.concat(status.footprint, '\n'))
        end
        error(msg)
    else
        log.warn(msg)
        if FOOTPRINT then
            log.debug(table.concat(status.footprint, '\n'))
        end
        return
    end
end

local function checkSLock(status, slock, id, field)
    if noder.getIDLength(id) > 20 then
        stop(status, 'too long!')
        return false
    end
    local cmark = slock[id]
    if not cmark then
        cmark = {}
        slock[id] = {}
    end
    if cmark[field or ''] then
        return false
    end
    cmark[field or ''] = true
    local right = ''
    while field and field ~= '' do
        local lastID = noder.getLastID(field)
        if not lastID then
            break
        end
        right = lastID .. right
        if cmark[right] then
            return false
        end
        field = field:sub(1, - #lastID - 1)
    end
    return true
end

local function isCallID(field)
    if not field then
        return false
    end
    if field:sub(1, 2) == noder.RETURN_INDEX then
        return true
    end
    return false
end

function m.searchRefsByID(status, uri, expect, mode)
    local ast = files.getState(uri)
    if not ast then
        return
    end
    local root = ast.ast
    local searchStep
    noder.compileNodes(root)

    status.id = expect

    local callStack = status.callStack

    local slock = status.slock[uri] or {}
    local elock = status.elock[uri] or {}
    status.slock[uri] = slock
    status.elock[uri] = elock

    local function search(id, field)
        local firstID = noder.getFirstID(id)
        if ignoredIDs[firstID] and (field or firstID ~= id) then
            return
        end
        if not checkSLock(status, slock, id, field) then
            footprint(status, 'slocked:', id, field)
            return
        end
        footprint(status, 'search:', id, field)
        searchStep(id, field)
        footprint(status, 'pop:', id, field)
    end

    local function splitID(id, field)
        if field then
            return
        end
        local leftID = ''
        local rightID

        while true do
            local firstID = noder.getHeadID(rightID or id)
            if not firstID or firstID == id then
                return
            end
            leftID  = leftID .. firstID
            if leftID == id then
                return
            end
            rightID = id:sub(#leftID + 1)
            search(leftID, rightID)
            local isCall = isCallID(firstID)
            if isCall then
                break
            end
        end
    end

    local function searchID(id, field)
        if not id then
            return
        end
        if field then
            id = id .. field
        end
        search(id, nil)
    end

    ---@return parser.guide.object?
    local function findLastCall()
        for i = #callStack, 1, -1 do
            local call = callStack[i]
            if call then
                -- 标记此处的call失效，等待在堆栈平衡时弹出
                callStack[i] = false
                return call
            end
        end
        return nil
    end

    local genericCallArgs = {}
    local closureCache = {}
    local function checkGeneric(source, field)
        if not source.isGeneric then
            return
        end
        if not isCallID(field) then
            return
        end
        local call = findLastCall()
        if not call then
            return
        end

        if call.args then
            for _, arg in ipairs(call.args) do
                genericCallArgs[arg] = true
            end
        end

        local cacheID = noder.getID(source) .. noder.getID(call)
        local closure = closureCache[cacheID]
        if closure == false then
            return
        end
        if not closure then
            closure = generic.createClosure(source, call)
            closureCache[cacheID] = closure or false
            if not closure then
                return
            end
        end
        local id = noder.getID(closure)
        searchID(id, field)
    end

    local function checkENV(source, field)
        if not field then
            return
        end
        if source.special ~= '_G' then
            return
        end
        local newID = 'g:' .. field:sub(2)
        searchID(newID)
    end

    local ftag = {}
    local btag = {}

    local function checkThenPushTag(ward, tag)
        if not tag or tag == 'deep' then
            return true
        end
        local checkTags
        local pushTags
        if ward == 'forward' then
            checkTags = btag
            pushTags  = ftag
        else
            checkTags = ftag
            pushTags  = btag
        end
        if checkTags[tag] and checkTags[tag] > 0 then
            return false
        end
        pushTags[tag] = (pushTags[tag] or 0) + 1
        return true
    end

    local function popTag(ward, tag)
        if not tag or tag == 'deep' then
            return
        end
        local popTags
        if ward == 'forward' then
            popTags = ftag
        else
            popTags = btag
        end
        popTags[tag] = popTags[tag] - 1
    end

