// Generates the ASCII hex map by painting province polygons, prints preview.
const W = 27, H = 29;
const grid = Array.from({ length: H }, () => Array(W).fill("."));

// point in polygon (hex-center space, col/row floats)
function pip(x, y, poly) {
  let inside = false;
  for (let i = 0, j = poly.length - 1; i < poly.length; j = i++) {
    const [xi, yi] = poly[i], [xj, yj] = poly[j];
    if ((yi > y) !== (yj > y) && x < ((xj - xi) * (y - yi)) / (yj - yi) + xi) inside = !inside;
  }
  return inside;
}

// painted in order; later paints overwrite
const PAINTS = [
  ["g", [[1,10],[8,9],[10,12],[10,15],[9,18],[8,22],[6,26],[3,26],[1,20],[0,14]]],
  ["n", [[6,11],[14,11],[16,13],[16,17],[14,21],[11,22],[8,20],[6,16]]],
  ["h", [[15,11],[21,11],[25,14],[24,19],[19,21],[15,18],[15,13]]],
  ["u", [[11,10],[17,10],[18,13],[16,16],[12,16],[10,13]]],
  ["x", [[15,9],[21,9],[22,12],[19,15],[16,14],[15,11]]],
  ["l", [[0,0],[8,0],[8,4],[6,6],[3,7],[0,6]]],
  ["o", [[4,4],[10,4],[11,7],[10,10],[7,11],[5,9],[3,7]]],
  ["s", [[7,7],[12,7],[13,10],[11,12],[8,12],[6,9]]],
  ["y", [[9,1],[17,1],[18,4],[16,6],[11,6],[9,4]]],
  ["j", [[9,4],[17,5],[17,8],[13,9],[10,7],[9,5]]],
  ["q", [[15,6],[22,6],[23,9],[20,12],[17,11],[15,9]]],
  ["a", [[11,8],[16,8],[17,11],[15,13],[11,13],[10,10]]],
];

for (const [ch, poly] of PAINTS)
  for (let r = 0; r < H; r++)
    for (let c = 0; c < W; c++)
      if (pip(c, r, poly)) grid[r][c] = ch;

// mountain ranges (uppercase) — hand bands
function band(pts, chs) {
  // mark cells near polyline
  for (let r = 0; r < H; r++) for (let c = 0; c < W; c++) {
    if (grid[r][c] === ".") continue;
    let d = 1e9;
    for (let i = 0; i < pts.length - 1; i++) {
      const [x1, y1] = pts[i], [x2, y2] = pts[i + 1];
      const dx = x2 - x1, dy = y2 - y1;
      const t = Math.max(0, Math.min(1, ((c - x1) * dx + (r - y1) * dy) / (dx * dx + dy * dy)));
      d = Math.min(d, Math.hypot(c - (x1 + t * dx), r - (y1 + t * dy)));
    }
    if (d < 0.75 && chs.includes(grid[r][c])) grid[r][c] = grid[r][c].toUpperCase();
  }
}
band([[9,4],[11,5],[11,7]], ["j","o"]);          // Taihang
band([[6,9],[9,10],[11,11]], ["o","s","g"]);     // Qinling west
band([[11,12],[13,12],[15,13]], ["s","u","n"]);  // Funiu
band([[2,12],[4,13],[6,15]], ["g"]);             // Daba/Shu west
band([[7,17],[8,20],[7,23]], ["g","n"]);         // southern highlands
band([[1,1],[3,3],[5,5]], ["l"]);                // Hexi mountains
band([[16,1],[17,3],[16,5]], ["y"]);             // Yan mountains
band([[19,6],[21,8]], ["q"]);                    // Shandong hills

console.log(grid.map((row, r) => String(r).padStart(2) + " " + row.join("")).join("\n"));

// ---------- bake ----------
const CITIES = [
  ["ji","y",12,2],["beiping","y",15,2],
  ["ye","j",12,6],["nanpi","j",15,5],
  ["linzi","q",17,7],["beihai","q",21,8],
  ["puyang","a",12,9],["chenliu","a",14,10],
  ["luoyang","s",9,9],["hongnong","s",8,11],
  ["changan","o",7,8],["anding","o",5,6],
  ["wuwei","l",2,3],["tianshui","l",4,5],
  ["xiaopei","x",16,12],["xiapi","x",19,13],
  ["xuchang","u",14,12],["wan","u",12,14],["runan","u",15,14],
  ["shouchun","h",18,15],["jianye","h",21,14],["lujiang","h",18,17],["wu","h",21,17],
  ["xiangyang","n",10,14],["jiangling","n",11,17],["jiangxia","n",14,15],["changsha","n",11,20],
  ["hanzhong","g",4,11],["chengdu","g",3,15],["zitong","g",3,13],["jiangzhou","g",6,17],["yunnan","g",6,22],
];
function snap(prov, c, r) {
  let best = null, bd = 1e9;
  for (let rr = 0; rr < H; rr++) for (let cc = 0; cc < W; cc++) {
    if (grid[rr][cc].toLowerCase() !== prov) continue;
    const d = Math.hypot(cc - c, rr - r);
    if (d < bd) { bd = d; best = [cc, rr]; }
  }
  return best;
}
console.log("\n=== CITY COORDS ===");
const used = new Set();
for (const [id, p, c, r] of CITIES) {
  const [cc, rr] = snap(p, c, r);
  if (!cc && cc !== 0) { console.log(`!! ${id} NO TILE for ${p}`); continue; }
  if (used.has(cc+","+rr)) console.log(`!! overlap ${id} @${cc},${rr}`);
  used.add(cc+","+rr);
  console.log(`["${id}", "${cc}", "${rr}"],`);
}
const RIVERS = [
  ["Yellow River", [[5,6],[6,7],[7,8],[8,8],[9,9],[10,9],[11,8],[12,7],[13,7],[14,8],[16,8],[18,8],[20,8]]],
  ["Yangtze", [[3,15],[4,15],[6,15],[8,15],[10,15],[12,15],[13,15],[15,15],[17,16],[19,16],[21,16],[23,17]]],
  ["Han", [[9,12],[9,13],[10,14]]],
  ["Huai", [[14,13],[16,13],[18,14],[19,15]]],
];
console.log("\n=== RIVERS ===");
for (const [name, pts] of RIVERS) {
  const out = pts.map(([c, r]) => {
    // nearest land tile
    let best = null, bd = 1e9;
    for (let rr = 0; rr < H; rr++) for (let cc = 0; cc < W; cc++) {
      if (grid[rr][cc] === ".") continue;
      const d = Math.hypot(cc - c, rr - r);
      if (d < bd) { bd = d; best = [cc, rr]; }
    }
    return best;
  });
  console.log(`{ name: "${name}", pts: [${out.map(([c,r])=>`[${c},${r}]`).join(",")}] },`);
}
console.log("\n=== MAP_ROWS ===");
console.log("export const MAP_ROWS = [");
for (const row of grid) console.log(`  "${row.join("")}",`);
console.log("];");