/*
* Copyright (c) 2025 Aldrik Ramaekers <aldrik.ramaekers@gmail.com>
* 
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
* 
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/

#include <stdlib.h>
#include <stdio.h>

#include "strops.hpp"
#include "ui.hpp"
#include "imgui.h"
#include "administration.hpp"
#include "locales.hpp"
#include "administration_writer.hpp"

extern void draw_contact_form(contact* buffer, bool viewing_only = false);

static contact company_info;

u32 tax_rate_count;
tax_rate* tax_rates = 0;

u32 cost_center_count;
cost_center* cost_centers = 0;

static int select_company_tab = 0;
static ai_service new_service;

void ui_destroy_settings()
{
    free(tax_rates);
    free(cost_centers);
}

void ui_setup_settings()
{
    select_company_tab = 1;
    company_info = administration_company_info_get();

    tax_rate_count = administration_tax_rate_count();
    tax_rates = (tax_rate*)malloc(tax_rate_count * sizeof(tax_rate));
    administration_tax_rate_get_all(tax_rates);

    cost_center_count = administration_cost_center_count();
    cost_centers = (cost_center*)malloc(cost_center_count * sizeof(cost_center));
    administration_cost_center_get_all(cost_centers);

    new_service = administration_get_ai_service();
}

static void ui_draw_vat_rates()
{
    static bool is_adding_item = false;
    static tax_rate new_tax_rate;

    static bool is_editing_item = false;
    static u32 editing_item_index = 0;

     if (ImGui::BeginTable("TableVatRates", 2, ImGuiTableFlags_Borders | ImGuiTableFlags_RowBg)) {

        ImGui::TableSetupColumn(localize("settings.vat.table.country"), ImGuiTableColumnFlags_WidthFixed, 220);
        ImGui::TableSetupColumn(localize("settings.vat.table.rates"));

        // Used to generate headers for each individual country.
        char prev_country[MAX_LEN_COUNTRY_CODE];
        prev_country[0] = 0;

        for (u32 i = 0; i < tax_rate_count; i++) {
            tax_rate c = tax_rates[i];

            // Set to false for shared rates.
            bool can_be_modified = false;

            // Check for fixed rates shared accross countries.
            if (strcmp(c.country_code, "00") == 0)
            {
                strops_copy(prev_country, c.country_code, 3);
                can_be_modified = false;     
            }
            // Generate headers per country.
            else if (strcmp(c.country_code, prev_country) != 0)
            {              
                strops_copy(prev_country, c.country_code, 3);

                // Empty row.
                ImGui::TableNextRow();
                ImGui::TableSetColumnIndex(0); ImGui::Text("");
                ImGui::TableSetBgColor(ImGuiTableBgTarget_CellBg, IM_COL32(69, 69, 69, 255));
                ImGui::TableSetColumnIndex(1); ImGui::Text("");
                ImGui::TableSetBgColor(ImGuiTableBgTarget_CellBg, IM_COL32(69, 69, 69, 255));

                ImGui::TableNextRow();

                char locale_buf[20];
                snprintf(locale_buf, sizeof(locale_buf), "country.%s", c.country_code);
                ImGui::TableSetColumnIndex(0); 
                ImGui::Text(localize(locale_buf));

                // If not adding an item already, show + button next to country name.
                if (!is_adding_item)
                {
                    ImGui::SameLine();
                    char btn_name[20];
                    snprintf(btn_name, sizeof(btn_name), "+##%d",i);
                    ImGui::PushStyleVar(ImGuiStyleVar_FramePadding, ImVec2(0,0));
                    if (ImGui::Button(btn_name, ImVec2(20,20))) {
                        is_adding_item = true;
                        is_editing_item = false;
                        new_tax_rate = administration_tax_rate_create_empty();
                        strops_copy(new_tax_rate.country_code, c.country_code, 3);
                    }
                    ImGui::PopStyleVar();
                }

                ImGui::TableSetColumnIndex(1); ImGui::Text("");
            }
            
            // Column 1: description of tax rate. Is only displayed on shared tax rates for clarity.
            ImGui::TableNextRow();
            ImGui::TableSetColumnIndex(0); 

            char category_code_desc[MAX_LEN_LONG_DESC];
            snprintf(category_code_desc, MAX_LEN_LONG_DESC, "taxcategory.%s", c.category_code);
            ImGui::Text(can_be_modified ? "" : localize(category_code_desc));
           
            
            // Column 2: When editing, show input for new rate. Else we display the stored rate and check for modify request.
            ImGui::TableSetColumnIndex(1);         
            if (is_editing_item && editing_item_index == i)
            {
                ImGui::InputFloat("##Rate", &new_tax_rate.rate, 1.0f, 5.0f, "%.2f");

                if (new_tax_rate.rate < 0.0f) new_tax_rate.rate = 0.0f;
                if (new_tax_rate.rate > 100.0f) new_tax_rate.rate = 100.0f;

