import type { Theme } from "@earendil-works/pi-coding-agent";
import { truncateToWidth } from "@earendil-works/pi-tui";
import { MOTION_CATALOG } from "../../../motion/catalog.ts";
import { appearanceDisplayName } from "../../../config/structural-presets.ts";
import { PRESETS } from "../../../config/presets.ts";
import { config } from "../../core/state.ts";
import type { PowerlineShortcuts } from "../../core/types.ts";
import type { ComposerDraft } from "../../../motion/composer.ts";
import { DECK_ROUTE_DEFS } from "./routes.ts";
import type { DeckNavState, DeckRoute, DeckSessionSnapshot } from "./types.ts";
import {
  appearanceLines,
  guardrailLines,
  ideasLines,
  motionGalleryLines,
  skillsWorkbenchLines,
} from "./route-bodies.ts";

function bar(percent: number, width: number): string {
  const filled = Math.round((Math.max(0, Math.min(100, percent)) / 100) * width);
  return `${"█".repeat(filled)}${"░".repeat(Math.max(0, width - filled))}`;
}

function routeTitle(route: DeckRoute): string {
  return DECK_ROUTE_DEFS.find((entry) => entry.id === route)?.label ?? "Home";
}

export function deckFooter(state: DeckNavState): string {
  if (state.searchOpen) return `/ ${state.searchQuery}_`;
  if (state.composerOpen) return "←→ nudge · ↑↓ field · enter apply · esc back";
  if (state.skillCreate) return "type a name · enter create · esc cancel";
  // Nav column has focus: ↑↓ walks routes, → jumps back into the list.
  if (state.navMode)
    return "↑↓ route · → list · / Search · g h Home · Esc Close";
  switch (state.route) {
    case "appearance":
      return "↑↓ select base · enter apply · ←/tab nav · → list · / Search · g h Home · Esc Close";
    case "motion":
      return "↑↓ motion · t event · e composer · enter apply · ←/tab nav · → list · Esc Close";
    case "skills":
      return "↑↓ skill · enter insert · n new · / filter · ←/tab nav · → list · Esc Close";
    case "ideas":
      return "↑↓ idea · / Search · ←/tab nav · → list · g h Home · Esc Close";
    default:
      return "/ Search   g h Home   g s Signal   g i Ideas   ? Help   Esc Close";
  }
}

export function renderDeckFrame(
  theme: Theme,
  width: number,
  snapshot: DeckSessionSnapshot,
  state: DeckNavState,
  shortcuts: PowerlineShortcuts,
  composer: ComposerDraft | null = null,
  tick = Date.now(),
): string[] {
  const inner = Math.max(40, width - 2);
  const border = (text: string) => theme.fg("dim", text);
  const wrap = (text: string) =>
    `${border("│")}${truncateToWidth(text, inner, "…", true)}${border("│")}`;

  const leftW = Math.max(14, Math.floor(inner * 0.18));
  const rightW = Math.max(18, Math.floor(inner * 0.24));
  const centerW = Math.max(20, inner - leftW - rightW - 4);

  const header = ` ◈ ${snapshot.modelLabel}   ${snapshot.branchLabel}   context ${snapshot.contextPercent}%   ${snapshot.signalActivity.toUpperCase()} `;
  const lines: string[] = [];
  lines.push(border(`╭${"─".repeat(inner)}╮`));
  lines.push(wrap(theme.fg("accent", theme.bold(truncateToWidth(header, inner, "…", true)))));
  lines.push(border(`├${"─".repeat(inner)}┤`));

  const nav = navLines(snapshot, state, theme, leftW, state.navMode);
  const center = centerRouteBody(snapshot, state, theme, centerW, shortcuts, composer, tick);
  const right = rightRail(snapshot, theme, rightW);

  const rowCount = Math.max(nav.length, center.length, right.length, 8);
  for (let i = 0; i < rowCount; i++) {
    const left = padCol(nav[i] ?? "", leftW);
    const mid = padCol(center[i] ?? "", centerW);
    const rightCol = padCol(right[i] ?? "", rightW);
    lines.push(wrap(`${left} ${mid} ${rightCol}`));
  }

  lines.push(border(`├${"─".repeat(inner)}┤`));
  const footer = deckFooter(state);
  lines.push(wrap(theme.fg("dim", truncateToWidth(footer, inner, "…", true))));
  lines.push(border(`╰${"─".repeat(inner)}╯`));
  return lines;
}

function navLines(
  snapshot: DeckSessionSnapshot,
  state: DeckNavState,
  theme: Theme,
  width: number,
  focused: boolean,
): string[] {
  // Focus marker: ◉ = ↑↓ walks this column, ○ = ↑↓ moves the center list.
  // Without this the cursor appears to "go right" on ↓ while list-focused.
  const header = focused
    ? theme.fg("accent", theme.bold("◉ NAVIGATION"))
    : theme.fg("muted", "○ NAVIGATION");
  const lines: string[] = [header];
  for (const route of DECK_ROUTE_DEFS) {
    const active = route.id === state.route;
    const marker = active ? "◉" : "◇";
    let suffix = "";
    if (route.id === "skills") suffix = ` ${snapshot.skillsTotal}`;
    if (route.id === "ideas") suffix = ` ${snapshot.ideaCount}`;
    lines.push(
      theme.fg(
        active ? "accent" : "muted",
        truncateToWidth(`${marker} ${route.label}${suffix}`, width, "…", true),
      ),
    );
  }
  return lines;
}

