package client

import (
	"context"
	"errors"
	"net/http"
	"os"
	"path/filepath"
	"testing"
	"time"

	"lodge/internal/gitrepo"
	"lodge/internal/protocol"
)

func issueCode(t *testing.T, url string) string {
	t.Helper()
	var code protocol.CodeResponse
	admin := &Client{URL: url, Token: adminToken}
	if err := admin.call(context.Background(), http.MethodPost, "/api/codes", nil, &code); err != nil {
		t.Fatal(err)
	}
	return code.Code
}

func (m *machine) remote(url, code string) {
	m.t.Helper()
	ctx := context.Background()
	if code != "" {
		if err := m.config.Connect(ctx, url, code); err != nil {
			m.t.Fatal(err)
		}
	}
	if err := m.config.Bind(repoKey(m.t, m), url); err != nil {
		m.t.Fatal(err)
	}
	m.sync()
}

func revisionsOn(t *testing.T, url, key string) []protocol.Revision {
	t.Helper()
	revisions, err := (&Client{URL: url, Token: adminToken}).Revisions(context.Background(), key, "")
	if err != nil {
		t.Fatal(err)
	}
	return revisions
}

func TestBoundRepositoryNeverReachesTheDefaultServer(t *testing.T) {
	personal, event, origin := newServer(t), newServer(t), newOrigin(t)
	mac := newMachine(t, origin, personal, adminToken)
	key := repoKey(t, mac)
	ctx := context.Background()

	if err := mac.config.Hook(ctx, mac.root); err != nil {
		t.Fatal(err)
	}
	stale, err := mac.config.reload()
	if err != nil {
		t.Fatal(err)
	}
	mac.remote(event+"/", issueCode(t, event))
	write(t, mac.root, "docs/agents/plan.md", "event plan")
	if _, err := stale.Sync(ctx, mac.root, true); err != nil {
		t.Fatal(err)
	}

	worktree := filepath.Join(t.TempDir(), "feature")
	git(t, mac.root, "worktree", "add", "-b", "feature", worktree)
	worktree, _ = filepath.EvalSymlinks(worktree)
	if err := mac.config.Hook(ctx, worktree); err != nil {
		t.Fatal(err)
	}
	if data, _ := os.ReadFile(filepath.Join(worktree, "docs/agents/plan.md")); string(data) != "event plan" {
		t.Fatalf("new worktree of a bound repository got %q", data)
	}

	other := newMachine(t, newOrigin(t), personal, adminToken)
	other.config = mac.config
	write(t, other.root, "docs/agents/private.md", "personal")
	other.sync()

	if revisions := revisionsOn(t, personal, key); len(revisions) != 0 {
		t.Fatalf("the default server received %d revisions of a bound repository", len(revisions))
	}
	if revisions := revisionsOn(t, event, key); len(revisions) != 1 {
		t.Fatalf("the event server has %d revisions, want 1", len(revisions))
	}
	if revisions := revisionsOn(t, event, repoKey(t, other)); len(revisions) != 0 {
		t.Fatal("an unbound repository reached the event server")
	}
	if revisions := revisionsOn(t, personal, repoKey(t, other)); len(revisions) != 1 {
		t.Fatal("an unbound repository did not reach the default server")
	}

	if c, err := mac.config.Server(key); err != nil || c.URL != event {
		t.Fatalf("server of the bound repository = %v (%v), want %s", c, err, event)
	}
}

func TestMachineWithoutDefaultServer(t *testing.T) {
	event, origin := newServer(t), newOrigin(t)
	mac := newMachine(t, origin, event, adminToken)
	write(t, mac.root, "docs/agents/plan.md", "plan")
	mac.sync()

