package api

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

	"github.com/go-chi/chi/v5"
	"github.com/kindredsystems/silo/internal/db"
	"github.com/kindredsystems/silo/internal/modules"
	"github.com/kindredsystems/silo/internal/schema"
	"github.com/kindredsystems/silo/internal/testutil"
	"github.com/rs/zerolog"
)

func newDAGTestServer(t *testing.T) *Server {
	t.Helper()
	pool := testutil.MustConnectTestPool(t)
	database := db.NewFromPool(pool)
	broker := NewBroker(zerolog.Nop())
	state := NewServerState(zerolog.Nop(), nil, broker)
	return NewServer(
		zerolog.Nop(),
		database,
		map[string]*schema.Schema{},
		"",
		nil, nil, nil, nil, nil,
		broker, state,
		nil, "",
		modules.NewRegistry(), nil,
	)
}

func newDAGRouter(s *Server) http.Handler {
	r := chi.NewRouter()
	r.Route("/api/items/{partNumber}", func(r chi.Router) {
		r.Get("/dag", s.HandleGetDAG)
		r.Get("/dag/forward-cone/{nodeKey}", s.HandleGetForwardCone)
		r.Get("/dag/dirty", s.HandleGetDirtySubgraph)
		r.Put("/dag", s.HandleSyncDAG)
		r.Post("/dag/mark-dirty/{nodeKey}", s.HandleMarkDirty)
	})
	return r
}

func TestHandleGetDAG_Empty(t *testing.T) {
	s := newDAGTestServer(t)
	r := newDAGRouter(s)

	// Create an item
	item := &db.Item{PartNumber: "DAG-TEST-001", ItemType: "part", Description: "DAG test"}
	if err := s.items.Create(context.Background(), item, nil); err != nil {
		t.Fatalf("creating item: %v", err)
	}

	req := httptest.NewRequest("GET", "/api/items/DAG-TEST-001/dag", nil)
	w := httptest.NewRecorder()
	r.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d: %s", w.Code, w.Body.String())
	}

	var resp map[string]any
	json.Unmarshal(w.Body.Bytes(), &resp)
	if resp["part_number"] != "DAG-TEST-001" {
		t.Errorf("expected part_number DAG-TEST-001, got %v", resp["part_number"])
	}
}

func TestHandleSyncDAG(t *testing.T) {
	s := newDAGTestServer(t)
	r := newDAGRouter(s)

	// Create an item with a revision
	item := &db.Item{PartNumber: "DAG-SYNC-001", ItemType: "part", Description: "sync test"}
	if err := s.items.Create(context.Background(), item, nil); err != nil {
		t.Fatalf("creating item: %v", err)
	}

	// Sync a feature tree
	body := `{
		"nodes": [
			{"node_key": "Sketch001", "node_type": "sketch"},
			{"node_key": "Pad001", "node_type": "pad"},
			{"node_key": "Fillet001", "node_type": "fillet"}
		],
		"edges": [
			{"source_key": "Sketch001", "target_key": "Pad001", "edge_type": "depends_on"},
			{"source_key": "Pad001", "target_key": "Fillet001", "edge_type": "depends_on"}
		]
	}`

	req := httptest.NewRequest("PUT", "/api/items/DAG-SYNC-001/dag", strings.NewReader(body))
	req.Header.Set("Content-Type", "application/json")
	w := httptest.NewRecorder()
	r.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d: %s", w.Code, w.Body.String())
	}

	var resp map[string]any
	json.Unmarshal(w.Body.Bytes(), &resp)
	if resp["node_count"] != float64(3) {
		t.Errorf("expected 3 nodes, got %v", resp["node_count"])
	}
	if resp["edge_count"] != float64(2) {
		t.Errorf("expected 2 edges, got %v", resp["edge_count"])
	}

	// Verify we can read the DAG back
	req2 := httptest.NewRequest("GET", "/api/items/DAG-SYNC-001/dag", nil)
	w2 := httptest.NewRecorder()
	r.ServeHTTP(w2, req2)

	if w2.Code != http.StatusOK {
		t.Fatalf("GET dag: expected 200, got %d", w2.Code)
	}
	var dagResp map[string]any
	json.Unmarshal(w2.Body.Bytes(), &dagResp)
	nodes, ok := dagResp["nodes"].([]any)
	if !ok || len(nodes) != 3 {
		t.Errorf("expected 3 nodes in GET, got %v", dagResp["nodes"])
	}
}

func TestHandleForwardCone(t *testing.T) {
	s := newDAGTestServer(t)
	r := newDAGRouter(s)

	item := &db.Item{PartNumber: "DAG-CONE-001", ItemType: "part", Description: "cone test"}
	if err := s.items.Create(context.Background(), item, nil); err != nil {
		t.Fatalf("creating item: %v", err)
	}

