print("Tiny Package Manager (TPM)")
print("Author: Kiritow")

local component=require("component")
local shell=require("shell")
local serialization=require("serialization")
local uuid=require("uuid")
local filesystem=require("filesystem")

local function showcmd(cmdstr,infostr)
    local old=component.gpu.setForeground(0xFFFF00)
    io.write(cmdstr)
    component.gpu.setForeground(0xFFFFFF)
    print("  " .. infostr)
    component.gpu.setForeground(old)
end
local function showerr(infostr)
    local old=component.gpu.setForeground(0xFF0000)
    print(infostr)
    component.gpu.setForeground(old)
end
local function cwrite(color,infostr)
    local old=component.gpu.setForeground(color)
    io.write(infostr)
    component.gpu.setForeground(old)
end

local function resolve_github(reponame,fileaddr,branch)
    if(branch==nil) then branch="master" end
    return "https://raw.githubusercontent.com/" .. reponame .. "/" .. branch .. "/" .. fileaddr
end
local function resolve_cngit(reponame,fileaddr,branch)
    return "http://kiritow.com:3000/" .. reponame .. "/raw/" .. branch .. "/" .. fileaddr
end

-- For Test Purpose only
resolve_github=resolve_cngit

local function beginWith(str,target)
    local a,b=string.find(str,target)
    if(a==nil) then return false
    else return (a==1) end
end

local args,ops=shell.parse(...)
local argc=#args

if(argc<1) then
    print("Usage:")
    showcmd("tpm install <package>",
        "Install package" ..
        "\n\tInstall via github: github+Author/Repo[/branch]. Branch is 'master' by default" ..
        "\n\tInstall via http: http+URL"
    )
    showcmd("tpm remove <package>","Remove package")
    showcmd("tpm list [-in] [<package>]",
        "Search package" ..
        "\n\t-i Only search installed package" ..
        "\n\t-n Only search not installed package"
    )
    showcmd("tpm update","Update software info")
    return
end

-- Hardware check
if(component.internet==nil) then
    showerr("No internet device found. tpm requires internet card to function normally.")
    return
end

-- Functions
local function doRealDownload(url)
    if(component.internet==nil) then
        error("The downloader requires an Internet card.")
    end
    local handle=component.internet.request(url)
    while true do
        local ret,err=handle.finishConnect()
        if(ret==nil) then
            return false,err
        elseif(ret==true) then
            break
        end
        --elseif(ret==false)
        --os.sleep(0.1)
    end
    local response_code=handle.response()
    local ans=""
    while true do
        local tmp=handle.read()
        if(tmp==nil) then break end
        ans=ans .. tmp
    end
    handle.close()
    return true,ans,response_code
end
function WriteStringToFile(StringValue,FileName,IsAppend)
    if(IsAppend==nil) then IsAppend=false end
    local handle,err
    if(IsAppend) then 
        handle,err=io.open(FileName,"a")
    else
        handle,err=io.open(FileName,"w")
    end
    if(handle==nil) then return false,err end

    handle:write(StringValue)
    handle:close()

    return true
end

-- TPM Main Programs
-- Installer
local function tpm_set_installed_list(tb)
    local f=io.open("/etc/tpm/list.bin","w")
    if(f==nil) then return false,"Unable to open file" end
    local content=serialization.serialize(tb)
    f:write(content)
    f:close()
    return true
end

local function tpm_get_installed_list()
    local f=io.open("/etc/tpm/list.bin","r")
    if(f==nil) then 
        f=io.open("/etc/tpm/list.bin","w")
        if(f==nil) then
            return false,"Unable to open file"
        else
            f:close()
            tpm_set_installed_list({})
            return true,{}
        end
    end
    local content=f:read("a")
    f:close()
    return true,serialization.unserialize(content)
end

local function tpm_is_installed(libname)
    local flg,tb=tpm_get_installed_list()
    if(not flg) then
        print("[tpm error] " .. tb)
        return false
    else
        for k,v in pairs(tb) do
            if(v.libname==libname) then
                return true
            end
        end
        return false
    end
end
local function tpm_mainfest_loader(data)
    local f,err=load("return " .. data,"Mainfest","t",{})
    if(f==nil) then
        return false,err
    end
    local tb=f()
    -- Check returned table
    if(tb.libname==nil  or tb.name==nil or tb.files==nil) then
        return false
    else
        return true,tb
    end
end
local function tpm_mainfest_show(mtb)
    print("Library Name: " .. mtb.name)
    print("libname: " .. mtb.libname)
    print("Info: " .. (mtb.info or "Not provided"))
    print("Author: " .. (mtb.author or "Not provided"))
    print("Version: " .. (mtb.version or "Not provided"))
    print("Setup: " .. (mtb.setup or "Not provided"))
    print("Uninst: " .. (mtb.uninst or "Not provided"))
    print("Required Directories: ")
    if(mtb.dirs==nil) then
        print("None")
    else
        for k,v in pairs(mtb.dirs) do
            print(v)
        end
    end
    print("Files:")
    for k,v in pairs(mtb.files) do
        print(k," -> ",v)
    end
    print("Dependency: ")
    if(mtb.depends==nil) then
        print("None")
    else
        for k,v in pairs(mtb.depends) do
            print(v)
        end
    end
end

