Solved - Degree of Separation (See Description for run command)

main.go

@@ -0,0 +1,326 @@
+package main
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"os"
+	"sync"
+	"time"
+)
+
+type movieMember interface {
+	GetName() string
+	GetURL() string
+	GetRole() string
+}
+
+type movieMemberWrapper struct {
+	Members []movieMember
+}
+
+func (m movieMemberWrapper) GetURL() string {
+	if len(m.Members) > 0 {
+		return m.Members[0].GetURL()
+	}
+	return ""
+}
+
+func (m movieMemberWrapper) AddMembers(members ...movieMember) {
+	m.Members = append(m.Members, members...)
+}
+
+type dos struct {
+	Movie          string
+	Person1, Role1 string
+	Person2, Role2 string
+}
+
+type personInfo struct {
+	Name   string
+	URL    string
+	Movies []movie
+	Cast   []cast
+	Crew   []crew
+}
+
+type movie struct {
+	Name string `json:"name"`
+	URL  string `json:"url"`
+	Type string `json:"type"`
+	Role string `json:"role"`
+}
+
+type cast struct {
+	Name string `json:"name"`
+	URL  string `json:"url"`
+	Role string `json:"role"`
+}
+
+type crew struct {
+	Name string `json:"name"`
+	URL  string `json:"url"`
+	Role string `json:"role"`
+}
+
+func (c cast) GetName() string {
+	return c.Name
+}
+
+func (c crew) GetName() string {
+	return c.Name
+}
+func (c cast) GetURL() string {
+	return c.URL
+}
+
+func (c crew) GetURL() string {
+	return c.URL
+}
+
+func (c cast) GetRole() string {
+	return c.Role
+}
+func (c crew) GetRole() string {
+	return c.Role
+}
+
+const source = "http://data.moviebuff.com/"
+
+type MovieBuff struct {
+	Source, Destination string
+	Person1, Person2    *personInfo
+	Person2Movies       map[string]movie
+	VisitedPerson       map[string]bool
+	Visit               []string
+	Visited             map[string]bool
+	Link                map[string]dos
+	Mutex               sync.Mutex
+}
+
+var (
+	movieBuff    MovieBuff
+)
+
+func main() {
+	args := os.Args[1:]
+
+	if len(args) != 2 {
+		log.Fatalln("Please provide two actor names")
+	}
+
+	if args[0] == args[1] {
+		log.Fatalln("Degree of separation: 0 (Same actor)")
+	}
+
+	movieBuff.Person2Movies, movieBuff.Visited, movieBuff.Link, movieBuff.VisitedPerson = make(map[string]movie), make(map[string]bool), make(map[string]dos), make(map[string]bool)
+
+	if err := processPersonData(args[0], args[1]); err != nil {
+		log.Fatalln(err.Error())
+	}
+
+	t1 := time.Now()
+
+	// Use a channel to signal when the processing is done
+	done := make(chan struct{})
+	defer close(done)
+
+	// Print dots in a separate goroutine
+	go printDots(done)
+
+	// Process data and find the degree of separation
+	dos, err := findDos()
+	if err != nil {
+		log.Fatalln(err.Error())
+	}
+
+	t2 := time.Now()
+
+	// Print the results
+	fmt.Printf("\nDegree of separation: %d\n\n", len(dos))
+	for i, d := range dos {
+		fmt.Printf("%d. Movie: %s\n   %s: %s\n   %s: %s\n\n", i+1, d.Movie, d.Role1, d.Person1, d.Role2, d.Person2)
+	}
+
+	fmt.Println("Total Time taken: ", t2.Sub(t1))
+}
+
+func processPersonData(person1, person2 string) error {
+	pn1, err := fetchData(person1)
+	if err != nil {
+		return err
+	}
+
+	pn2, err := fetchData(person2)
+	if err != nil {
+		return err
+	}
+
+	movieBuff.Mutex.Lock()
+	defer movieBuff.Mutex.Unlock()
+
+	if len(pn1.Movies) > len(pn2.Movies) {
+		movieBuff.Source, movieBuff.Destination = person2, person1
+		movieBuff.Person1, movieBuff.Person2 = pn2, pn1
+	} else {
+		movieBuff.Source, movieBuff.Destination = person1, person2
+		movieBuff.Person1, movieBuff.Person2 = pn1, pn2
+	}
+
+	for _, movie := range movieBuff.Person2.Movies {
+		movieBuff.Person2Movies[movie.URL] = movie
+	}
+
+	movieBuff.Visit = append(movieBuff.Visit, movieBuff.Source)
