package cabana_test

import (
	"context"
	"encoding/json"
	"errors"
	"strings"
	"testing"

	"git.golem15.com/golem15/summercms/modules/backpack"
	"git.golem15.com/golem15/summercms/modules/cabana"
	"git.golem15.com/golem15/summercms/modules/party"
	"git.golem15.com/golem15/summercms/modules/phrasebook"
	"git.golem15.com/golem15/summercms/modules/towel"
)

// Smoke tests of the flat (WinterCMS Sortable) reorder (Phase 18.1 D-17),
// Docker-free: the inference rule and the flat flag. The Postgres routes are
// TestReorderFlatSmoke in catalog_smoke_test.go; TestReorderFlatNodes is the
// unit matrix of the save's node check (plan 18.1-06). No application names
// appear in framework tests.

// TestReorderFlatCompile pins the flat inference: a config_reorder.yaml
// without parentColumn on a record without a parent_id column compiles as
// flat and the list schema says so; maxDepth on it and an explicit
// parentColumn that is not a column fail boot; the tree fixture still
// compiles as a tree whose list schema carries no flat key.
func TestReorderFlatCompile(t *testing.T) {
	const cfg = "controllers/badges/config_reorder.yaml"
	list, err := cabana.CompiledListSchema([]party.Plugin{catalogFSPlugin{fsys: catalogOverlay(t, nil)}}, "acme.catalog.badges")
	if err != nil {
		t.Fatal(err)
	}
	if list.Reorder == nil || !list.Reorder.Flat || list.Reorder.Title != "Reorder badges" {
		t.Fatalf("badges reorder = %+v", list.Reorder)
	}
	raw, err := json.Marshal(list.Reorder)
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(string(raw), `"flat":true`) {
		t.Fatalf("flat list schema JSON: %s", raw)
	}
	if err := activateCatalog(t, catalogFSPlugin{fsys: catalogOverlay(t, nil)}); err != nil {
		t.Fatalf("catalog boot: %v", err)
	}

	src := catalogFile(t, cfg)
	for _, tc := range []struct {
		name, add string
		want      []string
	}{
		{"maxDepth on a flat reorder", "maxDepth: 2\n", []string{cfg, "maxDepth needs a tree reorder"}},
		{"an explicit parentColumn that is not a column", "parentColumn: parent_id\n", []string{cfg, "parentColumn parent_id is not a column of the record"}},
	} {
		t.Run(tc.name, func(t *testing.T) {
			err := activateCatalog(t, catalogFSPlugin{fsys: catalogOverlay(t, map[string]string{cfg: src + tc.add})})
			if err == nil {
				t.Fatal("boot accepted the reorder config")
			}
			for _, part := range tc.want {
				if !strings.Contains(err.Error(), part) {
					t.Fatalf("err = %v, want %q", err, part)
				}
			}
		})
	}

	// The localized list schema (GET .../schema/list) carries the flat flag
	// too, not only the compiled one (deferred defect from plan 18.1-04).
	t.Run("the localized list schema keeps flat", func(t *testing.T) {
		app := backpack.New(nil)
		if err := phrasebook.Activate[party.Plugin](app, nil); err != nil {
			t.Fatal(err)
		}
		tr, ok := app.Lookup[*phrasebook.Translator]()
		if !ok {
			t.Fatal("translator missing")
		}
		view, err := list.Localize(towel.WithLocale(context.Background(), "en"), tr)
		if err != nil {
			t.Fatal(err)
		}
		if view.Reorder == nil || !view.Reorder.Flat || view.Reorder.Title != "Reorder badges" {
			t.Fatalf("localized reorder = %+v", view.Reorder)
		}
		raw, err := json.Marshal(view)
		if err != nil {
			t.Fatal(err)
		}
		if !strings.Contains(string(raw), `"reorder":{"title":"Reorder badges","flat":true}`) {
			t.Fatalf("localized list schema JSON lacks flat: %s", raw)
		}
	})

	t.Run("the tree fixture stays a tree", func(t *testing.T) {
		tree, err := cabana.CompiledListSchema([]party.Plugin{companionsFSPlugin{fsys: companionsOverlay(t, nil)}}, "acme.companions.links")
		if err != nil {
			t.Fatal(err)
		}
		if tree.Reorder == nil || tree.Reorder.Flat {
			t.Fatalf("links reorder = %+v", tree.Reorder)
		}
		raw, err := json.Marshal(tree)
		if err != nil {
			t.Fatal(err)
		}
		if strings.Contains(string(raw), `"flat"`) {
			t.Fatalf("tree list schema carries a flat key: %s", raw)
		}
	})
}

