--[[

Usages:
> gitgud sync <repo path> <local path>
download file from repo

> gitgud delete <local path>
delete downloaded file

> gitgud
re-download all synced files

> gitgud run <repo path>
fetch and exec file from repo

]]

if not http then error("http is not enabled") end

local function get(url)
    local response, err = http.get(url)
    if not response then
        return nil, err
    end

    local status, err = response.getResponseCode()
    if status ~= 200 then
        return nil, (status .. " " .. err)
    end

    local result = response.readAll()
    response.close()
    return result
end

local function ensure_dotlua(path)
    if string.match(path, "%.lua$") then
        return path
    else
        return path .. ".lua"
    end
end

local function gitea_url(path)
    return "https://git.leafbla.de/dominic/turtles/raw/branch/master/".. path
end

local function download_file(repo_path, local_path)
    write("Downloading " .. repo_path .. " as " .. local_path .. "... ")
    local result, err = get(gitea_url(repo_path))
    if not result then
        print()
        printError(err)
        return false
    end

    local f = fs.open(local_path, "w")
    f.write(result)
    f.close()

    print("OK")
    return true
end

-- keep track of downloaded files
local storage_path = ".gitgud"

local storage = {}   
if fs.exists(storage_path) then
    local f = fs.open(storage_path, "r")
    storage = textutils.unserialize(f.readAll())
    f.close()
end

local function update_storage()
    local f = fs.open(storage_path, "w")
    f.write(textutils.serialize(storage))
    f.close()
end

local args = {...}

if #args == 0 then

    -- Lua being Lua, of course #storage won't work
    local count = 0
    for _ in pairs(storage) do
        count = count + 1
    end

    print("Syncing " .. count .. " files.")

    local success_count = 0
    for local_path, repo_path in pairs(storage) do
        local success = download_file(repo_path, local_path)
        if success then
            success_count = success_count + 1
        end
    end

    print("Done. " .. success_count .. " out of " .. count .. " files synced.")

elseif args[1] == "sync" then
    local usage = "gitgud sync <repo path> <local path>"
    local repo_path = args[2] or error(usage)
    local local_path = args[3] or error(usage)

    repo_path = ensure_dotlua(repo_path)
    local_path = ensure_dotlua(local_path)

    storage[local_path] = repo_path
    update_storage()

    download_file(repo_path, local_path)

elseif args[1] == "delete" then
    local usage = "gitgud delete <local path>"
    local local_path = args[2] or error(usage)

    local_path = ensure_dotlua(local_path)

    storage[local_path] = nil
    update_storage()

    fs.delete(local_path)

elseif args[1] == "run" then
    local usage = "gitgud run <repo path> [args...]"
    local repo_path = args[2] or error(usage)

    repo_path = ensure_dotlua(repo_path)

    write("Downloading " .. repo_path .. "... ")
    local result, err = get(gitea_url(repo_path))
    if not result then
        print()
        printError(err)
    else
        print("OK")
    end

    local func, err = load(result, repo_path, "t", _ENV)
    if not func then
        printError(err)
        return
    end
    local success, err = pcall(func, select(3, ...))
    if not success then
        printError(err)
    end

else
    print("Unknown command " .. args[1])
    print("Try \"sync\", \"delete\" or \"run\"")

end