package bm_test

import (
	"bytes"
	"encoding/json"
	"io"
	"maps"
	"net/http"
	"net/http/httptest"
	"strconv"
	"testing"

	userclasses "git.golem15.com/golem15/sm-user-plugin/classes"
	"git.golem15.com/golem15/summercms/modules/surf"
	"git.golem15.com/jakub/sm-bm-plugin/models"
)

// TestMaterialRevisionAgainstDatabase checks the revision of materials
// through the management API (D-01..D-05): a new material is at revision 1;
// a write with a stale revision is a 409 with the current version and
// changes nothing; a write without revision overwrites; only content
// changes bump; and the student detail shows the same revision.
func TestMaterialRevisionAgainstDatabase(t *testing.T) {
	app, plugins, db := migrated(t)
	seedFixture(t, plugins, "testdata/seed.example.json")

	var courses []models.Course
	if err := db.Order("id").Limit(2).Find(&courses).Error; err != nil {
		t.Fatal(err)
	}
	if len(courses) < 2 {
		t.Fatalf("the fixture has %d courses, want 2", len(courses))
	}
	userID := createUser(t, db, "bm-revision@example.test")
	var groupID uint
	if err := db.Raw(`
INSERT INTO user_groups (name, code, permissions, created_at, updated_at)
VALUES ('BM materials', 'bm-materials', '{"jz.bm.access_materials":1}', NOW(), NOW())
RETURNING id`).Scan(&groupID).Error; err != nil {
		t.Fatal(err)
	}
	if err := db.Exec(`INSERT INTO users_groups (user_id, user_group_id) VALUES (?, ?)`, userID, groupID).Error; err != nil {
		t.Fatal(err)
	}
	secret, token, err := userclasses.MintAPIToken("usr_", userID, "BM notes", []string{"read", "write"}, nil, nil)
	if err != nil {
		t.Fatal(err)
	}
	if err := db.Create(token).Error; err != nil {
		t.Fatal(err)
	}
	handler, err := surf.Assemble(app, plugins)
	if err != nil {
		t.Fatal(err)
	}
	student := apiClient{t: t, h: handler, token: tokenFor(t, userID)}

	send := func(method, path string, payload any) (int, map[string]any) {
		t.Helper()
		var rd io.Reader
		if payload != nil {
			raw, err := json.Marshal(payload)
			if err != nil {
				t.Fatal(err)
			}
			rd = bytes.NewReader(raw)
		}
		req := httptest.NewRequest(method, path, rd)
		req.Header.Set("Authorization", "Bearer "+secret)
		if payload != nil {
			req.Header.Set("Content-Type", "application/json")
		}
		rec := httptest.NewRecorder()
		handler.ServeHTTP(rec, req)
		var out map[string]any
		if rec.Body.Len() > 0 {
			_ = json.Unmarshal(rec.Body.Bytes(), &out)
		}
		return rec.Code, out
	}
	data := func(out map[string]any) map[string]any {
		t.Helper()
		d, _ := out["data"].(map[string]any)
		if d == nil {
			t.Fatalf("no data object in %v", out)
		}
		return d
	}

	note := map[string]any{"title": "Rewizje", "type": "notatka", "course_id": courses[0].ID, "body": "pierwsza\n", "tags": []string{"Globalizacja"}}
	code, out := send(http.MethodPost, "/api/v1/bm/materials", note)
	if code != http.StatusCreated {
		t.Fatalf("create = %d %v", code, out)
	}
	created := data(out)
	if created["revision"] != float64(1) || created["updated_at"] == nil {
		t.Fatalf("created = %v, want revision 1 and updated_at", created)
	}
	path := "/api/v1/bm/materials/" + strconv.Itoa(int(created["id"].(float64)))
	studentPath := "/_bm/api/v1/materials/" + strconv.Itoa(int(created["id"].(float64)))

	revisionOf := func() float64 {
		t.Helper()
		code, out := send(http.MethodGet, path, nil)
		if code != http.StatusOK {
			t.Fatalf("show = %d %v", code, out)
		}
		r, _ := data(out)["revision"].(float64)
		return r
	}
	if r := revisionOf(); r != 1 {
		t.Fatalf("new material revision = %v, want 1", r)
	}
	with := func(changes map[string]any) map[string]any {
		out := maps.Clone(note)
		maps.Copy(out, changes)
		return out
	}

	code, out = send(http.MethodPut, path, with(map[string]any{"body": "druga\n", "revision": 1}))
	if code != http.StatusOK || data(out)["revision"] != float64(2) {
		t.Fatalf("PUT with the current revision = %d %v, want 200 and revision 2", code, out)
	}
	note["body"] = "druga\n"

	code, out = send(http.MethodPut, path, with(map[string]any{"body": "nieaktualna\n", "revision": 1}))
	if code != http.StatusConflict {
		t.Fatalf("PUT with a stale revision = %d %v, want 409", code, out)
	}
	if out["error"] != true || out["revision"] != float64(2) || out["updated_at"] == nil || out["message"] == nil {
		t.Errorf("409 body = %v, want error, message, revision 2 and updated_at", out)
	}
	if data(out)["body"] != "druga\n" {
		t.Errorf("409 data.body = %v, want the stored body", data(out)["body"])
	}
	var stored models.Material
	if err := db.First(&stored, created["id"]).Error; err != nil {
		t.Fatal(err)
	}
	if stored.Body == nil || *stored.Body != "druga\n" || stored.Revision != 2 {
		t.Errorf("after the 409 the row is body %v revision %d, want unchanged", stored.Body, stored.Revision)
	}

	code, out = send(http.MethodPut, path, with(map[string]any{"body": "trzecia\n"}))
	if code != http.StatusOK || data(out)["revision"] != float64(3) {
		t.Fatalf("PUT without revision = %d %v, want 200 and revision 3", code, out)
	}
	note["body"] = "trzecia\n"

	for name, changes := range map[string]map[string]any{
		"published_at only":  {"published_at": "2026-10-01T10:00:00+02:00"},
		"is_private only":    {"is_private": true},
		"identical content":  {},
		"identical, current": {"revision": 3},
	} {
		code, out = send(http.MethodPut, path, with(changes))
		if code != http.StatusOK || data(out)["revision"] != float64(3) {
			t.Errorf("PUT with %s = %d %v, want 200 and revision 3", name, code, out)
		}
	}

	code, out = send(http.MethodPut, path, with(map[string]any{"tags": []string{"Globalizacja", "Teoria"}}))
	if code != http.StatusOK || data(out)["revision"] != float64(4) {
		t.Fatalf("PUT changing the tags = %d %v, want revision 4", code, out)
	}
	note["tags"] = []string{"Teoria", "Globalizacja"}
	code, out = send(http.MethodPut, path, note)
	if code != http.StatusOK || data(out)["revision"] != float64(4) {
		t.Errorf("PUT with the same tags reordered = %d %v, want revision 4", code, out)
	}
	code, out = send(http.MethodPut, path, with(map[string]any{"course_id": courses[1].ID}))
	if code != http.StatusOK || data(out)["revision"] != float64(5) {
		t.Fatalf("PUT changing the course = %d %v, want revision 5", code, out)
	}
	note["course_id"] = courses[1].ID

	detail := obj(student.ok(http.MethodGet, studentPath)["data"])
	if detail["revision"] != float64(5) {
		t.Errorf("student detail revision = %v, want 5", detail["revision"])
	}
}