+	movieBuff.Visited[movieBuff.Source] = true
+
+	return nil
+}
+
+func findDos() ([]dos, error) {
+	var d []dos
+	for {
+		for _, person := range movieBuff.Visit {
+			person1, err := fetchData(person)
+			if err != nil {
+				if isEOFError(err) {
+					continue
+				}
+				continue
+			}
+
+			for _, p1movie := range person1.Movies {
+				if movieBuff.Person2Movies[p1movie.URL].URL == p1movie.URL {
+					if _, found := movieBuff.Link[person1.URL]; found {
+						d = append(d, movieBuff.Link[person1.URL], dos{
+							p1movie.Name, person1.Name, p1movie.Role,
+							movieBuff.Person2.Name, movieBuff.Person2Movies[p1movie.URL].Role,
+						})
+					} else {
+						d = append(d, dos{
+							p1movie.Name, person1.Name, p1movie.Role,
+							movieBuff.Person2.Name, movieBuff.Person2Movies[p1movie.URL].Role,
+						})
+					}
+					return d, nil
+				}
+			}
+
+			for _, p1movie := range person1.Movies {
+				if movieBuff.Visited[p1movie.URL] {
+					continue
+				}
+
+				movieBuff.Visited[p1movie.URL] = true
+
+				p1moviedetail, err := fetchData(p1movie.URL)
+				if err != nil {
+					if isEOFError(err) {
+						continue
+					}
+					continue
+				}
+
+				addToVisit(
+					movieMemberWrapper{Members: castToMovieMember(movieBuff.Person1.Cast)},
+					movieMemberWrapper{Members: crewToMovieMember(movieBuff.Person1.Crew)},
+					movieMemberWrapper{Members: castToMovieMember(person1.Cast)},
+					movieMemberWrapper{Members: crewToMovieMember(person1.Crew)},
+				)
+
+				for _, p1moviecast := range p1moviedetail.Cast {
+					if movieBuff.Visited[p1moviecast.URL] {
+						continue
+					}
+
+					movieBuff.Visited[p1moviecast.URL] = true
+					movieBuff.Visit = append(movieBuff.Visit, p1moviecast.URL)
+					movieBuff.Link[p1moviecast.URL] = dos{
+						p1movie.Name, person1.Name, p1movie.Role, p1moviecast.Name, p1moviecast.Role,
+					}
+				}
+
+				for _, p1moviecrew := range p1moviedetail.Crew {
+					if movieBuff.Visited[p1moviecrew.URL] {
+						continue
+					}
+
+					movieBuff.Visited[p1moviecrew.URL] = true
+					movieBuff.Visit = append(movieBuff.Visit, p1moviecrew.URL)
+					movieBuff.Link[p1moviecrew.URL] = dos{
+						p1movie.Name, person1.Name, p1movie.Role, p1moviecrew.Name, p1moviecrew.Role,
+					}
+				}
+			}
+		}
+	}
+}
+
+func fetchData(url string) (*personInfo, error) {
+	resp, err := http.Get(source + url)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+	result, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	var pi personInfo
+	err = json.Unmarshal(result, &pi)
+	if err != nil {
+		return nil, errors.New("Please provide valid actor name input")
+	}
+
+	return &pi, nil
+}
+
+func addToVisit(members ...movieMemberWrapper) {
+	for _, member := range members {
+		for _, m := range member.Members {
+			movieBuff.Visit = append(movieBuff.Visit, m.GetURL())
+			movieBuff.Link[m.GetURL()] = dos{}
+		}
+	}
+}
+
+func isEOFError(err error) bool {
+	return err != nil && err.Error() == "EOF"
+}
+
+func castToMovieMember(castList []cast) []movieMember {
+	var members []movieMember
+	for _, c := range castList {
+		members = append(members, movieMember(c))
+	}
+	return members
+}
+
+func crewToMovieMember(crewList []crew) []movieMember {
+	var members []movieMember
+	for _, c := range crewList {
+		members = append(members, movieMember(c))
+	}
+	return members
+}
+
+// Function to print dots until done signal is received
+func printDots(done <-chan struct{}) {
+	message := "Degree of separation is being calculated. Please wait"
+	duration := 1 * time.Second // half second
+
+	fmt.Print(message)
+
+	for {
+		select {
+		case <-time.After(duration):
+			fmt.Print(".")
+		case <-done:
+			return
+		}
+	}
+}