#include "tui/tui.hpp"
#include "tui/tui_helpers.hpp"

#include "system/analysis.hpp"
#include "system/connect.hpp"
#include "system/modules.hpp"
#include "system/nets.hpp"
#include "system/parts.hpp"
#include "system/pins.hpp"
#include "system/signals.hpp"
#include "system/system.hpp"

#include <ftxui/component/component.hpp>
#include <ftxui/dom/elements.hpp>

#include <algorithm>
#include <map>
#include <unordered_set>
#include <vector>

using namespace ftxui;

namespace {

// Two-column key/value row, fixed-width key so columns line up.
Element kv(const std::string &k, const std::string &v) {
    return hbox({
        text("  " + k) | dim | size(WIDTH, EQUAL, 16),
        text(v),
    });
}

}  // namespace

Component Tui::BuildDashboardScreen() {
    return Renderer([this] {
      auto title = hbox({
          text(" essim ") | bold,
          text("→ ") | dim,
          text("dashboard") | bold,
          text("  — system overview at a glance") | dim,
      });

      Element early_help = RenderHelpPanel("dashboard", {
          {"c",      "console"},
          {"a",      "analyze"},
          {"h",      "help screen"},
          {"q",      "quit"},
          {"Ctrl-P", "palette"},
      });

      if (!sys) {
          return vbox({
              title,
              separator(),
              hbox({
                  vbox({
                      text("  no system loaded — run 'new' or 'restore <file>'") | dim,
                      text("  (press 'c' for the console, or Ctrl-P for the palette)") | dim,
                      filler(),
                  }) | flex,
                  separator(),
                  early_help,
              }) | flex,
          }) | border;
      }

      // ---- counters ----
      int n_modules = (int)sys->modules()->size();
      int n_parts = 0, n_signals = 0;
      for (auto &mkv : *sys->modules()) {
          n_parts   += (int)mkv.second->size();
          n_signals += (int)mkv.second->signals->size();
      }
      int n_conn = (int)sys->connections()->size();

      // ---- verify-style health (recomputed; cheap on realistic sizes) ----
      int n_role_mismatches = 0, n_typed_pins = 0;
      for (auto &mkv : *sys->modules())
          for (auto &pkv : *mkv.second) {
              Part *prt = pkv.second;
              if (prt->connector_type.empty()) continue;
              for (auto &nkv : *prt) {
                  Pin *pin = nkv.second;
                  ++n_typed_pins;
                  SignalType expected = pin->expected_signal_type;
                  if (expected == SignalType::Other) continue;
                  Signal *s = pin->signal();
                  SignalType actual = s ? s->type : SignalType::Other;
                  if (actual != expected) ++n_role_mismatches;
              }
          }

      auto nets = compute_all_nets(sys.get());
      int n_bridged = 0, n_inconsistent = 0;
      for (const auto &n : nets) {
          if (n.members.size() < 2) continue;
          ++n_bridged;
          SignalType dom;
          if (!net_type_consistent(n, dom)) ++n_inconsistent;
      }

      // ---- NC orphan summary (matches verify pass 3) ----
      std::unordered_set<Pin *> bridged_pins;
      for (auto &ckv : *sys->connections())
          for (auto &wp : ckv.second->pin_map) {
              if (wp.first)  bridged_pins.insert(wp.first);
              if (wp.second) bridged_pins.insert(wp.second);
          }
      int orph_imported = 0, orph_dropped = 0;
      // Per-module list of dropped-singleton pins, for the detail rows below
      // the NC health line. The signal name is gone (the Signal object was
      // deleted by `drop_singleton_signals`), but the pin's full path is
      // enough to locate it in `explore`.
      std::map<std::string, std::vector<std::string>> dropped_by_module;
      for (auto &mkv : *sys->modules())
          for (auto &pkv : *mkv.second)
              for (auto &nkv : *pkv.second) {
                  Pin *pin = nkv.second;
                  if (pin->signal() || bridged_pins.count(pin)) continue;
                  if (pin->nc_origin == NcOrigin::ImportedUnconnected) {
                      ++orph_imported;
                  } else if (pin->nc_origin == NcOrigin::DroppedSingleton) {
                      ++orph_dropped;
                      dropped_by_module[mkv.first].push_back(
                          pkv.first + "/" + nkv.first);
                  }
              }

      auto health_line = [](bool ok, const std::string &s) {
          return hbox({
              text(ok ? "  ✓ " : "  ⚠ ") | (ok ? color(Color::Green) : color(Color::Yellow)),
              text(s),
          });
      };