	fresh := newMachine(t, origin, "", "")
	if _, err := fresh.config.Sync(context.Background(), fresh.root, true); !errors.Is(err, ErrNotLoggedIn) {
		t.Fatalf("sync without any server: %v", err)
	}
	if roots := fresh.config.Worktrees(); len(roots) != 0 {
		t.Fatalf("a repository without a server was registered: %v", roots)
	}
	if err := fresh.config.Connect(context.Background(), event, issueCode(t, event)); err != nil {
		t.Fatal(err)
	}
	fresh.remote(event, "")
	fresh.expect("docs/agents/plan.md", "plan")
	if fresh.config.URL != "" {
		t.Fatalf("lodge remote set the default server to %q", fresh.config.URL)
	}
}

func TestMovingBetweenServersKeepsLocalFiles(t *testing.T) {
	personal, event, origin := newServer(t), newServer(t), newOrigin(t)
	mac := newMachine(t, origin, personal, adminToken)
	dell := newMachine(t, origin, "", "")
	key := repoKey(t, mac)

	write(t, mac.root, "docs/agents/mine.md", "mine")
	mac.sync()
	dell.remote(event, issueCode(t, event))
	write(t, dell.root, "docs/agents/theirs.md", "theirs")
	dell.sync()

	mac.remote(event, issueCode(t, event))
	mac.expect("docs/agents/mine.md", "mine")
	mac.expect("docs/agents/theirs.md", "theirs")
	dell.sync()
	dell.expect("docs/agents/mine.md", "mine")

	if err := mac.config.Bind(key, ""); err != nil {
		t.Fatal(err)
	}
	mac.sync()
	mac.expect("docs/agents/mine.md", "mine")
	mac.expect("docs/agents/theirs.md", "theirs")
	state, err := mac.client.State(context.Background(), key, "")
	if err != nil || len(state.Spaces[protocol.SharedSpace]) != 2 {
		t.Fatalf("back on the default server: %v (%v)", state.Spaces, err)
	}
}

func TestStateFromBeforeServersIsAdopted(t *testing.T) {
	mac, dell := setup(t)
	write(t, mac.root, "docs/agents/plan.md", "plan")
	mac.sync()
	dell.sync()
	repo := openRepo(t, mac)
	if err := os.Rename(mac.client.statePath(repo), worktreePath(mac.config.DataDir, repo)+".json"); err != nil {
		t.Fatal(err)
	}
	if err := os.Remove(filepath.Join(dell.root, "docs/agents/plan.md")); err != nil {
		t.Fatal(err)
	}
	dell.sync()
	mac.sync()
	mac.expect("docs/agents/plan.md", "")
}

func TestDaemonFollowsServersAddedLater(t *testing.T) {
	event, origin := newServer(t), newOrigin(t)
	mac := newMachine(t, origin, event, adminToken)
	fresh := newMachine(t, origin, "", "")
	daemonConfig, err := fresh.config.reload()
	if err != nil {
		t.Fatal(err)
	}
	ctx, cancel := context.WithCancel(context.Background())
	done := make(chan error)
	go func() { done <- daemonConfig.Daemon(ctx) }()
	t.Cleanup(func() {
		cancel()
		if err := <-done; err != nil {
			t.Error(err)
		}
	})

	fresh.remote(event, issueCode(t, event))
	write(t, mac.root, "docs/agents/first.md", "first")
	mac.sync()
	fresh.waitFor("docs/agents/first.md", "first")
	write(t, mac.root, "docs/agents/second.md", "second")
	mac.sync()
	fresh.waitFor("docs/agents/second.md", "second")
}

func (m *machine) waitFor(path, content string) {
	m.t.Helper()
	deadline := time.Now().Add(15 * time.Second)
	for {
		if data, _ := os.ReadFile(filepath.Join(m.root, path)); string(data) == content {
			return
		}
		if time.Now().After(deadline) {
			m.t.Fatalf("the daemon did not bring %s", path)
		}
		time.Sleep(50 * time.Millisecond)
	}
}

func openRepo(t *testing.T, m *machine) *gitrepo.Repo {
	t.Helper()
	repo, err := gitrepo.Open(m.root)
	if err != nil {
		t.Fatal(err)
	}
	return repo
}