local guide     = require 'parser.guide'
local util      = require 'utility'
local files     = require 'files'

local setmetatable = setmetatable
local assert       = assert
local require      = require
local type         = type
local running      = coroutine.running
local ipairs       = ipairs

_ENV = nil

---@class vm
local m = {}

function m.lock(tp, source)
    local co = running()
    local master = m.locked[co]
    if not master then
        master = {}
        m.locked[co] = master
    end
    if not master[tp] then
        master[tp] = {}
    end
    if master[tp][source] then
        return nil
    end
    master[tp][source] = true
    return function ()
        master[tp][source] = nil
    end
end

--- 获取link的uri
function m.getLinkUris(call)
    local workspace = require 'workspace'
    local func = call.node
    local name = func.special
    if name == 'require' then
        local args = call.args
        if not args[1] then
            return nil
        end
        local literal = guide.getLiteral(args[1])
        if type(literal) ~= 'string' then
            return nil
        end
        return workspace.findUrisByRequirePath(literal, true)
    end
end

function m.isSet(src)
    local tp = src.type
    if tp == 'setglobal'
    or tp == 'local'
    or tp == 'setlocal'
    or tp == 'setfield'
    or tp == 'setmethod'
    or tp == 'setindex'
    or tp == 'tablefield'
    or tp == 'tableindex' then
        return true
    end
    if tp == 'call' then
        local special = m.getSpecial(src.node)
        if special == 'rawset' then
            return true
        end
    end
    return false
end

function m.isGet(src)
    local tp = src.type
    if tp == 'getglobal'
    or tp == 'getlocal'
    or tp == 'getfield'
    or tp == 'getmethod'
    or tp == 'getindex' then
        return true
    end
    if tp == 'call' then
        local special = m.getSpecial(src.node)
        if special == 'rawget' then
            return true
        end
    end
    return false
end

function m.getArgInfo(source)
    local callargs = source.parent
    if not callargs or callargs.type ~= 'callargs' then
        return nil
    end
    local call = callargs.parent
    if not call or call.type ~= 'call' then
        return nil
    end
    for i = 1, #callargs do
        if callargs[i] == source then
            return call.node, i
        end
    end
    return nil
end

function m.getSpecial(source)
    if not source then
        return nil
    end
    return source.special
end

function m.getKeyName(source)
    if not source then
        return nil
    end
    if source.library then
        return 's|' .. source.name
    end
    if source.type == 'call' then
        local special = m.getSpecial(source.node)
        if special == 'rawset'
        or special == 'rawget' then
            return guide.getKeyName(source.args[2])
        end
    end
    return guide.getKeyName(source)
end

function m.mergeResults(a, b)
    for _, r in ipairs(b) do
        if not a[r] then
            a[r] = true
            a[#a+1] = r
        end
    end
    return a
end

m.cacheTracker = setmetatable({}, { __mode = 'kv' })

function m.flushCache()
    if m.cache then
        m.cache.dead = true
    end
    m.cacheVersion = files.globalVersion
    m.cache = {}
    m.locked = setmetatable({}, { __mode = 'k' })
    m.cacheTracker[m.cache] = true
end

function m.getCache(name)
    if m.cacheVersion ~= files.globalVersion then
        m.flushCache()
    end
    if not m.cache[name] then
        m.cache[name] = {}
    end
    return m.cache[name]
end

return m