      Elements health_rows;
      health_rows.push_back(health_line(n_role_mismatches == 0,
          "verify:  " + std::to_string(n_role_mismatches)
          + " pin-role mismatch(es) over " + std::to_string(n_typed_pins)
          + " typed pin(s)"));
      health_rows.push_back(health_line(n_inconsistent == 0,
          "nets:    " + std::to_string(n_inconsistent) + " inconsistent over "
          + std::to_string(n_bridged) + " bridged (" + std::to_string(nets.size())
          + " total)"));
      int orph_total = orph_imported + orph_dropped;
      health_rows.push_back(health_line(orph_total == 0,
          "NC:      " + std::to_string(orph_total) + " orphan pin(s) ("
          + std::to_string(orph_imported) + " imported, "
          + std::to_string(orph_dropped) + " dropped)"));

      // ---- analysis summary ----
      AnalysisReport rep = analyze_system(sys.get());
      int n_diff = 0, n_diff_bus = 0, n_bus = 0;
      for (const auto &g : rep.groups) {
          if (g.kind == GroupKind::DiffPair) ++n_diff;
          else if (g.kind == GroupKind::DiffBus) ++n_diff_bus;
          else if (g.kind == GroupKind::Bus) ++n_bus;
      }

      // ---- per-module table ----
      std::vector<std::string> mod_names;
      for (auto &mkv : *sys->modules()) mod_names.push_back(mkv.first);
      std::sort(mod_names.begin(), mod_names.end(), NaturalLess);
      size_t maxw = 1;
      for (const auto &n : mod_names) maxw = std::max(maxw, n.size());
      Elements mod_rows;
      for (const auto &name : mod_names) {
          Module *m = sys->modules()->get(name);
          int total = (int)m->size();

          // Group parts by connector_type so the table answers "which type
          // is on which part?" rather than just "how many are typed?".
          std::map<std::string, std::vector<std::string>> by_type;
          for (auto &pkv : *m)
              if (!pkv.second->connector_type.empty())
                  by_type[pkv.second->connector_type].push_back(pkv.first);

          mod_rows.push_back(hbox({
              text("  " + name + std::string(maxw - name.size(), ' '))
                  | size(WIDTH, EQUAL, (int)maxw + 4),
              text(std::to_string(total) + " part(s)") | size(WIDTH, EQUAL, 14),
              text(std::to_string(m->signals->size()) + " signal(s)"),
          }));

          // Power-signal breakdown for this module — same classification as
          // the analyze screen so the dashboard summary stays consistent.
          int n_pwr_ok = 0, n_pwr_suspect = 0, n_gnd = 0;
          for (auto &skv : *m->signals) {
              Signal *s = skv.second;
              SignalType named = infer_signal_type(s->name);
              if (named == SignalType::GndShield && s->type == SignalType::GndShield) ++n_gnd;
              else if (named == SignalType::Power && s->type == SignalType::Power) ++n_pwr_ok;
              else if (named == SignalType::Power && s->type == SignalType::Other) ++n_pwr_suspect;
          }
          if (n_pwr_ok + n_pwr_suspect + n_gnd > 0) {
              std::string label = "power: " + std::to_string(n_pwr_ok)
                                + " confirmed, " + std::to_string(n_pwr_suspect)
                                + " suspect   gnd: " + std::to_string(n_gnd);
              auto el = text("      " + label);
              if (n_pwr_suspect > 0) el = el | color(Color::Yellow);
              mod_rows.push_back(el);
          }

          if (by_type.empty()) {
              mod_rows.push_back(hbox({
                  text("      "),
                  text("(no connector types assigned)") | dim,
              }));
          } else {
              for (auto &tkv : by_type) {
                  std::sort(tkv.second.begin(), tkv.second.end(), NaturalLess);
                  std::string parts_csv;
                  for (size_t i = 0; i < tkv.second.size(); ++i) {
                      if (i) parts_csv += ", ";
                      parts_csv += tkv.second[i];
                  }
                  mod_rows.push_back(hbox({
                      text("      "),
                      text(tkv.first) | bold,
                      text(": "),
                      text(parts_csv),
                  }));
              }
          }
      }

