blips_server.lua

--[[
            LiveMap - A LiveMap for FiveM servers
              Copyright (C) 2017  Jordan Dalton

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program in the file "LICENSE".  If not, see <http://www.gnu.org/licenses/>.
]]

--[[
    When the client has generated the blips, this is called to save them.
    @param blipTable A array that contains all the blips to save
]]
RegisterServerEvent("livemap:blipsGenerated")

--[[
    Adds a blip to the blips that the UI can see (will be saved)
    @param blip A table that represents a blip.
    Only the host of the session can use this event.

    A blip follows the format:
    {
        sprite = Number (required)

        pos = Table (required){
            x = Float (required)
            y = Float (required)
            z = Float (required)
        }

        name = String (optional)
        description = String (optional)
    }

    sprite is the "spriteId" used when creating a blip.
    x,y,z represents the position of the blip (rounded to 2dp) and is stored inside "pos"
    name is the name of the blip shown on the UI
    desscription is a description of what the blip does, shown on UI
]]
RegisterServerEvent("livemap:AddBlip")

--[[
    Updates the information that is associated with a blip.
    Only the host of the session can use this event.

    @param blip A table that represents a blip (see the above format)

    Note: You cannot change the "sprite", "x", "y", "z" properties of the blip
]]
RegisterServerEvent("livemap:UpdateBlip")

RegisterServerEvent("livemap:RemoveClosestBlip")
RegisterServerEvent("livemap:RemoveBlip")



-- An array of blips that we have. This is encoded into JSON and sent over HTTP (when requested)
local blips = {}

-- Set this to the player who did the "blips generate" command. Should stop
-- randomers triggering the event :)
local playerWhoGeneratedBlips = nil

--[[
    ===================================
    =           Functions             =
    ===================================
]]

--[[
    Checks to see if the "blips" array is empty.

    @returns boolean True if the array is empty, False otherwise
]]
function blipsIsEmpty()
    for _, _ in pairs(blips) do
        return false
    end
    return true
end

--[[
    Checks if the "blips" array contains a certain blip.

    @param id The sprite ID of the blip
    @param x The x coordinate of the blip (rounded to 2dp)
    @param y The y coordinate of the blip (rounded to 2dp)
    @param z The z coordinate of the blip (rounded to 2dp)

    @return int The index that the blip is found at, -1 if not found.
]]
function blipsContainsBlip(id, x, y, z)
    if blips[id] == nil then
        return -1
    end

    for k,v in ipairs(blips[id]) do
        if v.pos.x == x and v.pos.y == y and v.pos.z == z then
            return k
        end
    end

    return -1
end

--[[
    Sends the encoded "blips" array to the client requesting it
    If no blips, an error is sent instead

    @param res The result object that can be sent data
]]
function sendBlips(res)
    if not blipsIsEmpty() then
        res.send(json.encode(blips))
    else
        res.send(json.encode({
            error = "blip cache is empty"
        }))
    end
end

--[[
    Saves the "blips" array to a file on the server.
    The filename is set in the server.cfg file with the convar `blip_file`
]]
function saveBlips()
    if blipsIsEmpty() then
        print("Blips are empty... No need to save")
        return
    end

    local blipFile = GetConvar("blip_file", "server/blips.json")
    local saved = SaveResourceFile(GetCurrentResourceName(), blipFile, json.encode(blips, {indent = true}), -1)

    if not saved then
        print("LiveMap couldn't save the blips to file.. Maybe the directory isn't writable?")
    end

end

--[[
    ===================================
    =             Events              =
    ===================================
]]


AddEventHandler("livemap:AddBlip", function(blip)

    if not blip["sprite"] or blip["sprite"] == nil then
        -- We don't have a sprite id... we can't save it :(
        print("LiveMap Error: AddBlip cannot run because no sprite wasn't supplied.")
        return
    end

    if not blip["pos"] or blip["pos"] == nil then
        print("LiveMap Error:: AddBlip cannot run because the pos wasn't supplied.")
        return
    end

    local id = tostring(blip["sprite"])

    blip["sprite"] = nil

    -- Conveert coordinates to 2dp
    blip["pos"].x = tonumber(string.format("%.2f", blip["pos"].x))
    blip["pos"].y = tonumber(string.format("%.2f", blip["pos"].y))
    blip["pos"].z = tonumber(string.format("%.2f", blip["pos"].z))

    if blipsContainsBlip(id, blip.pos.x, blip.pos.y, blip.pos.z) == -1 then
        if blips[id] == nil then
            blips[id] = {}
        end

        table.insert(blips[id], blip)
        TriggerEvent("livemap:internal_AddBlip", id, blip)
        print("Sending addBlip for " .. id)

    else
        print("Blip already exists at " .. blip.pos.x .. "," .. blip.pos.y .. "," .. blip.pos.z)
    end
end)

AddEventHandler("livemap:UpdateBlip", function(blip)

    if not blip["sprite"] or blip["sprite"] == nil then
        -- We don't have a sprite id... we can't save it :(
        print("LiveMap Error: UpdateBlip cannot run because no sprite wasn't supplied.")
        return
    end

    if not blip["pos"] or blip["pos"] == nil then
        print("LiveMap Error:: UpdateBlip cannot run because the pos wasn't supplied.")
        return
    end

    local id = tostring(blip["sprite"])

    blip["sprite"] = nil

    blip["pos"].x = tonumber(string.format("%.2f", blip["pos"].x))
    blip["pos"].y = tonumber(string.format("%.2f", blip["pos"].y))
    blip["pos"].y = tonumber(string.format("%.2f", blip["pos"].y))

    local index = blipsContainsBlip(id, blip.pos.x, blip.pos.y, blip.pos.z)

    if index ~= -1 then
        blips[id][index] = blip

        TriggerEvent("livemap:internal_UpdateBlip", id, blip)

    else
        -- Blip doesn't exist, add it?
        if blips[id] == nil then
            blips[id] = {}
        end

        table.insert(blips[id], blip)

