package main

import (
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"slices"
	"strings"
	"testing"
)

func TestListRepositoryUsersCombinesReviewerAndAssigneeEligibility(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		var request graphQLRequest
		if err := json.NewDecoder(r.Body).Decode(&request); err != nil {
			t.Fatal(err)
		}
		switch {
		case strings.Contains(request.Query, "RepositoryReviewers"):
			if request.Variables["after"] == nil {
				_, _ = w.Write([]byte(`{"data":{"repository":{"collaborators":{
					"pageInfo":{"hasNextPage":true,"endCursor":"next"},
					"nodes":[
						{"id":"u1","login":"alice","name":"Alice"},
						{"id":"u2","login":"bob","name":"Bob"}
					]
				}}}}`))
			} else {
				_, _ = w.Write([]byte(`{"data":{"repository":{"collaborators":{
					"pageInfo":{"hasNextPage":false},
					"nodes":[{"id":"u4","login":"dave","name":"Dave"}]
				}}}}`))
			}
		case strings.Contains(request.Query, "RepositoryAssignees"):
			_, _ = w.Write([]byte(`{"data":{"repository":{"assignableUsers":{
				"pageInfo":{"hasNextPage":false},
				"nodes":[
					{"id":"u2","login":"bob","name":"Bob"},
					{"id":"u3","login":"carol","name":"Carol"}
				]
			}}}}`))
		case strings.Contains(request.Query, "RepositoryContributions"):
			_, _ = w.Write([]byte(`{"data":{"repository":{"defaultBranchRef":{"target":{"history":{
				"nodes":[
					{"committedDate":"2026-07-28T12:00:00Z","additions":42,
						"author":{"user":{"login":"alice"}}},
					{"committedDate":"2026-07-27T12:00:00Z","additions":8,
						"author":{"user":{"login":"alice"}}},
					{"committedDate":"2026-06-01T12:00:00Z","additions":5,
						"author":{"user":{"login":"bob"}}}
				]
			}}}}}}`))
		default:
			t.Fatalf("unexpected query: %s", request.Query)
		}
	}))
	defer server.Close()

	client := NewGitHubClient(server.URL, "token")
	users, err := client.ListRepositoryUsers(context.Background(), "o", "r")
	if err != nil {
		t.Fatal(err)
	}
	if len(users) != 4 || users[0].Login != "alice" || !users[0].CanReview ||
		users[0].CanAssign || users[1].Login != "bob" ||
		!users[1].CanReview || !users[1].CanAssign ||
		users[2].Login != "carol" || users[2].CanReview || !users[2].CanAssign ||
		users[3].Login != "dave" || !users[3].CanReview {
		t.Fatalf("repository users = %#v", users)
	}
	if users[0].RecentCommits != 2 || users[0].RecentAdditions != 50 ||
		users[0].LastContributionAt.IsZero() || users[1].RecentCommits != 1 {
		t.Fatalf("repository activity = %#v", users)
	}
}

func TestAllAssigneesPaginates(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		var request graphQLRequest
		if err := json.NewDecoder(r.Body).Decode(&request); err != nil {
			t.Fatal(err)
		}
		if !strings.Contains(request.Query, "AssigneesPage") {
			t.Fatalf("unexpected query: %s", request.Query)
		}
		_, _ = w.Write([]byte(`{"data":{"repository":{"pullRequest":{"assignees":{
			"pageInfo":{"hasNextPage":false},
			"nodes":[{"id":"u2","login":"bob","name":"Bob"}]
		}}}}}`))
	}))
	defer server.Close()

	client := NewGitHubClient(server.URL, "token")
	users, err := client.allAssignees(
		context.Background(), "o", "r", 1,
		githubUserConnection{
			PageInfo: githubPageInfo{HasNextPage: true, EndCursor: "next"},
			Nodes:    []githubActor{{Login: "alice"}},
		},
	)
	if err != nil {
		t.Fatal(err)
	}
	if len(users) != 2 || users[0].Login != "alice" || users[1].Login != "bob" {
		t.Fatalf("assignees = %#v", users)
	}
}

func TestUpdatePullRequestPeoplePreservesUnchangedReviewers(t *testing.T) {
	var requests []string
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		var input struct {
			Reviewers []string `json:"reviewers"`
			Assignees []string `json:"assignees"`
		}
		if err := json.NewDecoder(r.Body).Decode(&input); err != nil {
			t.Fatal(err)
		}
		switch {
		case strings.HasSuffix(r.URL.Path, "/requested_reviewers"):
			requests = append(requests, r.Method+":"+strings.Join(input.Reviewers, ","))
		case strings.HasSuffix(r.URL.Path, "/issues/7"):
			requests = append(requests, r.Method+":"+strings.Join(input.Assignees, ","))
		default:
			t.Fatalf("unexpected REST path: %s", r.URL.Path)
		}
		_, _ = w.Write([]byte(`{}`))
	}))
	defer server.Close()

	client := NewGitHubClient(server.URL+"/api/graphql", "token")
	people, err := client.UpdatePullRequestPeople(
		context.Background(), "o", "r", 7,
		PullRequestPeopleUpdate{
			CurrentReviewers: []string{"keep", "remove"},
			CurrentAssignees: []string{"alice"},
			Reviewers:        []string{"keep", "add"},
			Assignees:        []string{"alice", "bob"},
		},
	)
	if err != nil {
		t.Fatal(err)
	}
	want := []string{"POST:add", "DELETE:remove", "PATCH:alice,bob"}
	if !slices.Equal(requests, want) {
		t.Fatalf("REST requests = %v, want %v", requests, want)
	}
	if !slices.Equal(people.Reviewers, []string{"keep", "add"}) ||
		!slices.Equal(people.Assignees, []string{"alice", "bob"}) {
		t.Fatalf("updated people = %#v", people)
	}
}

func TestUpdatePullRequestPeopleReportsSuccessfulPartialChanges(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method == http.MethodDelete {
			http.Error(w, "cannot remove", http.StatusUnprocessableEntity)
			return
		}
		_, _ = w.Write([]byte(`{}`))
	}))
	defer server.Close()

	client := NewGitHubClient(server.URL+"/api/graphql", "token")
	people, err := client.UpdatePullRequestPeople(
		context.Background(), "o", "r", 7,
		PullRequestPeopleUpdate{
			CurrentReviewers: []string{"keep", "remove"},
			Reviewers:        []string{"keep", "add"},
		},
	)
	if err == nil || !strings.Contains(err.Error(), "remove reviewers") {
		t.Fatalf("partial update error = %v", err)
	}
	if !equalLoginSets(people.Reviewers, []string{"keep", "remove", "add"}) {
		t.Fatalf("partial reviewer state = %#v", people.Reviewers)
	}
}