                ImGui::SameLine();
                if (ImGui::Button(localize("form.save"))) {
                    is_editing_item = false;
                    is_adding_item = false;

                    administration_tax_rate_update(new_tax_rate);

                    ui_destroy_settings();
                    ui_setup_settings();
                }

                ImGui::SameLine();
                if (ImGui::Button(localize("form.cancel"))) {
                    is_editing_item = false;
                    is_adding_item = false;
                    memset(&new_tax_rate, 0, sizeof(new_tax_rate));
                }
            }
            else
            {
                ImGui::Text("%.2f%%", c.rate);
                
                if (can_be_modified && ImGui::IsItemHovered() && ImGui::IsMouseDoubleClicked(ImGuiMouseButton_Left))
                {
                    is_editing_item = true;
                    is_adding_item = false;
                    editing_item_index = i;
                    new_tax_rate = c;
                }
            }
            
            // When adding a new entry it is displayed at the bottom of the list of the country we are adding to.
            // Check for end of list (for last country in the list), or check if next country differs from current country.
            // If it is different we have reached the end of the list for the current country.
            if (i == tax_rate_count-1 || (i < tax_rate_count-1 && strcmp(tax_rates[i+1].country_code, c.country_code) != 0))
            {
                if (is_adding_item && strcmp(new_tax_rate.country_code, prev_country) == 0)
                {
                    ImGui::TableNextRow();
                    ImGui::TableSetColumnIndex(0); ImGui::Text("");
                    ImGui::TableSetColumnIndex(1);
                    ImGui::InputFloat("##Rate", &new_tax_rate.rate, 1.0f, 5.0f, "%.2f");

                    if (new_tax_rate.rate < 0.0f) new_tax_rate.rate = 0.0f;
                    if (new_tax_rate.rate > 100.0f) new_tax_rate.rate = 100.0f;

                    ImGui::SameLine();
                    if (ImGui::Button(localize("form.save"))) {
                        is_editing_item = false;
                        is_adding_item = false;

                        administration_tax_rate_add(new_tax_rate);

                        ui_destroy_settings();
                        ui_setup_settings();
                    }

                    ImGui::SameLine();
                    if (ImGui::Button(localize("form.cancel"))) {
                        is_editing_item = false;
                        is_adding_item = false;
                        memset(&new_tax_rate, 0, sizeof(new_tax_rate));
                    }
                }
            }
        }

        ImGui::EndTable();
    }
}

static void ui_draw_cost_centers()
{
    static bool is_adding_item = false;
    static cost_center new_cost_center;

    static bool is_editing_item = false;
    static u32 editing_item_index = 0;

    if (ImGui::BeginTable("TableCostCenters", 2, ImGuiTableFlags_Borders | ImGuiTableFlags_RowBg)) {

        ImGui::TableSetupColumn(localize("settings.costcenters.table.code"), ImGuiTableColumnFlags_WidthFixed, 140);
        ImGui::TableSetupColumn(localize("settings.costcenters.table.description"));

        for (u32 i = 0; i < cost_center_count; i++) {
            cost_center c = cost_centers[i];

            ImGui::TableNextRow();

            // Column 1: Code of cost center.
            ImGui::TableSetColumnIndex(0); ImGui::Text(c.code);

            // Column 2: When editing, show inputs for new description. Else show stored description and check for modify request.
            ImGui::TableSetColumnIndex(1);          
            if (is_editing_item && editing_item_index == i)
            {
                bool is_desc_valid = !(administration_cost_center_is_valid(new_cost_center) & A_ERR_MISSING_DESCRIPTION);
                if (!is_desc_valid) ImGui::PushStyleColor(ImGuiCol_FrameBg, IM_COL32(105, 43, 43, 255));
                ImGui::InputText("##Description", new_cost_center.description, IM_ARRAYSIZE(new_cost_center.description));
                if (!is_desc_valid) ImGui::PopStyleColor();

                if (!is_desc_valid) ImGui::BeginDisabled();
                ImGui::SameLine();
                if (ImGui::Button(localize("form.save"))) {
                    is_editing_item = false;
                    is_adding_item = false;

                    administration_cost_center_update(new_cost_center);

                    memset(&new_cost_center, 0, sizeof(new_cost_center));

                    ui_destroy_settings();
                    ui_setup_settings();
                }
                if (!is_desc_valid) ImGui::EndDisabled();

                ImGui::SameLine();
                if (ImGui::Button(localize("form.cancel"))) {
                    is_editing_item = false;
                    is_adding_item = false;
                    memset(&new_cost_center, 0, sizeof(new_cost_center));
                }
            }
            else
            {
                ImGui::Text(localize(c.description));

                if (ImGui::IsItemHovered() && ImGui::IsMouseDoubleClicked(ImGuiMouseButton_Left))
                {
                    is_editing_item = true;
                    is_adding_item = false;
                    editing_item_index = i;
                    new_cost_center = c;
                }
            }                 
        }