local function tpm_install_github_real(repo,branch)
    local config_url=resolve_github(repo,"mainfest.txt",branch)
    local ret,data,code=doRealDownload(config_url)
    if(not ret) then
        return false,"Failed to download mainfest from repo " .. repo .. ". Error: " .. data
    end
    if(code~=200) then
        return false,"Got response code " .. code .. " while downloading mainfest from repo " .. repo
    end
    local flg,tb=tpm_mainfest_loader(data)
    if(not flg) then
        return false,"Invalid mainfest in repo " .. repo .. " Error: " .. tb
    end

    -- Debug
    tpm_mainfest_show(tb)

    -- Check
    if(tpm_is_installed(tb.libname)) then
        print("Package " .. tb.libname .. " is already installed.")
        return true
    end

    -- Depends
    if(tb.depends~=nil) then
        print("Analyzing dependency...")
        local dependsz=#tb.depends
        local cnt_now=1
        for k,v in pairs(tb.depends) do
            print("[" .. cnt_now .. "/" .. dependsz .. "] Checking " .. v .. "...")
            local ret,msg=tpm_install(v)
            if(not ret) then
                return false,"An error occurs while analyzing dependency: " .. v .. ". Error: " .. msg
            end
            cnt_now=cnt_now+1
        end
    end

    -- Make directories
    if(tb.dirs~=nil) then
        for k,v in pairs(tb.dirs) do
            print("Making directory " .. v)
            filesystem.makeDirectory(v)
        end
    end

    -- Download
    for k,v in pairs(tb.files) do
        io.write("Downloading file " .. k .. "...")
        local xret,xdata,xcode=doRealDownload(resolve_github(repo,k,branch))
        if(not xret) then
            print("[Failed]")
            return false,"Failed to download " .. k
        elseif(xcode~=200) then
            print("[Failed]")
            return false,"Response code is " .. xcode .. " while downloading " .. k
        else
            local xret,xmsg=WriteStringToFile(xdata,v)
            if(not xret) then
                print("[Write Failed]")
                return false,"Failed to write to file " .. v .. " while downloading " .. k
            end

            -- OK here
            print("[OK]")
        end
    end

    -- Run Setup
    if(tb.setup~=nil) then
        print("Running setup...")
        local setup_file=tb.files[tb.setup]
        local setup_fn,err=loadfile(setup_file)
        if(setup_fn==nil) then
            print("Failed to start setup program. Error: " .. err)
        end
        local ret,msg=pcall(setup_fn)
        if(not ret) then
            printf("Failed to run setup program. Error: " .. msg)
        end
    end

    -- Update software list
    print("Updating software info...")
    local flg,installed_lst=tpm_get_installed_list()
    table.insert(installed_lst,tb)
    tpm_set_installed_list(installed_lst)
    print("Software info updated.")
    return true
end
local function tpm_install_github(url)
    local a=string.find(url,"/")
    if(a==nil) then
        return false,"Unknown format of github url"
    end

    local author=string.sub(url,1,a-1)
    local reponame=''
    local b=string.find(url,"/",a+1)
    
    -- Branch set to master by default
    local branch="master"
    if(b~=nil) then
        reponame=string.sub(url,a+1,b-1)
        branch=string.sub(url,b+1)
    else
        reponame=string.sub(url,a+1)
    end

    local repo_fullname=author .. "/" .. reponame
    print("Checking github repo " .. repo_fullname .. " at branch " .. branch .." ...")

    return tpm_install_github_real(repo_fullname,branch)
end
local function tpm_install(install_url)
    print("tpm_install: ",install_url)
    if(beginWith(install_url,"github+")) then
        return tpm_install_github(string.sub(install_url,string.len("github+")+1))
    elseif(beginWith(install_url,"http+")) then
        return tpm_install_http(string.sub(install_url,string.len("http+")+1))
    else
        return tpm_install_package(install_url)
    end
end

if(args[1]=="install") then
    if(argc<2) then
        showerr("Package name or url is required.")
        return
    end
    for i=2,argc,1 do
        local ret,msg=tpm_install(args[i])
        if(not ret) then
            print("Failed to install task " .. (i-1) .. ". Error: " .. msg)
            break
        end
    end
end