import { Modal } from "./Modal";

export function HelpDialog({
  open,
  onClose,
}: {
  open: boolean;
  onClose: () => void;
}) {
  return (
    <Modal open={open} title="Sudoku Tools help" onClose={onClose} wide>
      <div className="help-grid">
        <section>
          <h3>Five complementary workspaces</h3>
          <p>
            <strong>Play</strong> keeps values, two kinds of notes, colours,
            branches, replay, guided hints and elapsed time.{" "}
            <strong>Set</strong> edits registry-backed clues and runs bounded
            setter-quality checks. <strong>Generate</strong> constructs and
            ranks bounded, seedable single or batch variants.{" "}
            <strong>Solve</strong> explains logical steps and can verify
            uniqueness. <strong>Helpers</strong> answers focused sum, candidate
            and relation questions without changing the board.
          </p>
        </section>
        <section>
          <h3>Keyboard</h3>
          <dl className="shortcut-list">
            <div>
              <dt>Arrow keys</dt>
              <dd>Move the active cell</dd>
            </div>
            <div>
              <dt>Shift + arrows</dt>
              <dd>Extend the selection</dd>
            </div>
            <div>
              <dt>Home / End</dt>
              <dd>Move to the first or last cell in the row</dd>
            </div>
            <div>
              <dt>Ctrl/⌘ + Home/End</dt>
              <dd>Move to the first or last cell in the grid</dd>
            </div>
            <div>
              <dt>Page Up / Down</dt>
              <dd>Move to the first or last row in the same column</dd>
            </div>
            <div>
              <dt>1–9 / A–G</dt>
              <dd>Enter the selected symbol</dd>
            </div>
            <div>
              <dt>Z / X / C / V</dt>
              <dd>Value, corner, centre or colour mode</dd>
            </div>
            <div>
              <dt>Backspace</dt>
              <dd>Erase in the current mode</dd>
            </div>
            <div>
              <dt>Ctrl/⌘ + Z/Y</dt>
              <dd>Undo or redo</dd>
            </div>
            <div>
              <dt>Ctrl/⌘ + click</dt>
              <dd>Highlight every placed copy of that digit</dd>
            </div>
            <div>
              <dt>M</dt>
              <dd>Toggle tap-by-tap multi-selection</dd>
            </div>
            <div>
              <dt>Ctrl/⌘ + + / −</dt>
              <dd>Zoom the board while focus is in the board area</dd>
            </div>
            <div>
              <dt>Ctrl/⌘ + 0</dt>
              <dd>Fit the board at its default scale</dd>
            </div>
          </dl>
        </section>
        <section>
          <h3>Touch, zoom and selection</h3>
          <p>
            Board zoom is stored in this browser. Use <strong>Pan board</strong>
            before dragging a zoomed board; its strong border and status message
            indicate that cell taps are temporarily paused. Stop panning to edit
            again. <strong>Tap multi-select</strong> toggles individual cells
            without a drag gesture and keeps one active cell for keyboard entry.
            On narrow screens the entry pad stays close to the bottom edge and
            respects the device safe area.
          </p>
        </section>
        <section>
          <h3>Hints and solutions</h3>
          <p>
            A guided hint reveals where to look, the technique, its reasoning
            and an effects preview in separate stages; the board changes only
            after <strong>Apply this step</strong>. Candidate legality is
            computed independently from handwritten notes. Controls can fill
            legal centre candidates, prune invalid centre/corner notes and
            optionally maintain peer notes after placements. Erasing a value
            never invents candidates.
          </p>
          <p>
            Logical deductions report premises, affected houses, placements and
            eliminations for singles, subsets, intersections, fish, wings,
            colouring, chains and Killer cages. Unique Rectangle is disabled
            unless a completed exact search has already proved uniqueness. Exact
            search is separately labelled and is not presented as a human
            explanation; reaching a limit remains unknown.
          </p>
        </section>
        <section>
          <h3>Setter-quality checks</h3>
          <p>
            Quick analysis checks for zero, one or two solutions and can show
            the cells where two completions differ. Full analysis uses bounded
            deletion searches to classify givens and constraints as critical,
            redundant or unknown, build a cell heatmap, or localise a
            contradictory core. Optional minimality is claimed only when the
            unique baseline and every required removal check complete. Per-check
            and aggregate budgets are visible, and analysis can be cancelled
            without turning a capped search into proof.
          </p>
        </section>
        <section>
          <h3>Branches, savepoints and replay</h3>
          <p>
            Open <strong>History &amp; branches</strong> while playing to name a
            checkpoint, isolate a hypothesis, or inspect an earlier grid.
            Discarding a hypothesis restores its exact starting state but keeps
            the abandoned path available in replay. Replayed grids are read-only
            until you return live or deliberately branch from that step.
            Validated history is included in local autosaves and explicit
            Library saves, so restoring that progress also restores its
            savepoints and branches.
