Add all the functionality

.gitignore

@@ -13,3 +13,6 @@
 
 # Dependency directories (remove the comment below to include it)
 # vendor/
+
+# Visual Studio Code
+.vscode

cmd/cmd.go

@@ -0,0 +1,182 @@
+package cmd
+
+import (
+	"encoding/json"
+	"flag"
+	"fmt"
+	"log"
+	"os"
+	"strconv"
+	"text/template"
+
+	"github.com/PuerkitoBio/goquery"
+	"github.com/midir99/rastreadora/mpp"
+	"github.com/midir99/rastreadora/ws"
+)
+
+type Scraper string
+
+const (
+	ScraperGroAlba   = "gro-alba"
+	ScraperGroAmber  = "gro-amber"
+	ScraperMorAmber  = "mor-amber"
+	ScraperMorCustom = "mor-custom"
+)
+
+func ScrapersAvailable() []Scraper {
+	return []Scraper{
+		ScraperGroAlba,
+		ScraperGroAmber,
+		ScraperMorAmber,
+		ScraperMorCustom,
+	}
+}
+
+var usageTemplate = `rastreadora is a tool for scraping missing person posters data.
+
+Usage:
+
+    rastreadora [-o output] <scraper> <from> [until]
+
+Arguments:
+
+    scraper (string): the scraper that will be used to extract data, available values:{{range .Scrapers}}
+                      - {{.}}{{end}}
+    from    (number): the page number to start scraping missing person posters data.
+    until   (number): the page number to stop scraping missing person posters data, if omitted
+                      the program will only scrap data from the page number specified by the
+                      <from> argument.
+
+Flags:
+
+    -o      (string): the filename where the data will be stored, if omitted the data will be
+                      dumped in STDOUT.
+    -V      (bool):   print the version of the program.
+    -h      (bool):   print this usage message.
+`
+
+func Usage() {
+	templateData := struct {
+		Scrapers []Scraper
+	}{Scrapers: ScrapersAvailable()}
+	tmpl := template.Must(template.New("usage").Parse(usageTemplate))
+	err := tmpl.Execute(flag.CommandLine.Output(), templateData)
+	if err != nil {
+		fmt.Fprint(flag.CommandLine.Output(), "unable to print help")
+	}
+}
+
+type Args struct {
+	Scraper      Scraper
+	PageFrom     uint64
+	PageUntil    uint64
+	Out          string
+	PrintVersion bool
+}
+
+func ParseArgs() (*Args, error) {
+	args := Args{}
+	flag.StringVar(&args.Out, "o", "", "the filename to dump the missing-person posters data, if not present data is dumped into stdout")
+	flag.BoolVar(&args.PrintVersion, "V", false, "print the version of the program")
+	flag.Usage = Usage
+	flag.Parse()
+	if args.PrintVersion {
+		return &args, nil
+	}
+	// Validate the "scraper" argument
+	args.Scraper = Scraper(flag.Arg(0))
+	if args.Scraper == "" {
+		return nil, fmt.Errorf("<scraper> argument cannot be empty")
+	}
+	scraperIsValid := false
+	for _, s := range ScrapersAvailable() {
+		if args.Scraper == s {
+			scraperIsValid = true
+			break
+		}
+	}
+	if !scraperIsValid {
+		return nil, fmt.Errorf("\"%s\" is not a valid choice for <scraper>", args.Scraper)
+	}
+	// Validate the "from" argument
+	if flag.Arg(1) == "" {
+		return nil, fmt.Errorf("<from> argument cannot be empty")
+	}
+	pF, err := strconv.ParseUint(flag.Arg(1), 10, 0)
+	if err != nil {
+		return nil, fmt.Errorf("\"%s\" is not a valid number for <from>", flag.Arg(1))
+	}
+	args.PageFrom = pF
+	// Validate the "until" argument
+	if flag.Arg(2) == "" {
+		args.PageUntil = args.PageFrom
+	} else {
+		pU, err := strconv.ParseUint(flag.Arg(2), 10, 0)
+		if err != nil {
+			return nil, fmt.Errorf("\"%s\" is not a valid number for [until]", flag.Arg(2))
+		}
+		args.PageUntil = pU
+	}
+	// Validate "from" value is lower or equal to "until" value
+	if args.PageFrom > args.PageUntil {
+		return nil, fmt.Errorf("<from> value must be lower or equal to [until] value")
+	}
+	return &args, nil
+}
+
+func PrintVersion() {
+	fmt.Println("rastreadora v0.0.1")
+}
+
+func SelectScraperFuncs(scraper Scraper) (func(*goquery.Document) []mpp.MissingPersonPoster, func(uint64) string, error) {
+	switch scraper {
+	case ScraperGroAlba:
+		return ws.ScrapeGroAlbaAlerts, ws.MakeGroAlbaUrl, nil
+	case ScraperGroAmber:
+		return ws.ScrapeGroAmberAlerts, ws.MakeGroAmberUrl, nil
+	case ScraperMorAmber:
+		return ws.ScrapeMorAmberAlerts, ws.MakeMorAmberUrl, nil
+	case ScraperMorCustom:
+		return ws.ScrapeMorCustomAlerts, ws.MakeMorCustomUrl, nil
+	default:
+		return nil, nil, fmt.Errorf("invalid scraper %v", scraper)
+	}
+}
+
+func Execute(args *Args) {
+	if args.PrintVersion {
+		PrintVersion()
+		os.Exit(0)
+	}
+	scraper, makeUrl, err := SelectScraperFuncs(args.Scraper)
+	if err != nil {
+		log.Fatalf("Error: %s", err)
+	}
+	ch := make(chan []mpp.MissingPersonPoster)
+	for pageNum := args.PageFrom; pageNum <= args.PageUntil; pageNum++ {
+		pageUrl := makeUrl(pageNum)
+		log.Printf("Processing %s ...\n", pageUrl)
+		go ws.Scrape(pageUrl, scraper, ch)
+	}
+	mpps := []mpp.MissingPersonPoster{}
+	pagesCount := args.PageUntil - args.PageFrom + 1
+	for curPage := uint64(1); curPage <= pagesCount; curPage++ {
+		mpps = append(mpps, <-ch...)
+		log.Printf("%d out of %d page(s) have been scraped\n", curPage, pagesCount)
+	}
+	output, err := json.Marshal(mpps)
+	if err != nil {
+		log.Fatal("Error: ", err)
+	}
+	if args.Out != "" {
+		if os.WriteFile(args.Out, output, 0664) != nil {
+			log.Fatalf("Error: %s", err)
+		}
+	} else {
+		_, err := os.Stdout.Write(output)
+		if err != nil {
+			log.Fatalf("Error: %s", err)
+		}
+	}
+	log.Printf("%d missing person poster(s) were processed\n", len(mpps))
+}

