// perf_tests — stress data_table con N filas (default 1M).
//
// Patron: el boton "Performance Tests" del QA panel llama run_perf_test(rows, frames),
// que prepara el backing storage sync (lento si N grande) y marca el state como
// "perf mode ON". Durante los siguientes `frames` renders, render_perf_tab()
// mide latency por frame y al terminar deja resultados en qa::counters().
#include "perf_tests.h"
#include "qa_state.h"
#include "data_table/data_table.h"
#include "core/logger.h"

#include <imgui.h>

#include <algorithm>
#include <chrono>
#include <cstdio>
#include <string>
#include <vector>

namespace tables_qa {

namespace {

// Estado estatico del perf test. Sobrevive entre frames hasta nueva run.
struct PerfState {
    bool                      active           = false;
    long long                 rows             = 0;
    int                       frames_target    = 0;
    int                       frames_measured  = 0;
    std::vector<double>       frame_times_ms;
    std::vector<std::string>  back;     // backing — puede ser N millones
    std::vector<const char*>  ptrs;
    data_table::State         dt;
};

PerfState& perf() { static PerfState s; return s; }

// Generador deterministico — mismo seed produce mismas filas.
void seed_synthetic(long long rows) {
    auto& p = perf();
    p.back.clear();
    // Para N filas con 6 columnas, necesitamos rows*6 strings.
    // Reservamos para evitar reallocs durante el push_back.
    p.back.reserve(static_cast<size_t>(rows * 6));

    char buf[64];
    const char* statuses[] = {"ok", "error", "running", "pending"};
    const char* langs[]    = {"go", "py", "cpp"};
    const int n_statuses = 4;
    const int n_langs    = 3;

    for (long long i = 0; i < rows; ++i) {
        // id
        std::snprintf(buf, sizeof(buf), "%lld", i + 1);
        p.back.emplace_back(buf);
        // name
        std::snprintf(buf, sizeof(buf), "item_%lld", i);
        p.back.emplace_back(buf);
        // status
        p.back.emplace_back(statuses[i % n_statuses]);
        // duration_ms — varia 50..7000
        std::snprintf(buf, sizeof(buf), "%lld", 50 + (i * 137) % 6950);
        p.back.emplace_back(buf);
        // lang
        p.back.emplace_back(langs[i % n_langs]);
        // value 0..10000
        std::snprintf(buf, sizeof(buf), "%lld", (i * 71) % 10000);
        p.back.emplace_back(buf);
    }

    qa::TabState dummy;
    p.ptrs.clear();
    p.ptrs.reserve(p.back.size());
    for (auto& s : p.back) p.ptrs.push_back(s.c_str());
}

} // anon

void run_perf_test(long long rows, int frames) {
    fn_log::log_info("perf_test: starting rows=%lld frames=%d", rows, frames);
    auto& p = perf();
    p.active          = true;
    p.rows            = rows;
    p.frames_target   = frames;
    p.frames_measured = 0;
    p.frame_times_ms.clear();
    p.frame_times_ms.reserve(static_cast<size_t>(frames));

    // Seed sync. Para 10M filas tarda varios segundos.
    auto t0 = std::chrono::steady_clock::now();
    seed_synthetic(rows);
    auto t1 = std::chrono::steady_clock::now();
    double seed_ms = std::chrono::duration<double, std::milli>(t1 - t0).count();

    auto& c = qa::counters();
    c.last_perf_rows         = rows;
    c.last_perf_seed_ms      = seed_ms;
    c.last_perf_frames       = 0;
    c.last_perf_render_ms_p50 = 0.0;
    c.last_perf_render_ms_p95 = 0.0;

    fn_log::log_info("perf_test: seeded rows=%lld in %.2f ms", rows, seed_ms);
}

void render_perf_tab() {
    auto& p = perf();

    if (!p.active) {
        ImGui::TextDisabled("No perf test active.");
        ImGui::TextDisabled("Open QA Control Panel and click " "Performance Tests" " to start.");
        return;
    }

    // KPI header
    auto& c = qa::counters();
    ImGui::Text("Active perf: rows=%lld   seed=%.1fms   frames_done=%d/%d",
                p.rows, c.last_perf_seed_ms, p.frames_measured, p.frames_target);
    if (p.frames_measured > 0) {
        ImGui::SameLine();
        ImGui::Text("   p50=%.2fms p95=%.2fms",
                    c.last_perf_render_ms_p50, c.last_perf_render_ms_p95);
    }
    ImGui::Separator();

    // Construir TableInput
    data_table::TableInput tbl;
    tbl.name    = "perf";
    tbl.headers = {"id", "name", "status", "duration_ms", "lang", "value"};
    tbl.types   = {
        data_table::ColumnType::Int,
        data_table::ColumnType::String,
        data_table::ColumnType::String,
        data_table::ColumnType::Float,
        data_table::ColumnType::String,
        data_table::ColumnType::Float,
    };
    tbl.cells = p.ptrs.data();
    tbl.rows  = static_cast<int>(p.rows);
    tbl.cols  = 6;

    // Renderers — ejercemos los caros (CategoricalChip + ColorScale + Duration).
    tbl.column_specs.resize(tbl.cols);
    for (int i = 0; i < tbl.cols; i++) tbl.column_specs[i].id = tbl.headers[i];
    tbl.column_specs[2].renderer = data_table::CellRenderer::CategoricalChip;
    tbl.column_specs[2].chips    = {
        {"ok", "#22c55e"}, {"error", "#ef4444"},
        {"running", "#f59e0b"}, {"pending", "#a3a3a3"},
    };
    tbl.column_specs[3].renderer          = data_table::CellRenderer::Duration;
    tbl.column_specs[3].duration_warn_ms  = 1000.0f;
    tbl.column_specs[3].duration_error_ms = 5000.0f;
    tbl.column_specs[4].renderer = data_table::CellRenderer::CategoricalChip;
    tbl.column_specs[4].chips    = {
        {"go",  "#3b82f6"}, {"py", "#22c55e"}, {"cpp", "#a855f7"},
    };
    tbl.column_specs[5].renderer    = data_table::CellRenderer::ColorScale;
    tbl.column_specs[5].range_min   = 0.0;
    tbl.column_specs[5].range_max   = 10000.0;
    tbl.column_specs[5].range_alpha = 0.30f;

    // Medir frame time
    ImGui::BeginChild("##perf_host", ImVec2(-1, -1));
    auto t0 = std::chrono::steady_clock::now();
    data_table::render("##perf_tbl", {tbl}, p.dt, nullptr, true);
    auto t1 = std::chrono::steady_clock::now();
    ImGui::EndChild();

    if (p.frames_measured < p.frames_target) {
        double ms = std::chrono::duration<double, std::milli>(t1 - t0).count();
        p.frame_times_ms.push_back(ms);
        p.frames_measured++;

        if (p.frames_measured == p.frames_target) {
            // Compute p50 / p95
            std::vector<double> sorted = p.frame_times_ms;
            std::sort(sorted.begin(), sorted.end());
            size_t n = sorted.size();
            double p50 = sorted[n / 2];
            double p95 = sorted[(n * 95) / 100];
            c.last_perf_render_ms_p50 = p50;
            c.last_perf_render_ms_p95 = p95;
            c.last_perf_frames        = p.frames_measured;
            fn_log::log_info("perf_test DONE rows=%lld frames=%d p50=%.2fms p95=%.2fms",
                             p.rows, p.frames_measured, p50, p95);
        }
    }
}

} // namespace tables_qa