    local function checkForward(id, node, field)
        for forwardID, tag in noder.eachForward(node) do
            if not checkThenPushTag('forward', tag) then
                goto CONTINUE
            end
            local targetUri, targetID = noder.getUriAndID(forwardID)
            if targetUri and not files.eq(targetUri, uri) then
                crossSearch(status, targetUri, targetID .. (field or ''), mode, uri)
            else
                searchID(targetID or forwardID, field)
            end
            popTag('forward', tag)
            ::CONTINUE::
        end
    end

    local function checkBackward(id, node, field)
        if ignoredIDs[id] then
            return
        end
        if mode ~= 'ref' and mode ~= 'field' and mode ~= 'allref' and not field then
            return
        end
        for backwardID, tag in noder.eachBackward(node) do
            if tag == 'deep' and mode ~= 'allref' and mode ~= 'alldef' then
                goto CONTINUE
            end
            if not checkThenPushTag('backward', tag) then
                goto CONTINUE
            end
            local targetUri, targetID = noder.getUriAndID(backwardID)
            if targetUri and not files.eq(targetUri, uri) then
                crossSearch(status, targetUri, targetID .. (field or ''), mode, uri)
            else
                searchID(targetID or backwardID, field)
            end
            popTag('backward', tag)
            ::CONTINUE::
        end
    end

    local function searchSpecial(id, field)
        -- Special rule: ('').XX -> stringlib.XX
        if id == 'str:'
        or id == 'dn:string' then
            if field or mode == 'field' then
                searchID('dn:stringlib', field)
            else
                searchID('dn:string', field)
            end
        end
    end

    local function checkRequire(requireName, field)
        local tid = 'mainreturn' .. (field or '')
        local uris = ws.findUrisByRequirePath(requireName)
        footprint(status, ('require %q:\n%s'):format(requireName, table.concat(uris, '\n')))
        for _, ruri in ipairs(uris) do
            if not files.eq(uri, ruri) then
                crossSearch(status, ruri, tid, mode, uri)
            end
        end
    end

    local function searchGlobal(id, node, field)
        if id:sub(1, 2) ~= 'g:' then
            return
        end
        if checkLock(status, id, field) then
            return
        end
        local tid = id .. (field or '')
        footprint(status, ('checkGlobal:%s + %s'):format(id, field, tid))
        local crossed = {}
        if mode == 'def' or mode == 'alldef' then
            for _, guri in collector.each('def:' .. id) do
                if files.eq(uri, guri) then
                    goto CONTINUE
                end
                crossSearch(status, guri, tid, mode, uri)
                ::CONTINUE::
            end
        else
            for _, guri in collector.each(id) do
                if crossed[guri] then
                    goto CONTINUE
                end
                if mode == 'def' or mode == 'alldef' then
                    goto CONTINUE
                end
                if files.eq(uri, guri) then
                    goto CONTINUE
                end
                crossSearch(status, guri, tid, mode, uri)
                ::CONTINUE::
            end
        end
    end

    local function searchClass(id, node, field)
        if id:sub(1, 3) ~= 'dn:' then
            return
        end
        if checkLock(status, id, field) then
            return
        end
        local tid = id .. (field or '')
        local sid = id
        if ignoredIDs[id]
        or id == 'dn:string' then
            sid = 'def:' .. sid
        end
        for _, guri in collector.each(sid) do
            if not files.eq(uri, guri) then
                crossSearch(status, guri, tid, mode, uri)
            end
        end
    end

    local function checkMainReturn(id, node, field)
        if id ~= 'mainreturn' then
            return
        end
        local calls = vm.getLinksTo(uri)
        for _, call in ipairs(calls) do
            local curi = guide.getUri(call)
            local cid  = ('%s%s'):format(
                noder.getID(call),
                field or ''
            )
            if not files.eq(curi, uri) then
                crossSearch(status, curi, cid, mode, uri)
            end
        end
    end

    local function lockExpanding(id, field)
        local locked = elock[id]
        if locked and field then
            if #locked <= #field then
                if field:sub(-#locked) == locked then
                    footprint(status, 'elocked:', id, locked, field)
                    return false
                end
            end
        end
        elock[id] = field
        return true
    end

    local function releaseExpanding(id, field)
        elock[id] = nil
    end

    local function searchNode(id, node, field)
        if node.call then
            callStack[#callStack+1] = node.call
        end
        if field == nil and node.source and not ignoredSources[id] then
            for source in noder.eachSource(node) do
                local force = genericCallArgs[source]
                m.pushResult(status, mode, source, force)
            end
        end