          </p>
        </section>
        <section>
          <h3>Sum and Candidate Labs</h3>
          <p>
            Sum Lab enumerates bounded combinations and, when selected board
            cells are enabled, candidate-compatible assignments per position.
            Required, excluded and manually eliminated combinations remain local
            helper state. Candidate Lab inspects selected cells and houses,
            filters one or more digits, and can overlay strong and weak links
            without changing handwritten notes.
          </p>
        </section>
        <section>
          <h3>Aid-mémoire scratch cells</h3>
          <p>
            Enable the optional aid-mémoire in Play for a non-constraining row
            or compact grid of scratch cells. Each cell has its own label and
            accepts values, corner marks, centre marks and colours through the
            regular keypad or keyboard. Arrow keys stay within the configured
            grid; Home/End move within a row, Ctrl/⌘ + Home/End reach the first
            or last cell, and Page Up/Down move to the first or last row. The
            layout and entries are preserved with local Library progress.
          </p>
        </section>
        <section>
          <h3>Variant and false clues</h3>
          <p>
            The shared registry covers classic/irregular/extra regions;
            diagonal, anti, disjoint and non-consecutive rules; cages, parity,
            extrema and quadruples; thermo, arrow, renban, palindrome, between,
            whisper, region-sum, modular, entropic, zipper and double-arrow
            lines; Kropki, 5/10 and inequality pairs; X-sum, skyscraper,
            little-killer and sandwich clues; clone regions and row/column/box
            indexers.
          </p>
          <p>
            Enable Wrogn mode to make a supported local clue false, or switch
            existing clues individually or as a batch. Red dashed artwork and a
            ≠ mark identify false clues; global house rules, extra regions and
            fog are not given a misleading false mode. Fog is display-only and
            can be set only with a complete solution which validates against the
            current puzzle. Wrong entries reveal nothing and the trusted
            solution remains in the local puzzle document.
          </p>
        </section>
        <section>
          <h3>Generation and ratings</h3>
          <p>
            Generation runs in a worker with explicit time and search limits. It
            supports single or deterministic batch generation, compatible mixed
            families, sparse/balanced/dense local constraints and several
            rotational, reflection and diagonal clue symmetries. Minimal-givens
            mode reports proof or the exact unknown reason; individual
            minimisation can break the requested visual symmetry and reports
            that fact.
          </p>
          <p>
            Technique profiles can require, forbid or count techniques and set
            an exact hardest technique. A result is accepted only when an
            independent complete logical path matches the whole profile and an
            independent exact search proves uniqueness. Requested difficulty
            guides clue removal; the reported 0–100 rating is then calculated
            from logical techniques, clue load and exact-search evidence. A
            cancelled or bounded-out candidate remains a failure or unknown,
            never a uniqueness/minimality claim.
          </p>
        </section>
        <section>
          <h3>Import and privacy</h3>
          <p>
            Files, text, solving and generation stay in this browser. Compact
            grids, project JSON, share fragments, supported f-puzzles,
            SudokuPad/CTC inline data and supported Penpa+ long links are
            decoded locally. Server short IDs are intentionally rejected. The
            compatibility check separates mapped Sudoku semantics, preserved
            inert drawings, retained metadata and warnings before import. Source
            identity and allowlisted drawings survive local edits and saves but
            never become rules by appearance alone.
          </p>
          <p>
            Export includes Sudoku Tools JSON/share data, f-puzzles, SudokuPad
            JSON or self-contained SCL where representable, plus local SVG, PNG
            and PDF rendering. Unsupported false/global semantics and visual
            geometry are rejected rather than silently weakened. Review an
            export before sharing: titles, authors, rules, solutions, progress,
            source metadata, drawings and aid-mémoire entries may be included.
          </p>
        </section>
        <section>
          <h3>Recovery, Library and offline use</h3>
          <p>
            A separate debounced local autosave can restore or discard an
            interrupted session, including validated bounded history, branches
            and savepoints. Explicit Library projects offer title/tag search,
            completion filters, safe previews and selected export, duplication
            or deletion. Browser storage can be cleared independently, so export
            important projects.
          </p>
          <p>
            On a production HTTPS host, the first successful load can install a
            relative-scope offline application shell. Service-worker support is
            progressive enhancement: puzzle work stays local and remains usable
            when registration is unavailable.
          </p>
        </section>
        <section>
          <h3>Screen-reader detail</h3>
          <p>
            Each visible Sudoku cell reports its row, column, region, value,
            colour-and-pattern mark, conflict state and touching variant clues.
            Candidate detail can be set to <strong>Off</strong>, concise counts,
            or detailed digits without changing what is drawn. The board and
            aid-mémoire use real row and gridcell roles; their keyboard
            instructions are attached to the grids. Fogged cells report only
            that they are obscured: hidden values, notes, clues, candidate
            overlays and guided-hint steps are not exposed through board labels.
          </p>
        </section>
      </div>
    </Modal>
  );
}