      // Flatten the dashboard into a list of lines so we can scroll it as a
      // whole when the content overflows. The pattern mirrors the shell's
      // scrollback: pick one focused line and wrap in `yframe`.
      Elements lines;
      lines.push_back(text("  Overview") | bold);
      lines.push_back(hbox({
          vbox({
              kv("Modules",     std::to_string(n_modules)),
              kv("Parts",       std::to_string(n_parts)),
          }) | flex,
          vbox({
              kv("Signals",     std::to_string(n_signals)),
              kv("Connections", std::to_string(n_conn)),
          }) | flex,
      }));
      lines.push_back(separator());
      lines.push_back(text("  Health") | bold);
      for (auto &h : health_rows) lines.push_back(std::move(h));
      // Detail rows for the dropped-singleton NCs. Imported NCs are not
      // expanded — they were already explicit in the netlist. Dropped NCs
      // come from a heuristic, so listing them gives the user a chance to
      // spot a false positive.
      if (orph_dropped > 0) {
          lines.push_back(hbox({
              text("        dropped detail:") | dim,
          }));
          for (auto &dkv : dropped_by_module) {
              std::sort(dkv.second.begin(), dkv.second.end(), NaturalLess);
              std::string csv;
              for (size_t i = 0; i < dkv.second.size(); ++i) {
                  if (i) csv += ", ";
                  csv += dkv.second[i];
              }
              lines.push_back(hbox({
                  text("          " + dkv.first + ": ") | bold,
                  text(csv),
              }));
          }
      }
      lines.push_back(separator());
      lines.push_back(text("  Analysis") | bold);
      lines.push_back(hbox({text("  • ") | dim,
          text(std::to_string(n_diff)     + " diff pair(s)")}));
      lines.push_back(hbox({text("  • ") | dim,
          text(std::to_string(n_diff_bus) + " diff bus(es)")}));
      lines.push_back(hbox({text("  • ") | dim,
          text(std::to_string(n_bus)      + " bus(es)")}));
      lines.push_back(hbox({text("  • ") | dim,
          rep.anomalies.empty()
              ? text(std::to_string(rep.anomalies.size()) + " anomaly(ies)")
              : text(std::to_string(rep.anomalies.size()) + " anomaly(ies)")
                    | color(Color::Yellow)}));
      lines.push_back(separator());
      lines.push_back(text("  Modules") | bold);
      for (auto &r : mod_rows) lines.push_back(std::move(r));

      // Clamp scroll, mark a focused line so `yframe` positions the view.
      int line_count = (int)lines.size();
      if (dashboard_scroll_offset < 0) dashboard_scroll_offset = 0;
      if (dashboard_scroll_offset > line_count - 1)
          dashboard_scroll_offset = std::max(0, line_count - 1);
      lines[dashboard_scroll_offset] = lines[dashboard_scroll_offset] | focus;

      Element main_col = vbox(std::move(lines))
                       | vscroll_indicator
                       | yframe
                       | flex;

      Element help = RenderHelpPanel("dashboard", {
          {"c",      "console"},
          {"p",      "plug"},
          {"e",      "explore"},
          {"a",      "analyze (verify + groups)"},
          {"h",      "help screen"},
          {"x",      "export (CSV)"},
          {"PgUp",   "scroll up"},
          {"PgDn",   "scroll down"},
          {"Home",   "scroll top"},
          {"End",    "scroll bottom"},
          {"Ctrl-P", "palette"},
          {"q",      "quit"},
      });

      return vbox({
          title,
          separator(),
          hbox({main_col, separator(), help}) | flex,
      }) | border;
    });
}