        if node.require then
            checkRequire(node.require, field)
        end

        if lockExpanding(id, field) then
            if node.forward then
                checkForward(id, node, field)
            end
            if node.backward then
                checkBackward(id, node, field)
            end
            releaseExpanding(id, field)
        end

        if node.source then
            checkGeneric(node.source, field)
            checkENV(node.source, field)
        end

        if mode == 'allref' or mode == 'alldef' then
            checkMainReturn(id, node, field)
        end

        if node.call then
            callStack[#callStack] = nil
        end

        return false
    end

    local function searchAnyField(id, field)
        if mode == 'ref' or mode == 'allref' then
            return
        end
        local lastID = noder.getLastID(id)
        if not lastID then
            return
        end
        local originField = id:sub(#lastID + 1)
        if originField == noder.TABLE_KEY
        or originField == noder.WEAK_TABLE_KEY then
            return
        end
        local anyFieldID   = lastID .. noder.ANY_FIELD
        local anyFieldNode = noder.getNodeByID(root, anyFieldID)
        if anyFieldNode then
            searchNode(anyFieldID, anyFieldNode, field)
        end
    end

    local function searchWeak(id, field)
        local lastID = noder.getLastID(id)
        if not lastID then
            return
        end
        local originField = id:sub(#lastID + 1)
        if originField == noder.WEAK_TABLE_KEY then
            local newID   = lastID .. noder.TABLE_KEY
            local newNode = noder.getNodeByID(root, newID)
            if newNode then
                searchNode(newID, newNode, field)
            end
        end
        if originField == noder.WEAK_ANY_FIELD then
            local newID   = lastID .. noder.ANY_FIELD
            local newNode = noder.getNodeByID(root, newID)
            if newNode then
                searchNode(newID, newNode, field)
            end
        end
    end

    local stepCount = 0
    local stepMaxCount = 1e3
    local statusMaxCount = 1e4
    if mode == 'allref' or mode == 'alldef' then
        stepMaxCount = 1e4
        statusMaxCount = 1e5
    end
    function searchStep(id, field)
        stepCount = stepCount + 1
        status.count = status.count + 1
        if stepCount > stepMaxCount
        or status.count > statusMaxCount then
            stop(status, 'too deep!')
            return
        end
        searchSpecial(id, field)
        local node = noder.getNodeByID(root, id)
        if node then
            searchNode(id, node, field)
            if node.skip and field then
                return
            end
        end
        searchGlobal(id, node, field)
        searchClass(id, node, field)
        splitID(id, field)
        searchAnyField(id, field)
        searchWeak(id, field)
    end

    search(expect)

    --清除来自泛型的临时对象
    for _, closure in pairs(closureCache) do
        noder.removeID(root, noder.getID(closure))
        if closure then
            for _, value in ipairs(closure.values) do
                noder.removeID(root, noder.getID(value))
            end
        end
    end
end

local function prepareSearch(source)
    if source.type == 'field'
    or source.type == 'method' then
        source = source.parent
    end
    if not source then
        return
    end
    local root = guide.getRoot(source)
    noder.compileNodes(root)
    local uri  = guide.getUri(source)
    local id   = noder.getID(source)
    return uri, id
end

local function getField(status, source, mode)
    if source.type == 'table' then
        for _, field in ipairs(source) do
            if field.type == 'tablefield'
            or field.type == 'tableindex' then
                m.pushResult(status, mode, field)
            end
        end
        return
    end
    if source.type == 'doc.class.name' then
        local class = source.parent
        for _, field in ipairs(class.fields) do
            m.pushResult(status, mode, field.field)
        end
        return
    end
    local field = source.next
    if field then
        if field.type == 'getmethod'
        or field.type == 'setmethod'
        or field.type == 'getfield'
        or field.type == 'setfield'
        or field.type == 'getindex'
        or field.type == 'setindex' then
            m.pushResult(status, mode, field)
        end
        return
    end
end

local function searchAllGlobalByUri(status, mode, uri, fullID)
    local ast = files.getState(uri)
    if not ast then
        return
    end
    local root = ast.ast
    noder.compileNodes(root)
    local noders = noder.getNoders(root)
    if fullID then
        for id, node in pairs(noders) do
            if  node.source
            and id == fullID then
                for source in noder.eachSource(node) do
                    m.pushResult(status, mode, source)
                end
            end
        end
    else
        for id, node in pairs(noders) do
            if  node.source
            and id:sub(1, 2) == 'g:'
            and not id:find(noder.SPLIT_CHAR) then
                for source in noder.eachSource(node) do
                    m.pushResult(status, mode, source)
                end
            end
        end
    end
end

local function searchAllGlobals(status, mode)
    for uri in files.eachFile() do
        searchAllGlobalByUri(status, mode, uri)
    end
end