go.mod

@@ -0,0 +1,9 @@
+module github.com/midir99/rastreadora
+
+go 1.18
+
+require (
+	github.com/PuerkitoBio/goquery v1.8.0
+	github.com/andybalholm/cascadia v1.3.1 // indirect
+	golang.org/x/net v0.0.0-20210916014120-12bc252f5db8 // indirect
+)

go.sum

@@ -0,0 +1,11 @@
+github.com/PuerkitoBio/goquery v1.8.0 h1:PJTF7AmFCFKk1N6V6jmKfrNH9tV5pNE6lZMkG0gta/U=
+github.com/PuerkitoBio/goquery v1.8.0/go.mod h1:ypIiRMtY7COPGk+I/YbZLbxsxn9g5ejnI2HSMtkjZvI=
+github.com/andybalholm/cascadia v1.3.1 h1:nhxRkql1kdYCc8Snf7D5/D3spOX+dBgjA6u8x004T2c=
+github.com/andybalholm/cascadia v1.3.1/go.mod h1:R4bJ1UQfqADjvDa4P6HZHLh/3OxWWEqc0Sk8XGwHqvA=
+golang.org/x/net v0.0.0-20210916014120-12bc252f5db8 h1:/6y1LfuqNuQdHAm0jjtPtgRcxIxjVZgm5OTu8/QhZvk=
+golang.org/x/net v0.0.0-20210916014120-12bc252f5db8/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
+golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
+golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=

main.go

@@ -0,0 +1,23 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+
+	"github.com/midir99/rastreadora/cmd"
+)
+
+func main() {
+	args, err := cmd.ParseArgs()
+	if err != nil {
+		fmt.Fprint(
+			flag.CommandLine.Output(),
+			"Error: ",
+			err,
+			"\nTry using the -h flag to get some help.\n",
+		)
+		os.Exit(1)
+	}
+	cmd.Execute(args)
+}