// TestReorderFlatNodes is the unit matrix of the reorder save's node check
// on a flat reorder (D-17), Docker-free: any non-null parent is a 422 on
// nodes with the flat_parent message, a duplicate id or a zero id is a 422,
// a missing or an extra node is the 409 stale set, and a valid set in any
// order passes with no depth or cycle evaluation. The same node lists on a
// tree reorder show what flat mode changes. TestReorderFlatSmoke drives the
// rules over HTTP on Postgres.
func TestReorderFlatNodes(t *testing.T) {
	const flatParent = "A flat reorder has no parents."
	locked := []cabana.AdminReorderNode{{ID: 1, SortOrder: 1}, {ID: 2, SortOrder: 2}, {ID: 3, SortOrder: 3}}
	node := func(id uint64, parent *uint64, sort int64) cabana.AdminReorderNodeInput {
		return cabana.AdminReorderNodeInput{ID: id, ParentID: parent, SortOrder: sort}
	}
	ptr := func(v uint64) *uint64 { return &v }
	nodesError := func(t *testing.T, err error, want string) {
		t.Helper()
		var ve *cabana.ValidationError
		if !errors.As(err, &ve) {
			t.Fatalf("err = %v, want a 422 validation error", err)
		}
		msgs, _ := ve.Details["nodes"].([]string)
		if len(msgs) != 1 || msgs[0] != want || len(ve.Details) != 1 {
			t.Fatalf("details = %#v, want nodes: %q", ve.Details, want)
		}
	}

	t.Run("a reversed set passes", func(t *testing.T) {
		nodes := []cabana.AdminReorderNodeInput{node(3, nil, 1), node(2, nil, 2), node(1, nil, 3)}
		if err := cabana.CheckReorderNodes(true, 0, locked, nodes, flatParent); err != nil {
			t.Fatal(err)
		}
	})
	t.Run("equal and negative sort values pass", func(t *testing.T) {
		nodes := []cabana.AdminReorderNodeInput{node(1, nil, -5), node(2, nil, 0), node(3, nil, 0)}
		if err := cabana.CheckReorderNodes(true, 0, locked, nodes, flatParent); err != nil {
			t.Fatal(err)
		}
	})
	t.Run("a long flat list has no depth or cycle check", func(t *testing.T) {
		var many []cabana.AdminReorderNode
		var nodes []cabana.AdminReorderNodeInput
		for i := uint(1); i <= 200; i++ {
			many = append(many, cabana.AdminReorderNode{ID: i})
			nodes = append(nodes, node(uint64(201-i), nil, int64(i)))
		}
		if err := cabana.CheckReorderNodes(true, 1, many, nodes, flatParent); err != nil {
			t.Fatal(err)
		}
	})
	t.Run("an empty set over no records passes", func(t *testing.T) {
		if err := cabana.CheckReorderNodes(true, 0, nil, nil, flatParent); err != nil {
			t.Fatal(err)
		}
	})

	for _, tc := range []struct {
		name  string
		nodes []cabana.AdminReorderNodeInput
		want  string
	}{
		{"a parent inside the set", []cabana.AdminReorderNodeInput{node(1, nil, 1), node(2, ptr(1), 2), node(3, nil, 3)}, flatParent},
		{"a parent outside the set", []cabana.AdminReorderNodeInput{node(1, nil, 1), node(2, nil, 2), node(3, ptr(99), 3)}, flatParent},
		{"a parent of zero", []cabana.AdminReorderNodeInput{node(1, ptr(0), 1), node(2, nil, 2), node(3, nil, 3)}, flatParent},
		{"its own parent", []cabana.AdminReorderNodeInput{node(1, nil, 1), node(2, nil, 2), node(3, ptr(3), 3)}, flatParent},
		{"a duplicate id", []cabana.AdminReorderNodeInput{node(1, nil, 1), node(2, nil, 2), node(2, nil, 3)}, "The nodes field lists a record twice."},
		{"a zero id", []cabana.AdminReorderNodeInput{node(0, nil, 1), node(2, nil, 2), node(3, nil, 3)}, "The nodes field must list record ids."},
	} {
		t.Run(tc.name+" is a 422", func(t *testing.T) {
			nodesError(t, cabana.CheckReorderNodes(true, 0, locked, tc.nodes, flatParent), tc.want)
		})
	}

	for _, tc := range []struct {
		name  string
		nodes []cabana.AdminReorderNodeInput
	}{
		{"a missing node", []cabana.AdminReorderNodeInput{node(1, nil, 1), node(2, nil, 2)}},
		{"an extra node", []cabana.AdminReorderNodeInput{node(1, nil, 1), node(2, nil, 2), node(3, nil, 3), node(4, nil, 4)}},
		{"a node swapped for another", []cabana.AdminReorderNodeInput{node(1, nil, 1), node(2, nil, 2), node(4, nil, 3)}},
		{"no nodes", nil},
	} {
		t.Run(tc.name+" is the 409 stale set", func(t *testing.T) {
			err := cabana.CheckReorderNodes(true, 0, locked, tc.nodes, flatParent)
			if !cabana.IsReorderStale(err) {
				t.Fatalf("err = %v, want the stale set", err)
			}
		})
	}

	t.Run("the same parent is accepted on a tree", func(t *testing.T) {
		nodes := []cabana.AdminReorderNodeInput{node(1, nil, 1), node(2, ptr(1), 2), node(3, nil, 3)}
		if err := cabana.CheckReorderNodes(false, 0, locked, nodes, flatParent); err != nil {
			t.Fatal(err)
		}
		cycle := []cabana.AdminReorderNodeInput{node(1, ptr(2), 1), node(2, ptr(1), 2), node(3, nil, 3)}
		nodesError(t, cabana.CheckReorderNodes(false, 0, locked, cycle, flatParent), "The tree has a cycle.")
		deep := []cabana.AdminReorderNodeInput{node(1, nil, 1), node(2, ptr(1), 2), node(3, ptr(2), 3)}
		nodesError(t, cabana.CheckReorderNodes(false, 2, locked, deep, flatParent), "The tree may be at most 2 levels deep.")
	})
}