---查找全局变量
---@param uri uri
---@param mode guide.searchmode
---@param name string
---@return parser.guide.object[]
function m.findGlobals(uri, mode, name)
    local status = m.status(mode)

    if name then
        local fullID = ('g:%q'):format(name)
        searchAllGlobalByUri(status, mode, uri, fullID)
    else
        searchAllGlobalByUri(status, mode, uri)
    end

    return status.results
end

---搜索对象的引用
---@param status guide.status
---@param source parser.guide.object
---@param mode   guide.searchmode
function m.searchRefs(status, source, mode)
    local uri, id = prepareSearch(source)
    if not id then
        return
    end

    if checkCache(status, uri, id, mode) then
        return
    end

    if TRACE then
        log.debug('searchRefs:', id)
    end
    m.searchRefsByID(status, uri, id, mode)
end

---搜索对象的field
---@param status guide.status
---@param source parser.guide.object
---@param mode   guide.searchmode
---@param field  string
function m.searchFields(status, source, mode, field)
    local uri, id = prepareSearch(source)
    if not id then
        return
    end
    if TRACE then
        log.debug('searchFields:', id, field)
    end
    if field == '*' then
        if source.special == '_G' then
            if checkCache(status, uri, '*', mode) then
                return
            end
            searchAllGlobals(status, mode)
        else
            if checkCache(status, uri, id .. '*', mode) then
                return
            end
            local newStatus = m.status('field')
            m.searchRefsByID(newStatus, uri, id, 'field')
            for _, def in ipairs(newStatus.results) do
                getField(status, def, mode)
            end
        end
    else
        if source.special == '_G' then
            local fullID = ('g:%q'):format(field)
            if checkCache(status, uri, fullID, mode) then
                return
            end
            m.searchRefsByID(status, uri, fullID, mode)
        else
            local fullID = ('%s%s%q'):format(id, noder.SPLIT_CHAR, field)
            if checkCache(status, uri, fullID, mode) then
                return
            end
            m.searchRefsByID(status, uri, fullID, mode)
        end
    end
end

---@class guide.status
---搜索结果
---@field results parser.guide.object[]
---@field rmark   table
---@field id      string

---创建搜索状态
---@param mode guide.searchmode
---@return guide.status
function m.status(mode)
    local status = {
        callStack = {},
        crossed   = {},
        lock      = {},
        slock     = {},
        elock     = {},
        results   = {},
        rmark     = {},
        smark     = {},
        footprint = {},
        count     = 0,
        ftag      = {},
        btag      = {},
        cache     = vm.getCache('searcher:' .. mode)
    }
    return status
end

--- 请求对象的引用
---@param obj       parser.guide.object
---@param field?    string
---@return parser.guide.object[]
function m.requestReference(obj, field)
    local status = m.status('ref')

    if field then
        m.searchFields(status, obj, 'ref', field)
    else
        m.searchRefs(status, obj, 'ref')
    end

    return status.results
end

--- 请求对象的全部引用（深度搜索）
---@param obj       parser.guide.object
---@param field?    string
---@return parser.guide.object[]
function m.requestAllReference(obj, field)
    local status = m.status('allref')

    if field then
        m.searchFields(status, obj, 'allref', field)
    else
        m.searchRefs(status, obj, 'allref')
    end

    return status.results
end

--- 请求对象的定义
---@param obj       parser.guide.object
---@param field?    string
---@return parser.guide.object[]
function m.requestDefinition(obj, field)
    local status = m.status('def')

    if field then
        m.searchFields(status, obj, 'def', field)
    else
        m.searchRefs(status, obj, 'def')
    end

    return status.results
end

--- 请求对象的全部定义（深度搜索）
---@param obj       parser.guide.object
---@param field?    string
---@return parser.guide.object[]
function m.requestAllDefinition(obj, field)
    local status = m.status('alldef')

    if field then
        m.searchFields(status, obj, 'alldef', field)
    else
        m.searchRefs(status, obj, 'alldef')
    end

    return status.results
end

--m.requestReference = m.requestAllReference
--m.requestDefinition = m.requestAllDefinition

return m