mpp/mpp.go

@@ -0,0 +1,98 @@
+package mpp
+
+type State string
+
+const (
+	StateCiudadDeMexico             State = "MX-CMX"
+	StateAguascalientes             State = "MX-AGU"
+	StateBajaCalifornia             State = "MX-BCN"
+	StateBajaCaliforniaSur          State = "MX-BCS"
+	StateCampeche                   State = "MX-CAM"
+	StateCoahuilaDeZaragoza         State = "MX-COA"
+	StateColima                     State = "MX-COL"
+	StateChiapas                    State = "MX-CHP"
+	StateChihuahua                  State = "MX-CHH"
+	StateDurango                    State = "MX-DUR"
+	StateGuanajuato                 State = "MX-GUA"
+	StateGuerrero                   State = "MX-GRO"
+	StateHidalgo                    State = "MX-HID"
+	StateJalisco                    State = "MX-JAL"
+	StateMexico                     State = "MX-MEX"
+	StateMichoacanDeOcampo          State = "MX-MIC"
+	StateMorelos                    State = "MX-MOR"
+	StateNayarit                    State = "MX-NAY"
+	StateNuevoLeon                  State = "MX-NLE"
+	StateOaxaca                     State = "MX-OAX"
+	StatePuebla                     State = "MX-PUE"
+	StateQueretaro                  State = "MX-QUE"
+	StateQuintanaRoo                State = "MX-ROO"
+	StateSanLuisPotosi              State = "MX-SLP"
+	StateSinaloa                    State = "MX-SIN"
+	StateSonora                     State = "MX-SON"
+	StateTabasco                    State = "MX-TAB"
+	StateTamaulipas                 State = "MX-TAM"
+	StateTlaxcala                   State = "MX-TLA"
+	StateVeracruzDeIgnacioDeLaLlave State = "MX-VER"
+	StateYucatan                    State = "MX-YUC"
+	StateZacatecas                  State = "MX-ZAC"
+)
+
+type PhysicalBuild string
+
+const (
+	PhysicalBuildSlim    PhysicalBuild = "S"
+	PhysicalBuildRegular PhysicalBuild = "R"
+	PhysicalBuildHeavy   PhysicalBuild = "H"
+)
+
+type Complexion string
+
+const (
+	ComplexionVeryLight         Complexion = "VL"
+	ComplexionLight             Complexion = "L"
+	ComplexionLightIntermediate Complexion = "LI"
+	ComplexionDarkIntermediate  Complexion = "DI"
+	ComplexionDark              Complexion = "D"
+	ComplexionVeryDark          Complexion = "VD"
+)
+
+type Sex string
+
+const (
+	SexFemale Sex = "F"
+	SexMale   Sex = "M"
+)
+
+type AlertType string
+
+const (
+	AlertTypeAlba      AlertType = "AL"
+	AlertTypeAmber     AlertType = "AM"
+	AlertTypeHasVistoA AlertType = "HV"
+	AlertTypeOdisea    AlertType = "OD"
+)
+
+type MissingPersonPoster struct {
+	MpName                           string        `json:"mp_name"`
+	MpHeight                         uint          `json:"mp_height,omitempty"`
+	MpWeight                         uint          `json:"mp_weight,omitempty"`
+	MpPhysicalBuild                  PhysicalBuild `json:"mp_physical_build,omitempty"`
+	MpComplexion                     Complexion    `json:"mp_complexion,omitempty"`
+	MpSex                            Sex           `json:"mp_sex,omitempty"`
+	MpDob                            string        `json:"mp_dob,omitempty"`
+	MpAgeWhenDisappeared             uint          `json:"mp_age_when_disappeared,omitempty"`
+	MpEyesDescription                string        `json:"mp_eyes_description,omitempty"`
+	MpHairDescription                string        `json:"mp_hair_description,omitempty"`
+	MpOutfitDescription              string        `json:"mp_outfit_description,omitempty"`
+	MpIdentifyingCharacteristics     string        `json:"mp_identifying_characteristics,omitempty"`
+	CircumstancesBehindDissapearance string        `json:"circumstances_behind_dissapearance,omitempty"`
+	MissingFrom                      string        `json:"missing_from,omitempty"`
+	MissingDate                      string        `json:"missing_date,omitempty"`
+	Found                            bool          `json:"found,omitempty"`
+	AlertType                        AlertType     `json:"alert_type,omitempty"`
+	PoState                          State         `json:"po_state"`
+	PoPostUrl                        string        `json:"po_post_url,omitempty"`
+	PoPostPublicationDate            string        `json:"po_post_publication_date,omitempty"`
+	PoPosterUrl                      string        `json:"po_poster_url,omitempty"`
+	IsMultiple                       bool          `json:"is_multiple,omitempty"`
+}