        // When adding a new item. Show inputs for code and description, check validity, and handle save/cancel.
        // Form for new entry is displayed at bottom of list.
        if (is_adding_item)
        {
            ImGui::TableNextRow();
            
            bool is_code_valid = !(administration_cost_center_is_valid(new_cost_center) & (A_ERR_CODE_EXISTS|A_ERR_MISSING_CODE));
            if (!is_code_valid) ImGui::PushStyleColor(ImGuiCol_FrameBg, IM_COL32(105, 43, 43, 255));
            ImGui::TableSetColumnIndex(0); ImGui::InputText("##Code", new_cost_center.code, IM_ARRAYSIZE(new_cost_center.code), 
                ImGuiInputTextFlags_CharsUppercase|ImGuiInputTextFlags_CharsNoBlank);
            if (!is_code_valid) ImGui::PopStyleColor();

            bool is_desc_valid = !(administration_cost_center_is_valid(new_cost_center) & A_ERR_MISSING_DESCRIPTION);
            if (!is_desc_valid) ImGui::PushStyleColor(ImGuiCol_FrameBg, IM_COL32(105, 43, 43, 255));
            ImGui::TableSetColumnIndex(1); ImGui::InputText("##Description", new_cost_center.description, IM_ARRAYSIZE(new_cost_center.description));
            if (!is_desc_valid) ImGui::PopStyleColor();

            bool can_save = is_code_valid && is_desc_valid;

            if (!can_save) ImGui::BeginDisabled();
            ImGui::SameLine();
            if (ImGui::Button(localize("form.create")))
            {
                is_adding_item = false;
                is_editing_item = false;
                administration_cost_center_add(new_cost_center);

                ui_destroy_settings();
                ui_setup_settings();
            }
            if (!can_save) ImGui::EndDisabled();

            ImGui::SameLine();
            if (ImGui::Button(localize("form.cancel"))) {
                is_adding_item = false;
                is_editing_item = false;
                memset(&new_cost_center, 0, sizeof(new_cost_center));
            }
        }

        ImGui::EndTable();
    }

    // If not adding a new item already, show create button at bottom of list.
    if (!is_adding_item && ImGui::Button(localize("form.create")))
    {
        new_cost_center = administration_cost_center_create_empty();
        is_adding_item = true;
        is_editing_item = false;
    }
}

static void ui_draw_services()
{   
     // AI service
    if (ImGui::CollapsingHeader(localize("settings.services.ai_service")))
    {
        // TODO: get this from iterator over ai_get_impl
        char* services[2] = {
            "OpenAI",
            "DeepSeek",
        };

        if (ImGui::BeginCombo(localize("settings.services.ai_service.provider"), services[new_service.provider]))
        {
            for (u32 n = 0; n < 2; n++)
            {
                bool is_selected = n == (uint32_t)new_service.provider;
                if (ImGui::Selectable(services[n], is_selected)) {
                    new_service.provider = (ai_provider)n;
                }
            }
            ImGui::EndCombo();
        }
             
        ImGui::InputTextWithHint(localize("settings.services.ai_service.pubkey"), localize("settings.services.ai_service.pubkey"), 
        new_service.api_key_public, sizeof(new_service.api_key_public));
        
        if (ImGui::Button(localize("form.save"))) {
            administration_set_ai_service(new_service); 
        }             
    }
}

void ui_draw_settings()
{
    if (ImGui::BeginTabBar("SettingsTabBar"))
    {
        if (ImGui::BeginTabItem(localize("settings.table.company"), nullptr, select_company_tab == 1 ? ImGuiTabItemFlags_SetSelected : 0))
        {
            select_company_tab = 0;
            draw_contact_form(&company_info);

            // Save button.
            bool can_save = administration_contact_is_valid(company_info) == A_ERR_SUCCESS;
            if (!can_save) ImGui::BeginDisabled();
            ImGui::Spacing();
            if (ImGui::Button(localize("form.save"))) {
                administration_company_info_set(company_info);
            }
            if (!can_save) ImGui::EndDisabled();

            ImGui::EndTabItem();
        }
        if (ImGui::BeginTabItem(localize("settings.table.vatrates")))
        {
            ui_draw_vat_rates();
            ImGui::EndTabItem();
        }
        if (ImGui::BeginTabItem(localize("settings.table.costcenters")))
        {
            ui_draw_cost_centers();
            ImGui::EndTabItem();
        }
        if (ImGui::BeginTabItem(localize("settings.table.services")))
        {
            ui_draw_services();
            ImGui::EndTabItem();
        }
        ImGui::EndTabBar();
    }
}