-- Leave empty for public repos, or add "your-token-here"
local GIT_TOKEN = ""

local GIT_OUTPUT_LOCATION = "/home"

-- Update config
local UPDATE_URL = "https://git.ejebring.com/eejebring/CC-tweaked-Gitea-Client/raw/branch/main/git.lua"
local GIT_FILE = "git.lua"

---@param str string
---@param comp string
function string.beginsWith(str, comp)
    local compLen = string.len(comp)
    local begining = string.sub(str, 0, compLen)
    return begining == comp
end

---@param str string
---@param comp string
function string.endsWith(str, comp)
    local reverseStr = string.reverse(str)
    local reverseComp = string.reverse(comp)
    return string.beginsWith(reverseStr, reverseComp)
end

---@param str string
---@param delimiter string
function string.split(str, delimiter)
    local returnTable = {}
    for k in string.gmatch(str, "([^" .. delimiter .. "]+)")
    do
        returnTable[#returnTable + 1] = k
    end
    return returnTable
end

local protocols = { "http://", "https://" }
local ending = ".git"
---@param url string
local function parseGiteaURL(url)
    ---@class urlinfo
    local urlInfo = {
        protocol = "",
        origin = "",
        owner = "",
        repo = "",
        branch = "main",
        treeUrl = "",
    }
    local lowerUrl = string.lower(url)
    if not string.endsWith(lowerUrl, ending) then error("A gitea link needs to end with " .. ending) end
    for _, proto in pairs(protocols) do
        if string.beginsWith(lowerUrl, proto) then
            urlInfo.protocol = proto
            break
        end
    end
    local urlLen = string.len(url)
    local protoLen = string.len(urlInfo.protocol)
    local endLen = string.len(ending)
    local cleaned = string.sub(url, protoLen + 1, urlLen - endLen)

    local urlParts = string.split(cleaned, "/")
    if not (#urlParts) == 3 then error("Unexpected link length.") end
    urlInfo.origin, urlInfo.owner, urlInfo.repo = urlParts[1], urlParts[2], urlParts[3]

    urlInfo.treeUrl =
        ("%s%s/api/v1/repos/%s/%s/git/trees/%s?recursive=1")
        :format(urlInfo.protocol, urlInfo.origin, urlInfo.owner, urlInfo.repo, urlInfo.branch)
    for k, v in pairs(urlInfo) do
        if v == "" or v == nil then
            error("Could not parse " .. k .. " from link.")
        end
    end
    print("treeUrl: ", urlInfo.treeUrl)
    return urlInfo
end

---@param urlInfo urlinfo
---@param path string
---@param target string
local function downloadFile(urlInfo, path, target)
    local url = ("%s%s/api/v1/repos/%s/%s/raw/%s/%s"):format(urlInfo.protocol, urlInfo.origin, urlInfo.owner,
        urlInfo.repo, urlInfo.branch, path)

    local req = { url = url }
    if GIT_TOKEN ~= "" then
        req.headers = { Authorization = "token " .. GIT_TOKEN }
    end

    local response, err = http.get(req)
    if not response then error("Failed to download: " .. path .. " due to: " .. err) end

    local data = response.readAll()
    response.close()

    local file, fileError = fs.open(target, "w")
    if file then
        file.write(data)
        file.close()
    else
        error("Could not download file '" .. target "' due to: " .. fileError)
    end
end

local function cloneRepo(url)
    local urlInfo = parseGiteaURL(url)
    print("Cloning: " .. urlInfo.owner .. "/" .. urlInfo.repo .. "@" .. urlInfo.branch)

    local req = { url = urlInfo.treeUrl }
    if GIT_TOKEN ~= "" then
        req.headers = { Authorization = "token " .. GIT_TOKEN }
    end

    local resp = http.get(req)
    if not resp then error("Cannot access repository. Check URL or token.") end
    local responseJSON = resp.readAll()
    resp.close()
    if not responseJSON then error("Response returned empty.") end

    local tree = textutils.unserializeJSON(responseJSON)
    if not tree then error("Response could not be unserialized") end

    local count = 0
    for _, node in ipairs(tree.tree) do
        if node.type == "blob" then
            local localPath = ("%s/%s/%s"):format(GIT_OUTPUT_LOCATION, urlInfo.repo, node.path)
            local dir = fs.getDir(localPath)

            if not fs.isDir(dir) then fs.makeDir(dir) end

            downloadFile(urlInfo, node.path, localPath)
            count = count + 1
        end
    end

    print(("Cloned %d files to %s/%s"):format(count, GIT_OUTPUT_LOCATION, urlInfo.repo))
end

local args = { ... }
if args[1] == "clone" and args[2] then
    cloneRepo(args[2])
elseif args[1] == "update" then
    local resp = http.get(UPDATE_URL)
    if not resp then error("Failed to download update.") end
    local code = resp.readAll()
    if not code then error("Recived empty response from server.") end
    local file = fs.open(GIT_FILE, "w+")
    if not file then error("Could not overwite " .. GIT_FILE) end
    file.write(code)
else
    print("Usage:")
    print("  git update")
    print("  git clone <full-gitea-url>")
    print("")
    print("Examples:")
    print('  git clone "https://gitea.example.com/user/myrepo"')
    --print('  git clone "https://gitea.example.com/user/myrepo/tree/main/path/to/file.lua"')
    print("")
    print("Set GIT_TOKEN variable above for private repos.")
end