---==================================================================================================================---
---                                                                                                                  ---
---    Original Author(s) : NLTP_ASHES                                                                               ---
---    Edited : N/A                                                                                                  ---
---    Date : 19/05/2023                                                                                             ---
---    License : Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)           ---
---                                                                                                                  ---
---    Script used to spawn NPCs that should permanently exist in the world (mostly if not exclusively traders).     ---
---                                                                                                                  ---
---    To add a new NPC to the system, add a new line in the squads_to_spawn table, as follows :                     ---
---                                                                                                                  ---
---    { sec="<squad_section>", sid="<story_id>", smart="<spawn_smart_name>" },                                      ---
---                                                                                                                  ---
---    Where :                                                                                                       ---
---     - <squad_section> : section of the squad that needs to be spawned in;                                        ---
---     - <story_id> : story id of the squad that needs to be spawned in;                                            ---
---     - <spawn_smart_name> : name of the smart where the squad should be spawned at;                               ---
---                                                                                                                  ---
---==================================================================================================================---

-- ---------------------------------------------------------------------------------------------------------------------
-- Constants, global variables and imported functions
-- ---------------------------------------------------------------------------------------------------------------------

-- Imported functions
local dbg_printf                = western_goods_utils.dbg_printf

-- Constants
local squads_to_spawn = {
    ["stalker_western_goods_trader_squad"] = { sid="stalker_western_goods_trader_squad", smart="pri_a18_smart_terrain" },
    ["stalker_oleksandr_chernenko_squad"] = { sid="stalker_oleksandr_chernenko_squad", smart="gar_smart_terrain_6_3" },
}

local squads_relations = {
    ["stalker_western_goods_trader_squad"] = "neutral",
    ["stalker_oleksandr_chernenko_squad"] = "neutral",
    ["stalker_danylo_chernenko_squad"] = "neutral",
    ["western_goods_act_2_task_2_bandit_1_squad"] = "enemy",
    ["western_goods_act_2_task_2_bandit_2_squad"] = "enemy",
}

-- ---------------------------------------------------------------------------------------------------------------------
-- General functions
-- ---------------------------------------------------------------------------------------------------------------------

--- Function used to spawn the permanent NPCs on the map.
--- @return nil
function spawn_squads()
    for section,data in pairs(squads_to_spawn) do
        local squad_se = western_goods_utils.server_object_by_sid(data.sid)
        if not squad_se then
            squad_se = western_goods_utils.spawn_story_squad(section, nil, SIMBOARD.smarts_by_names[data.smart])
            dbg_printf("[WG] Permanent NPCs | Created %s(%s) at %s", section, squad_se.id, data.smart)
        else
            dbg_printf("[WG] Permanent NPCs | Squad %s(%s) already exists", squad_se:section_name(), squad_se.id)
        end
    end
end

--- Function used to force some NPCs to be neutral to and with everyone.
--- This function is fired by 'on_enemy_eval' callback.
--- @param obj game_object
--- @param enemy game_object
--- @param flags table
--- @return nil
function eval_ignore_npcs(obj,enemy,flags)
    -- Skip mutants
    if IsMonster(obj) or IsMonster(enemy) then
        return
    end

    -- Get squad
    local squad_obj = western_goods_utils.get_squad_of(obj)
    local squad_enemy = western_goods_utils.get_squad_of(enemy)

    -- Get squad relation (if any)
    local relation_obj = squad_obj and squads_relations[squad_obj:section_name()]
    local relation_enemy = squad_enemy and squads_relations[squad_enemy:section_name()]

    -- Skip unaffected squads
    if (not relation_obj) and (not relation_enemy) then
        return
    end

    -- Override eval
    if relation_obj == "neutral" or relation_enemy == "neutral" then
        flags.override = true
        flags.result = false
        return
    elseif relation_obj == "enemy" or relation_enemy == "enemy" then
        flags.override = true
        flags.result = true
        return
    end
end

-- ---------------------------------------------------------------------------------------------------------------------
-- Oleksandr Chernenko functions
-- ---------------------------------------------------------------------------------------------------------------------

--- Function used to determine if Oleksandr Chernenko can show the Flea Market dialog.
--- @param actor game_object
--- @param npc game_object
--- @param flags table
function oleksandr_can_show_flea(actor,npc,flags)
    if npc:section() == "stalker_oleksandr_chernenko" then
        flags.result = western_goods_utils.has_info("western_goods_oleksandr_chernenko_meet_over")
    end
end

-- ---------------------------------------------------------------------------------------------------------------------
-- Williams Heades functions
-- ---------------------------------------------------------------------------------------------------------------------

if western_goods_core.is_barter_ui_installed() then
    --- Function used to initiate the Barter UI.
    --- @return nil
    function ashes_barter()
        utils_obj.play_sound("interface\\inv_open")
        barter_ui.start()
    end
end

--- Function used to determine if Williams Heades can show the EUR/USD trade dialog.
--- @param actor game_object
--- @param npc game_object
--- @param flags table
function ashes_can_show_trade(actor,npc,flags)
    if npc:section() == "stalker_western_goods_trader" then
        flags.result = western_goods_utils.has_info("western_goods_trader_first_meet_over")
    end
end

-- ---------------------------------------------------------------------------------------------------------------------
-- Crew Member functions
-- ---------------------------------------------------------------------------------------------------------------------

if western_goods_core.is_barter_ui_installed() then
    --- Function used to initiate the Barter UI.
    --- @return nil
    function crew_member_barter()
        utils_obj.play_sound("interface\\inv_open")
        barter_ui.start()
    end
end

-- ---------------------------------------------------------------------------------------------------------------------
-- Callbacks registration
-- ---------------------------------------------------------------------------------------------------------------------

--- Function used to register callbacks.
--- @return nil
function on_game_start()
    RegisterScriptCallback("on_enemy_eval", eval_ignore_npcs)
    RegisterScriptCallback("actor_on_first_update", spawn_squads)
    RegisterScriptCallback("western_goods_flea_on_dialog", oleksandr_can_show_flea)
    RegisterScriptCallback("western_goods_trade_eur_usd_on_dialog", ashes_can_show_trade)
end