Initial commit

README.md

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+# Knight's Daily Special Scraper
+Who doesn't love [Knight's](http://www.knightsrestaurants.com/)? Their steak sandwich lunch special is delicious. So here is a simple HTML scraper to get Knight's current lunch specials is a very interceptable way.
+
+## Installation
+
+### Requirements
+* Go version >= 1.5
+* GOPATH set in your ENV
+* (optional, but recommended) `$GOPATH/bin` in `$PATH`
+
+```bash
+go get -u github.com/tblyler/knights-special
+```
+
+## Documentation
+Run the following after installation...
+
+```bash
+knights-special --help
+```

main.go

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+package main
+
+import (
+	"encoding/json"
+	"flag"
+	"fmt"
+	"net/http"
+	"os"
+	"regexp"
+	"strconv"
+	"strings"
+
+	"golang.org/x/net/html"
+)
+
+const (
+	// the max font size used for format-pretty spaces
+	maxFontSize = 12
+
+	// the base url for knights
+	baseURL = "http://www.knightsrestaurants.com/specials/"
+)
+
+// regex to calculate format-pretty spaces per entry
+var fontRegex = regexp.MustCompile("FONT-SIZE:([0-9]+)pt")
+
+func main() {
+	jsonify := false
+	jsonPretty := false
+
+	lunch := false
+	dinner := false
+
+	downtown := false
+	annarbor := false
+	jackson := false
+
+	flag.BoolVar(&jsonify, "json", false, "output as JSON")
+	flag.BoolVar(&jsonPretty, "jsonPretty", false, "output as pretty JSON")
+	flag.BoolVar(&lunch, "lunch", false, "get the lunch special")
+	flag.BoolVar(&dinner, "dinner", false, "get the dinner special")
+	flag.BoolVar(&downtown, "downtown", false, "get the downtown special")
+	flag.BoolVar(&annarbor, "annarbor", false, "get the Ann Arbor Dexter Rd special")
+	flag.BoolVar(&jackson, "jackson", false, "get the Jackson special")
+	flag.Parse()
+
+	if jsonPretty {
+		jsonify = true
+	}
+
+	if (lunch && dinner) || (!lunch && !dinner) {
+		fmt.Fprintln(os.Stderr, "You must specify lunch or dinner, not multiples, nor neither")
+		flag.PrintDefaults()
+		os.Exit(1)
+	}
+
+	if (downtown && (annarbor || jackson)) || (annarbor && (downtown || jackson)) || (jackson && (annarbor || downtown)) {
+		fmt.Fprintln(os.Stderr, "You must specify only one location")
+		flag.PrintDefaults()
+		os.Exit(1)
+	}
+
+	url := baseURL
+	if annarbor {
+		if lunch {
+			url += "lunch_kbr.html"
+		} else if dinner {
+			url += "dinner_kbr.html"
+		} else {
+			fmt.Fprintln(os.Stderr, "Unable to determine the meal to pull from for Ann Arbor Dexter Rd")
+			flag.PrintDefaults()
+			os.Exit(1)
+		}
+	} else if downtown {
+		if lunch {
+			url += "lunch_klm.html"
+		} else if dinner {
+			url += "dinner_klm.html"
+		} else {
+			fmt.Fprintln(os.Stderr, "Unable to determine the meal to pull from for downtown")
+			flag.PrintDefaults()
+			os.Exit(1)
+		}
+	} else if jackson {
+		if lunch {
+			url += "lunch_krj.html"
+		} else if dinner {
+			url += "dinner_krj.html"
+		} else {
+			fmt.Fprintln(os.Stderr, "Unable to determine the meal to pull from for downtown")
+			flag.PrintDefaults()
+			os.Exit(1)
+		}
+	} else {
+		fmt.Fprintln(os.Stderr, "Unable to determine which location to pull from")
+		flag.PrintDefaults()
+		os.Exit(1)
+	}
+
+	// run as a callback for graceful error handling
+	err := func(url string, jsonify bool, jsonPretty bool) error {
+		// pull the raw HTML
+		resp, err := http.Get(url)
+		if err != nil {
+			return err
+		}
+
+		if resp.StatusCode != http.StatusOK {
+			return fmt.Errorf("Got bad status on request: %d", resp.StatusCode)
+		}
+
+		// start the HTML tokenizer to parse the HTML pulled from the website
+		tokenizer := html.NewTokenizer(resp.Body)
+		if tokenizer.Err() != nil {
+			return tokenizer.Err()
+		}
+
+		// this will store the output information
+		output := []string{}
+
+		// continue until /html
+		for tokenizer.Token().Data != "html" {
+			tokenType := tokenizer.Next()
+			if tokenType == html.StartTagToken {
+				token := tokenizer.Token()
+				if token.Data == "td" {
+					// keep track of the amount of spaces to prepend to the output string
+					spaces := 0
+
+					// go to the element that has text
+					for inner := tokenizer.Next(); inner != html.TextToken; inner = tokenizer.Next() {
+						if tokenizer.Err() != nil {
+							return tokenizer.Err()
+						}
+
+						if !jsonify {
+							// get the "font size" to determine the amount of spaces to use if this has a font attribute
+							for _, attr := range tokenizer.Token().Attr {
+								// use the predefined regex to check this attribute
+								fontSizeMatch := fontRegex.FindStringSubmatch(attr.Val)
+
+								// not a valid match, continue
+								if fontSizeMatch == nil {
+									continue
+								}
+
+								// trust the regex to not have a bad match for strcov.Atoi
+								fontSize, _ := strconv.Atoi(fontSizeMatch[1])
+
+								// assume that maxFontSize is correct
+								spaces = maxFontSize - fontSize
+								break
+							}
+						}
+					}
+
+					if !jsonify {
+						// if this is the first entry, have no spaces regardless of the font value
+						if len(output) == 0 {
+							spaces = 0
+						}
+					}
+
+					// prepend the amount of spaces to the output text and add it to the output slice
+					output = append(output, strings.Repeat(" ", spaces)+strings.TrimSpace(string(tokenizer.Text())))
+				}
+			}
+		}
+
+		if jsonify {
+			jsonOutput := ""
+			if jsonPretty {
+				jsonByte, err := json.MarshalIndent(output, "", "  ")
+				if err != nil {
+					return err
+				}
+
+				jsonOutput = string(jsonByte)
+			} else {
+				jsonByte, err := json.Marshal(output)
+				if err != nil {
+					return err
+				}
+
+				jsonOutput = string(jsonByte)
+			}
+
+			fmt.Println(jsonOutput)
+		} else {
+			for _, line := range output {
+				fmt.Println(line)
+			}
+		}
+
+		return nil
+	}(url, jsonify, jsonPretty)
+
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+}