	// Sync a linear chain: A -> B -> C
	body := `{
		"nodes": [
			{"node_key": "A", "node_type": "sketch"},
			{"node_key": "B", "node_type": "pad"},
			{"node_key": "C", "node_type": "fillet"}
		],
		"edges": [
			{"source_key": "A", "target_key": "B"},
			{"source_key": "B", "target_key": "C"}
		]
	}`
	req := httptest.NewRequest("PUT", "/api/items/DAG-CONE-001/dag", strings.NewReader(body))
	req.Header.Set("Content-Type", "application/json")
	w := httptest.NewRecorder()
	r.ServeHTTP(w, req)
	if w.Code != http.StatusOK {
		t.Fatalf("sync: %d %s", w.Code, w.Body.String())
	}

	// Forward cone from A should include B and C
	req2 := httptest.NewRequest("GET", "/api/items/DAG-CONE-001/dag/forward-cone/A", nil)
	w2 := httptest.NewRecorder()
	r.ServeHTTP(w2, req2)

	if w2.Code != http.StatusOK {
		t.Fatalf("forward-cone: %d %s", w2.Code, w2.Body.String())
	}

	var resp map[string]any
	json.Unmarshal(w2.Body.Bytes(), &resp)
	cone, ok := resp["cone"].([]any)
	if !ok || len(cone) != 2 {
		t.Errorf("expected 2 nodes in forward cone, got %v", resp["cone"])
	}
}

func TestHandleMarkDirty(t *testing.T) {
	s := newDAGTestServer(t)
	r := newDAGRouter(s)

	item := &db.Item{PartNumber: "DAG-DIRTY-001", ItemType: "part", Description: "dirty test"}
	if err := s.items.Create(context.Background(), item, nil); err != nil {
		t.Fatalf("creating item: %v", err)
	}

	// Sync: A -> B -> C
	body := `{
		"nodes": [
			{"node_key": "X", "node_type": "sketch"},
			{"node_key": "Y", "node_type": "pad"},
			{"node_key": "Z", "node_type": "fillet"}
		],
		"edges": [
			{"source_key": "X", "target_key": "Y"},
			{"source_key": "Y", "target_key": "Z"}
		]
	}`
	req := httptest.NewRequest("PUT", "/api/items/DAG-DIRTY-001/dag", strings.NewReader(body))
	req.Header.Set("Content-Type", "application/json")
	w := httptest.NewRecorder()
	r.ServeHTTP(w, req)
	if w.Code != http.StatusOK {
		t.Fatalf("sync: %d %s", w.Code, w.Body.String())
	}

	// Mark X dirty — should propagate to Y and Z
	req2 := httptest.NewRequest("POST", "/api/items/DAG-DIRTY-001/dag/mark-dirty/X", nil)
	w2 := httptest.NewRecorder()
	r.ServeHTTP(w2, req2)

	if w2.Code != http.StatusOK {
		t.Fatalf("mark-dirty: %d %s", w2.Code, w2.Body.String())
	}

	var resp map[string]any
	json.Unmarshal(w2.Body.Bytes(), &resp)
	affected := resp["nodes_affected"].(float64)
	if affected != 3 {
		t.Errorf("expected 3 nodes affected, got %v", affected)
	}

	// Verify dirty subgraph
	req3 := httptest.NewRequest("GET", "/api/items/DAG-DIRTY-001/dag/dirty", nil)
	w3 := httptest.NewRecorder()
	r.ServeHTTP(w3, req3)

	if w3.Code != http.StatusOK {
		t.Fatalf("dirty: %d %s", w3.Code, w3.Body.String())
	}
	var dirtyResp map[string]any
	json.Unmarshal(w3.Body.Bytes(), &dirtyResp)
	dirtyNodes, ok := dirtyResp["nodes"].([]any)
	if !ok || len(dirtyNodes) != 3 {
		t.Errorf("expected 3 dirty nodes, got %v", dirtyResp["nodes"])
	}
}

func TestHandleGetDAG_NotFound(t *testing.T) {
	s := newDAGTestServer(t)
	r := newDAGRouter(s)

	req := httptest.NewRequest("GET", "/api/items/NONEXISTENT-999/dag", nil)
	w := httptest.NewRecorder()
	r.ServeHTTP(w, req)

	if w.Code != http.StatusNotFound {
		t.Errorf("expected 404, got %d", w.Code)
	}
}