package allocator

import (
	"context"
	"errors"
	"testing"
	"time"

	"github.com/cosmic-clash/cosmic-clash/server/agones"
	"github.com/cosmic-clash/cosmic-clash/server/domain"
)

type providerSpy struct {
	calls  int
	result agones.AllocatedServer
	err    error
}

func (p *providerSpy) Allocate(_ context.Context, _ domain.AllocationRequest, _ map[string]string, _ time.Time) (agones.AllocatedServer, error) {
	p.calls++
	return p.result, p.err
}

type durableSpy struct {
	calls      int
	allocation domain.Allocation
	err        error
}

type rosterSpy struct {
	calls int
	err   error
}

func (r *rosterSpy) PublishRoster(_ context.Context, _ domain.Assignment, _ []domain.SignedJoinAuthorisation, _ func([]byte, []byte) bool) error {
	r.calls++
	return r.err
}

func (d *durableSpy) RecordProviderAllocation(_ context.Context, allocation domain.Allocation, _ time.Time) (domain.Allocation, error) {
	d.calls++
	d.allocation = allocation
	return allocation, d.err
}

func TestServiceDurablyRecordsProviderAllocationBeforeReturning(t *testing.T) {
	provider := &providerSpy{result: agones.AllocatedServer{Allocation: domain.Allocation{AllocationID: "a", MatchID: "m", ServerID: "gs", State: domain.ServerAllocated}, Endpoint: "127.0.0.1:7777"}}
	durable := &durableSpy{}
	service := Service{Provider: provider, Durable: durable, Now: func() time.Time { return time.Unix(1000, 0) }}
	result, err := service.Allocate(context.Background(), domain.AllocationRequest{AllocationID: "a", MatchID: "m", Region: "EU", Build: "b", Protocol: 1, Transport: "enet"}, map[string]string{"region": "EU"})
	if err != nil || result.Endpoint == "" || durable.calls != 1 || durable.allocation.ServerID != "gs" {
		t.Fatalf("result=%+v err=%v durable=%+v", result, err, durable)
	}
}

func TestServiceDoesNotReturnProviderResultAfterDurableFailure(t *testing.T) {
	provider := &providerSpy{result: agones.AllocatedServer{Allocation: domain.Allocation{AllocationID: "a", State: domain.ServerAllocated}, Endpoint: "127.0.0.1:7777"}}
	durable := &durableSpy{err: errors.New("database unavailable")}
	service := Service{Provider: provider, Durable: durable, Now: func() time.Time { return time.Unix(1000, 0) }}
	result, err := service.Allocate(context.Background(), domain.AllocationRequest{AllocationID: "a", MatchID: "m", Region: "EU", Build: "b", Protocol: 1, Transport: "enet"}, map[string]string{"region": "EU"})
	if err == nil || result.Endpoint != "" || durable.calls != 1 {
		t.Fatalf("result=%+v err=%v calls=%d", result, err, durable.calls)
	}
}

func TestServiceAllocatesOnlyUnanimouslyAcceptedMatchingProposal(t *testing.T) {
	proposal := domain.Proposal{
		ProposalID: "proposal-1", Playlist: domain.Casual, State: domain.Accepted,
		Participants: []domain.ProposalParticipant{
			{PlayerID: "player-a", Response: domain.AcceptedResponse},
			{PlayerID: "player-b", Response: domain.AcceptedResponse},
		},
	}
	provider := &providerSpy{result: agones.AllocatedServer{Allocation: domain.Allocation{AllocationID: "a", MatchID: "m", State: domain.ServerAllocated}, Endpoint: "127.0.0.1:7777"}}
	durable := &durableSpy{}
	service := Service{Provider: provider, Durable: durable, Now: func() time.Time { return time.Unix(1000, 0) }}
	request := domain.AllocationRequest{AllocationID: "a", MatchID: "m", Region: "EU", Build: "b", Protocol: 1, Transport: "enet"}
	if _, err := service.AllocateAcceptedProposal(context.Background(), proposal, request, domain.Casual, map[string]string{"region": "EU"}); err != nil {
		t.Fatalf("accepted proposal was rejected: %v", err)
	}
	if provider.calls != 1 || durable.calls != 1 {
		t.Fatalf("provider/durable calls = %d/%d", provider.calls, durable.calls)
	}

	for name, mutate := range map[string]func(*domain.Proposal){
		"open":           func(p *domain.Proposal) { p.State = domain.Open },
		"wrong-playlist": func(p *domain.Proposal) { p.Playlist = domain.Ranked },
		"pending":        func(p *domain.Proposal) { p.Participants[0].Response = domain.Pending },
		"duplicate":      func(p *domain.Proposal) { p.Participants[1].PlayerID = p.Participants[0].PlayerID },
	} {
		invalid := proposal
		invalid.Participants = append([]domain.ProposalParticipant(nil), proposal.Participants...)
		mutate(&invalid)
		before := provider.calls
		if _, err := service.AllocateAcceptedProposal(context.Background(), invalid, request, domain.Casual, map[string]string{"region": "EU"}); err == nil {
			t.Fatalf("%s proposal was accepted", name)
		}
		if provider.calls != before {
			t.Fatalf("%s proposal reached provider", name)
		}
	}
}

func TestServicePublishesRosterOnlyForAllocatedAssignment(t *testing.T) {
	roster := &rosterSpy{}
	service := Service{Roster: roster}
	assignment := domain.Assignment{Allocation: domain.Allocation{State: domain.ServerAllocated}, Endpoint: "127.0.0.1:7777"}
	if err := service.PublishRoster(context.Background(), assignment, []domain.SignedJoinAuthorisation{{Signature: []byte("sig")}}, func([]byte, []byte) bool { return true }); err != nil || roster.calls != 1 {
		t.Fatalf("publish err=%v calls=%d", err, roster.calls)
	}
	assignment.Allocation.State = domain.ServerReady
	if err := service.PublishRoster(context.Background(), assignment, nil, nil); err != domain.ErrManifestRejected || roster.calls != 1 {
		t.Fatalf("premature publish err=%v calls=%d", err, roster.calls)
	}
}