--[[
Illarion Server

This program is free software: you can redistribute it and/or modify it under
the terms of the GNU Affero 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 Affero General Public License for more
details.

You should have received a copy of the GNU Affero General Public License along
with this program.  If not, see <http://www.gnu.org/licenses/>.
]]
-- Collection of helper functions for the handling of characters

local common = require("base.common")
local pulsegwynt = require("magic.nature.effects.pulsegwynt")
local testing = require("base.testing")

local M = {}

local HITPOINTS = "hitpoints"

--- Get the current hitpoints of the character
-- @param User the character that is queried
-- @return the hitpoints of the character
function M.GetHP(User)
    return User:increaseAttrib(HITPOINTS, 0)
end

--- Change the hitpoints value of a character.
-- @param User The characters that receives the hitpoints change.
-- @param Value The value the hitpoints are changed by.
-- @return true in case the character is alive after the change of the hitpoints
function M.ChangeHP(defender, valueChange)

    local partner, partnerDamage

    if valueChange < 0 and valueChange ~= -10000 then -- The character is taking damage, not being healed and it isnt an instakill

        valueChange, partner, partnerDamage = pulsegwynt.impactOnDamageTaken(defender, valueChange)
        -- If bonded with someone via nature magics deepweave spell Pulsegwynt, they take part of the damage for you
        if partner then
            partner:increaseAttrib(HITPOINTS, partnerDamage)
        end
    end

    -- A bond is broken if you or your partners health is reduced to 20% or lower
    if partner and (M.GetHP(partner) < pulsegwynt.healthLimit or M.GetHP(defender)-valueChange < pulsegwynt.healthLimit) then
        pulsegwynt.breakBond(defender, partner)
    end

    if testing.active and valueChange < 0 and valueChange ~= -10000 then
        defender:talk(Character.say,"#me takes "..-valueChange.." damage.", "#me takes "..-valueChange.." damage.")
        if partner then
            partner:talk(Character.say,"#me takes "..-partnerDamage.." damage.", "#me takes "..-partnerDamage.." damage.")
        end
    end

    return defender:increaseAttrib(HITPOINTS, valueChange) > 0
end;

--- Check if a character would surive if a amount of hitpoints get reduced
-- @param User The character that is tested
-- @param Value The value of hitpoints that are supposed to be reduced
-- @return true in case the character would survive
function M.WouldDie(User, Value)
    return M.GetHP(User) <= Value;
end;

--- Check if a character is dead.
-- @param User the character to check
-- @return true in case the character is dead
function M.IsDead(User)
    return M.GetHP(User) == 0
end

--- Check if the character is at the brink of death. Means that the character
-- has only one hitpoint left.
-- @param User The character to check
-- @return true in case the character is at the brink of death
function M.AtBrinkOfDeath(User)
    return M.WouldDie(User, 1);
end;

--- Bring a character to the brink of death. Means that he has only one hitpoint
-- left.
-- @param User The character to bring to the brink of death
function M.ToBrinkOfDeath(User)
    M.ChangeHP(User, 1 - M.GetHP(User));
end;

local overTimeLTEs = {1, 3, 9, 10} -- health, mana and stamina drains over time need to be removed on death, no matter what the killing blow is

local recentlyKilled = {}

--- Kill a character.
-- @param User The character to kill
-- @return true in case the player was killed successfully
function M.Kill(user)

    local timeStamp = world:getTime("unix")

    for _, lte in pairs(overTimeLTEs) do
        local foundEffect = user.effects:find(lte)
        if foundEffect then
            user.effects:removeEffect(lte)
        end
    end

    if recentlyKilled[user.id] and recentlyKilled[user.id]+5 >= timeStamp then --It's been 5 or less seconds since this character was killed
        return --ensures that if a DoT was applied right after or in the same blow as a killing blow, it wont reskill you
    end

    common.TalkNLS(user, Character.say,"#me geht tödlich getroffen zu Boden.","#me goes down, fatally injured.")
    M.ChangeHP(user, -10000)
    recentlyKilled[user.id] = timeStamp
    return true
end

function M.WasKilledRecently(user)

    local timeStamp = world:getTime("unix")

    if recentlyKilled[user.id] and recentlyKilled[user.id]+5 >= timeStamp then
        return true
    end

    return false
end

--- Change the movepoints of a character by the value handed over.
-- @param User The character thats movepoints are supposed to change
-- @param Value The amount of movepoints that are added
function M.ChangeMovepoints(User, Value)
    User.movepoints = User.movepoints + Value;
end;

--- Change the fighting points of a character by the value handed over.
-- @param User The character thats fightingpoints are supposed to change
-- @param Value The amount of fightingpoints that are added
-- @info This is currently set to change the movepoints also because the
--          fighting points do not seem to work on the current server
function M.ChangeFightingpoints(User, Value)
    User.fightpoints = User.fightpoints + Value;
end;

--- Check if the character is a player character.
-- @param User The character to check
-- @return true in case the character is a player character
function M.IsPlayer(User)
    return User:getType() == Character.player;
end;

-- Kills immediately after a defined period of time
-- @param Character The character (e.g. summoned monster) supposed to die
-- @param deathAfter The period of time after which the character dies in 1/10 sec
-- @param deathGfx The GFX shown on the characters' death, nil for no GFX
-- @param deathSound The sound played on characters' death, nil for no sound
-- @param blood Boolean determining if blood is dropped or not
function M.DeathAfterTime(Character,deathAfter,deathGfx,deathSound,blood)
    local find = Character.effects:find(36)
    if find then
        return
    else
        local myEffect = LongTimeEffect(36,deathAfter)
        if deathGfx ~= nil then
            myEffect:addValue("deathGfx",deathGfx)
        end
        if deathSound ~= nil then
            myEffect:addValue("deathSound",deathSound)
        end
        if blood then
            myEffect:addValue("blood",1)
        end
        Character.effects:addEffect(myEffect)
    end
end

-- Get a string that is nicely usable for a character reference in the logfile
-- @param character the character
-- @return the reference string to the character for the logfile
function M.LogText(character)
    return string.format("%s (%u)", character.name, character.id);
end

return M