LuaQuB.lua

---
--- Generated by EmmyLua(https://github.com/EmmyLua)
--- Created by wakfu.
--- DateTime: 2020/8/4 17:47
---

local luaqub, Compile = {}, {}

local function GetTrimStr(sInput)
    if type(sInput) ~= 'string' then
        return tostring(sInput)
    end
    local x = sInput:match "^%s*(.-)%s*$"
    return x
end

local function Trim(sInput)
    if type(sInput) ~= 'string' then
        return
    end
    local x = sInput:match "^%s*(.-)%s*$"
    return x
end

local function TableCopy(tInput)
    local tReturn = {}
    for k, v in pairs(tInput) do
        tReturn[k] = v
    end
    return tReturn
end

local function ParseString(sInput)
    local tReturn = {}
    for sMatch in sInput:gmatch("[^,]+") do
        table.insert(tReturn, Trim(sMatch))
    end
    return tReturn
end

local function ParseTable(tInput)
    local tReturn = {}
    for Key, Value in pairs(tInput) do
        if tonumber(Key) then
            table.insert(tReturn, Trim(Value))
        else
            table.insert(tReturn, ("%s `%s`"):format(Trim(Key), Trim(Value)))
        end
    end
    return tReturn
end

local function ParseWhere(sQuery, tWhere)
    local tInput = TableCopy(tWhere)
    if #tInput == 0 then
        return sQuery
    end
    sQuery = sQuery .. "\nWHERE " .. tInput[1].statement
    table.remove(tInput, 1)
    if #tInput == 0 then
        return sQuery
    end
    for _, tValue in ipairs(tInput) do
        sQuery = sQuery .. "\n\t" .. tValue.join .. " " .. tValue.statement
    end
    return sQuery
end

local function ParseHaving(sQuery, tHaving)
    local tInput = TableCopy(tHaving)
    if #tInput == 0 then
        return sQuery
    end
    sQuery = sQuery .. "\nHAVING " .. tInput[1].statement
    table.remove(tInput, 1)
    if #tInput == 0 then
        return sQuery
    end
    for _, tValue in ipairs(tInput) do
        sQuery = sQuery .. "\n\t" .. tValue.join .. " " .. tValue.statement
    end
    return sQuery
end

local function ParseJoins(sInput, Object)
    if #(Object._join) <= 0 then
        return sInput
    end
    for Key, tValue in pairs(Object._join) do
        sInput = sInput .. "\n" .. tValue.condition .. " " .. tValue.tbl .. "\n\tON " .. tValue.on
    end
    return sInput
end

local function ParseGroup(sInput, Object)
    if #(Object._group) <= 0 then
        return sInput
    end
    sInput = sInput .. "\nGROUP BY " .. table.concat(Object._group, ",\n\t")
    return sInput
end

local function ParseOrder(sInput, Object)
    if #(Object._order) <= 0 then
        return sInput
    end
    sInput, tOrder = sInput .. "\nORDER BY ", {}
    for Key, tValue in pairs(Object._order) do
        tOrder[#tOrder + 1] = tValue.col .. " " .. tValue.dir
    end
    return sInput .. table.concat(tOrder, ",\n\t")
end

function Compile.SELECT(Object)
    local sReturn, colNames, tbls = "SELECT ", table.concat(Object._select, ",\n\t"), table.concat(Object._from, ",\n\t")
    sReturn = sReturn .. colNames
    if #(Object._from) > 0 then
        sReturn = sReturn .. "\nFROM " .. tbls
    end
    sReturn = ParseJoins(sReturn, Object)
    sReturn = ParseWhere(sReturn, Object._where)
    sReturn = ParseGroup(sReturn, Object)
    sReturn = ParseHaving(sReturn, Object._having)
    sReturn = ParseOrder(sReturn, Object)
    if Object._limit > 0 then
        sReturn = sReturn .. "\nLIMIT " .. tostring(Object._limit)
    end
    if Object._offset > 0 then
        sReturn = sReturn .. "\nOFFSET " .. tostring(Object._offset)
    end
    return sReturn
end

function Compile.UPDATE(Object)
    if type(Object._from) ~= "string" then
        error("Update can be performed on a single table.")
        return false
    end
    local sReturn, tSet = "UPDATE " .. Object._from .. "\nSET ", {}
    for Key, Value in pairs(Object._update) do
        tSet[#tSet + 1] = Key .. " = " .. Value
    end
    sReturn = sReturn .. table.concat(tSet, ",\n\t")
    sReturn = ParseWhere(sReturn, Object._where)
    sReturn = ParseOrder(sReturn, Object)
    if Object._limit > 0 then
        sReturn = sReturn .. "\nLIMIT " .. tostring(Object._limit)
    end
    return sReturn
end

function Compile.DELETE(Object)
    if #(Object._from) == 0 then
        error("No table has been specified for DELETE call.")
        return false
    end
    local sReturn = "DELETE FROM " .. table.concat(Object._from, ",\n\t")
    sReturn = ParseWhere(sReturn, Object._where)
    if #(Object._from) == 1 then
        sReturn = ParseOrder(sReturn, Object)
        if Object._limit > 0 then
            sReturn = sReturn .. "\nLIMIT " .. tostring(Object._limit)
        end
    end
    return sReturn
end

function Compile.INSERT(Object)
    local tInsert = Object._insert
    local sReturn = ("INSERT INTO `%s` ( %s )\nVALUES\n(\n\t%s\n)"):format(tInsert.tbl, table.concat(tInsert.cols, ', '), table.concat(tInsert.val, ',\n\t'))
    return sReturn
end

