func getClues(n *html.Node) (uint8, uint8, error) {
if c := htmlutil.GetElChildren(n, "table"); len(c) == 0 {
return 0, 0, gridErr("table not found")
} else {
n = c[0]
}
if cl, _ := htmlutil.GetAttr(n, "class"); cl != "infotablegrey" {
return 0, 0, gridErr("Wrong table class")
}
tab, err := htmlutil.ParseTable(n)
if err != nil {
return 0, 0, err
}
if len(tab) != 2 || len(tab[0]) != 2 || len(tab[1]) != 2 {
return 0, 0, gridErr("Wrong table size")
}
v, err := getClue(tab[1][0])
if err != nil {
return 0, 0, err
}
h, err := getClue(tab[0][1])
if err != nil {
return 0, 0, nil
}
return v, h, nil
}
func parseHTMLCell(n *html.Node) (Cell, error) {
switch v, _ := htmlutil.GetAttr(n, "class"); v {
case "whitegrey":
return &ValueCell{Val: bitset.Interval(1, 9)}, nil
case "grey":
return &ClueCell{}, nil
case "infocellgrey":
if v, h, err := getClues(n); err != nil {
return nil, err
} else {
return &ClueCell{VClue: v, HClue: h}, nil
}
default:
return nil, gridErr("Unknown or missing cell class")
}
}
func FetchGrid(url string) (*Grid, error) {
resp, err := http.Get(url)
if err != nil {
return nil, err
}
defer resp.Body.Close()
n, err := html.Parse(resp.Body)
if err != nil {
return nil, err
}
for _, tag := range []string{"html", "body", "table"} {
if c := htmlutil.GetElChildren(n, tag); len(c) == 0 {
return nil, gridErr(tag + " not found")
} else {
n = c[0]
}
}
if cl, _ := htmlutil.GetAttr(n, "class"); cl != "kakurotablegrey" {
return nil, gridErr("Wrong table class")
}
tab, err := htmlutil.ParseTable(n)
if len(tab) < 2 {
return nil, gridErr("Grid too short")
}
colCount := len(tab[0])
if colCount < 2 {
return nil, gridErr("Grid too narrow")
}
for _, r := range tab {
if len(r) != colCount {
return nil, gridErr("Rows of different lengths")
}
}
g := &Grid{h: len(tab), w: colCount, cells: make([][]Cell, len(tab))}
for i, r := range tab {
g.cells[i] = make([]Cell, g.w)
for j, c := range r {
if x, err := parseHTMLCell(c); err != nil {
return nil, err
} else {
g.cells[i][j] = x
}
}
}
return g, nil
}