        TriggerEvent("livemap:internal_AddBlip", id, blip)

    end
end)

AddEventHandler("livemap:RemoveBlip", function(blip)

    if not blip["sprite"] or blip["sprite"] == nil then
        -- We don't have a sprite id... we can't save it :(
        print("LiveMap Error: RemoveBlip cannot run because no sprite wasn't supplied.")
        return
    end

    if not blip["pos"] or blip["pos"] == nil then
        print("LiveMap Error:: RemoveBlip cannot run because the pos wasn't supplied.")
        return
    end

    local id = tostring(blip["sprite"])

    blip["sprite"] = nil

    blip["pos"].x = tonumber(string.format("%.2f", blip["pos"].x))
    blip["pos"].y = tonumber(string.format("%.2f", blip["pos"].y))
    blip["pos"].y = tonumber(string.format("%.2f", blip["pos"].y))

    local index = blipsContainsBlip(id, blip.pos.x, blip.pos.y, blip.pos.z)

    if index == -1 then
        print("LiveMap Error: Cannot remove blip as it isn't in the table")
    else
        blips[id][index] = nil
        TriggerEvent("livemap:RemoveBlip", id, blip)
    end
end)

function getDistanceBetween(p1, p2)
    -- Apparently math.pow doesn't exist (nil value)
    local x = (p2.x - p1.x) * (p2.x - p1.x)
    local y = (p2.y - p1.y) * (p2.y - p1.y)
    local z = (p2.z - p1.z) * (p2.z - p1.z)

    -- sqrt works though!
    return math.sqrt(x + y + z)
end

AddEventHandler("livemap:RemoveClosestBlip", function(playerPos)
    local currentClosest = nil
    local sprite = nil
    local currentDistance = 999999

    for spriteId, blipArray in pairs(blips) do
        for _, blip in pairs(blipArray) do
            local distance = getDistanceBetween(playerPos, blip.pos)

            if (distance < currentDistance) then
                currentDistance = distance
                currentClosest = blip
                sprite = spriteId
            end

        end
    end

    if currentClosest == nil then
        -- No blips at all?
        return
    end

    print("Removing closest blip ("..sprite..") located at: " .. currentClosest.pos.x .. ", " .. currentClosest.pos.y .. ", " .. currentClosest.pos.z)

    local index = blipsContainsBlip(sprite, currentClosest.pos.x, currentClosest.pos.y, currentClosest.pos.z)

    if index == -1 then
        print("LiveMap Error: Umm... The closest blip doesn't have an index.. Something seriously wrong here!!!")
    else
        blips[sprite][index] = nil
        TriggerEvent("livemap:internal_RemoveBlip", sprite, currentClosest)
    end

end)


AddEventHandler("livemap:blipsGenerated", function(blipTable)
    local id = GetPlayerIdentifier(source, 0)

    if playerWhoGeneratedBlips == nil or playerWhoGeneratedBlips ~= id then
        print("playerWhoGeneratedBlips was incorrect.. Maybe \"" .. id .. "\" triggered the event themselves?\nEither way, I'm not doing it..")
        return
    end

    blips = blipTable

    saveBlips()
end)

AddEventHandler("onResourceStop", function(name)
    if name == GetCurrentResourceName() then
        saveBlips() -- Make sure the blips file is saved
    end
end)

AddEventHandler("onResourceStart", function(name)
    if name == GetCurrentResourceName() then
        local blipFile = GetConvar("blip_file", "server/blips.json")
        local blipData = LoadResourceFile(GetCurrentResourceName(), blipFile)

        if blipData then
            blips = json.decode(blipData)

            -- Update all the old positions to use the new one :)
            for spriteId, blipArray in pairs(blips) do
                for _, blip in pairs(blipArray) do
                    if not blip["pos"] then
                        blip.pos = {x=blip.x, y=blip.y, z=blip.z}
                        blip.x, blip.y, blip.z = nil,nil,nil
                    end
                end
            end

            print("loaded blip cache from file")
        end
    end
end)

AddEventHandler('playerDropped', function()
    local id = GetPlayerIdentifier(source, 0)
    TriggerEvent("livemap:internal_RemovePlayer", id)
end)

--[[
    ===================================
    =              Misc               =
    ===================================
]]

--[[
    Register a command and can be used in-game by an admin to generate the inital
        set of blips.

]]
RegisterCommand("blips", function(source, args, rawCommand)
    local playerId = GetPlayerIdentifier(source, 0)
    if args[1] == "generate" then
        print("Generating blips using the in-game native: Player " .. playerId .. " is generating (I hope you know them)")
        playerWhoGeneratedBlips = playerId

        TriggerClientEvent("livemap:getBlipsFromClient", source)

        return
    end

end, true)

--[[
    Handle HTTP requests. Mainly used for getting the blips via ajax from the UI
]]
SetHttpHandler(function(req, res)
	local path = req.path

    -- Restrict the origin if set, otherwise allow everyone
    res.writeHead(200, { ["Access-Control-Allow-Origin"] = GetConvar("livemap_access_control", "*")} )

    if path == "/blips" or path == "/blips.json" then
        return sendBlips(res)
    end

    return res.send(json.encode({
        error = "path \"" .. path .."\" not found"
    }))
end)