luaqub.__index = luaqub

function luaqub:__tostring()
    return Compile[self._flag:upper()](self)
end

function luaqub:select(cols)
    if not cols then
        error("Argument to select function expected")
        return false
    end
    if type(cols) == "string" then
        if Trim(cols) == "*" then
            self._select = { '*' }
        else
            self._select, cols = ParseString(cols), nil
        end
    elseif type(cols) == "table" then
        self._select, cols = ParseTable(cols), nil
    end
    self._flag = "select"
    return self
end

function luaqub:from(tbls)
    if not tbls then
        error("Argument to from function expected")
        return false
    end
    if type(tbls) == "string" then
        self._from, tbls = ParseString(tbls), nil
    elseif type(tbls) == "table" then
        self._from, tbls = ParseTable(tbls), nil
    end
    return self
end

function luaqub:where(clauses, value, joiner)
    if not clauses then
        error("Matching clauses to where function expected")
        return false
    end
    if type(clauses) == "string" then
        if not joiner then
            joiner = 'and'
        end
        table.insert(self._where, { join = joiner:upper(), statement = ("%s %s"):format(GetTrimStr(clauses), GetTrimStr(value)) })
        clauses = nil
    elseif type(clauses) == "table" then
        if not value then
            value = 'and'
        end
        joiner = value:upper()
        for Key, Value in pairs(clauses) do
            if tonumber(Key) then
                table.insert(self._where, { join = joiner, statement = Value })
            else
                table.insert(self._where, { join = joiner, statement = ("`%s` = '%s'"):format(GetTrimStr(Key), GetTrimStr(Value)) })
            end
        end
        clauses = nil
    end
    return self
end

function luaqub:having(clauses, value, joiner)
    if not clauses then
        error("Matching clauses to having function expected")
        return false
    end
    if type(clauses) == "string" then
        if not joiner then
            joiner = 'and'
        end
        table.insert(self._having, { join = joiner:upper(), statement = Trim(clauses) .. " " .. Trim(value) })
        clauses = nil
    elseif type(clauses) == "table" then
        if not value then
            value = 'and'
        end
        joiner = value:upper()
        for Key, Value in pairs(clauses) do
            if tonumber(Key) then
                table.insert(self._having, { join = joiner, statement = Value })
            else
                table.insert(self._having, { join = joiner, statement = ("%s = %s"):format(Trim(Key), Trim(Value)) })
            end
        end
        clauses = nil
    end
    return self
end

function luaqub:join(tbl, clause, cond)
    if not cond then
        cond = "JOIN"
    else
        cond = Trim(cond:upper()) .. " JOIN"
    end
    if type(clause) == "string" then
        clause = Trim(clause)
    end
    table.insert(self._join, { condition = cond, tbl = tbl, on = clause })
    return self
end

function luaqub:limit(lim, off)
    if not tonumber(lim) then
        error("Limit argument should be a number")
        return false
    end
    if off then
        if not tonumber(off) then
            error("Offset argument should be a number")
            return false
        end
        self._offset = tonumber(off)
    end
    self._limit = tonumber(lim)
    return self
end

function luaqub:order(col, dir)
    if not col then
        error("Blank call of order function is not allowed")
        return false
    end
    if type(col) == "string" then
        dir = (dir and dir:upper()) or "ASC"
        table.insert(self._order, { col = col, dir = dir })
    elseif type(col) == "table" then
        for Key, Value in pairs(col) do
            if tonumber(Key) then
                table.insert(self._order, { col = Value, dir = "ASC" })
            else
                table.insert(self._order, { col = Key, dir = Value:upper() })
            end
        end
    end
    return self
end

function luaqub:group(col)
    if not col then
        error("Blank call of group function is not allowed")
        return false
    end
    if type(col) == "string" then
        table.insert(self._group, col)
    elseif type(col) == "table" then
        for Key, Value in pairs(col) do
            table.insert(self._group, Value)
        end
    end
    return self
end

function luaqub:update(tbl, datas)
    if type(tbl) ~= 'string' then
        error("Update can be performed on a single table.")
        return false
    end
    if type(datas) ~= 'table' then
        error("Unexpected argument #2 to update. Table expected, got " .. type(datas))
        return false
    end

    local formatData = {}
    for Key, Value in pairs(datas) do
        if tonumber(Key) then
            error("Unexpected argument is key value" .. type(datas))
            return false
        else
            formatData[("`%s`"):format(GetTrimStr(Key))] = ("'%s'"):format(GetTrimStr(Value))
        end
    end

    self._from, self._flag, self._update = tbl, 'update', formatData
    return self
end

function luaqub:delete()
    self._flag = 'delete'
    return self
end

function luaqub:insert(tbl, datas)
    if not datas or type(datas) ~= 'table' then
        error("Unexpected argument #2 passed to insert function.")
        return false
    end
    if type(tbl) ~= 'string' then
        error("String argument expected for insert function.")
        return false
    end
    local tCols, tValue = {}, {}
    for Key, Value in pairs(datas) do
        table.insert(tCols, ('`%s`'):format(Trim(Key)))
        if not tonumber(Value) then
            table.insert(tValue, ("'%s'"):format(Trim(Value)))
        else
            table.insert(tValue, ("'%d'"):format(Value))
        end
    end
    self._flag, self._insert.cols, self._insert.val, self._insert.tbl = 'insert', tCols, tValue, tbl
    return self
end

function luaqub.new()
    local tNew = {
        _select = {},
        _update = {},
        _from = {},
        _where = {},
        _join = {},
        _order = {},
        _group = {},
        _having = {},
        _insert = {},
        _limit = 0,
        _offset = 0,
        _flag = '',
    }
    setmetatable(tNew, luaqub)
    return tNew
end

return luaqub