function centerRouteBody(
  snapshot: DeckSessionSnapshot,
  state: DeckNavState,
  theme: Theme,
  width: number,
  shortcuts: PowerlineShortcuts,
  composer: ComposerDraft | null = null,
  tick = Date.now(),
): string[] {
  const listFocused =
    !state.navMode && !state.searchOpen && !state.composerOpen;
  const title = listFocused
    ? theme.fg(
        "accent",
        theme.bold(`◉ ACTIVE ROUTE: ${routeTitle(state.route).toUpperCase()}`),
      )
    : theme.fg(
        "muted",
        `○ ACTIVE ROUTE: ${routeTitle(state.route).toUpperCase()}`,
      );
  const body: string[] = [title, ""];
  switch (state.route) {
    case "home":
      body.push(theme.fg("text", "CURRENT SESSION"));
      body.push(
        theme.fg(
          "accent",
          truncateToWidth(`◆ ${snapshot.signalActivity}`, width, "…", true),
        ),
      );
      body.push(
        truncateToWidth(
          `${bar(snapshot.contextPercent, Math.min(18, width - 12))} ${snapshot.contextPercent}% (${formatK(snapshot.contextTokens)} / ${formatK(snapshot.contextWindow)})`,
          width,
          "…",
          true,
        ),
      );
      body.push(
        truncateToWidth(
          `${appearanceDisplayName(snapshot.appearanceBase)} · ${snapshot.signalMotion} · ${snapshot.motionLevel}`,
          width,
          "…",
          true,
        ),
      );
      body.push("");
      body.push(theme.fg("text", "NEXT INTENT"));
      body.push(
        truncateToWidth(snapshot.nextIntent ?? "No queued intent", width, "…", true),
      );
      break;
    case "signal":
      body.push("THREE LANES");
      body.push("Identity · Activity · Context");
      body.push(`Layout ${config.preset} · placement ${config.placement}`);
      body.push(
        `Base ${appearanceDisplayName(snapshot.appearanceBase)} · motion ${snapshot.signalMotion}`,
      );
      body.push(`Level ${snapshot.motionLevel} · activity ${snapshot.signalActivity}`);
      body.push("Use /signal preset · placement · doctor");
      break;
    case "skills":
      body.push(...skillsWorkbenchLines(snapshot, state, width));
      break;
    case "ideas":
      body.push(...ideasLines(snapshot, state));
      break;
    case "guardrails":
      body.push(...guardrailLines(snapshot));
      break;
    case "shell":
      body.push(`Bash mode: ${snapshot.bashModeActive ? "on" : "off"}`);
      body.push(`Shell: ${snapshot.shellName ?? "not started"}`);
      body.push("Toggle with /bash-mode");
      break;
    case "usage":
      body.push(
        `Context ${snapshot.contextPercent}% · ${formatK(snapshot.contextTokens)} tokens`,
      );
      body.push("Open /usage for detailed overlay");
      break;
    case "appearance":
      body.push(...appearanceLines(snapshot, state));
      break;
    case "motion":
      body.push(...motionGalleryLines(snapshot, state, width, composer, tick));
      break;
    case "shortcuts":
      body.push(`Menu: ${shortcuts.menu ?? "alt+p"}`);
      body.push(`Queue: ${shortcuts.queueOpen ?? "ctrl+alt+q"}`);
      body.push(`Info: ${shortcuts.info ?? "alt+i"}`);
      body.push("g <key> jumps inside the Deck");
      break;
    case "diagnostics":
      body.push("Run /signal doctor for the full environment report");
      body.push(snapshot.policySummary);
      body.push(`Preset: ${config.preset} · base ${snapshot.appearanceBase}`);
      body.push(`Catalog: ${MOTION_CATALOG.length} motions`);
      break;
  }
  return body.map((line) => truncateToWidth(line, width, "…", true));
}

function rightRail(snapshot: DeckSessionSnapshot, theme: Theme, width: number): string[] {
  const lines = [theme.fg("accent", "ACTIVITY FEED"), ""];
  if (snapshot.recentActivity.length === 0) {
    lines.push(theme.fg("muted", "No recent activity"));
  } else {
    for (const item of snapshot.recentActivity) {
      lines.push(truncateToWidth(`· ${item}`, width, "…", true));
    }
  }
  lines.push("");
  lines.push(theme.fg("accent", "SKILLS HEALTH"));
  lines.push(`✓ ${snapshot.skillsTotal - snapshot.skillsWarnings} healthy`);
  if (snapshot.skillsWarnings > 0) {
    lines.push(theme.fg("warning", `! ${snapshot.skillsWarnings} warnings`));
  }
  lines.push("");
  lines.push(theme.fg("accent", "GUARDRAILS"));
  lines.push(
    truncateToWidth(
      `Policy: ${snapshot.policyEnabled ? "ON" : "OFF"} (${snapshot.policyRuleCount})`,
      width,
      "…",
      true,
    ),
  );
  return lines;
}

function padCol(text: string, width: number): string {
  const plain = stripAnsi(text);
  if (plain.length >= width) return truncateToWidth(text, width, "…", true);
  return text + " ".repeat(width - plain.length);
}

function stripAnsi(text: string): string {
  return text.replace(/\x1b\[[0-9;]*m/g, "");
}

function formatK(value: number): string {
  if (value >= 1000) return `${Math.round(value / 1000)}k`;
  return String(value);
}

export function filterDeckRoutes(query: string): DeckRoute[] {
  const q = query.trim().toLowerCase();
  if (!q) return DECK_ROUTE_DEFS.map((route) => route.id);
  return DECK_ROUTE_DEFS.filter((route) => {
    const hay = `${route.label} ${route.id} ${route.description}`.toLowerCase();
    return hay.includes(q);
  }).map((route) => route.id);
}

export function layoutPresetNames(): string[] {
  return Object.keys(PRESETS);
}