package main

import (
	"database/sql"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"strings"
	"testing"

	_ "github.com/mattn/go-sqlite3"
)

func setupTestDB(t *testing.T) (*DBPool, string) {
	t.Helper()
	dir := t.TempDir()
	dbPath := filepath.Join(dir, "test.db")

	// Create a small test database with FTS5.
	db, err := sql.Open("sqlite3", dbPath)
	if err != nil {
		t.Fatal(err)
	}

	stmts := []string{
		`CREATE TABLE items (id TEXT PRIMARY KEY, name TEXT, kind TEXT)`,
		`INSERT INTO items VALUES ('a', 'alpha', 'first')`,
		`INSERT INTO items VALUES ('b', 'beta', 'second')`,
		`CREATE VIRTUAL TABLE items_fts USING fts5(id, name, kind, content=items, content_rowid=rowid)`,
		`INSERT INTO items_fts(items_fts) VALUES('rebuild')`,
	}
	for _, s := range stmts {
		if _, err := db.Exec(s); err != nil {
			t.Fatalf("setup sql %q: %v", s, err)
		}
	}
	db.Close()

	pool := NewDBPool()
	pool.Register(DBEntry{Alias: "testdb", Path: dbPath, Kind: "test"})
	return pool, dir
}

func TestHealthEndpoint(t *testing.T) {
	pool := NewDBPool()
	srv := NewServer(pool, "")
	mux := http.NewServeMux()
	srv.Routes(mux)

	req := httptest.NewRequest("GET", "/health", nil)
	w := httptest.NewRecorder()
	mux.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d", w.Code)
	}
	var resp map[string]string
	json.NewDecoder(w.Body).Decode(&resp)
	if resp["status"] != "ok" {
		t.Fatalf("expected status ok, got %s", resp["status"])
	}
}

func TestDatabasesEndpoint(t *testing.T) {
	pool := NewDBPool()
	pool.Register(DBEntry{Alias: "registry", Path: "/fake/path", Kind: "registry"})
	pool.Register(DBEntry{Alias: "ops:myapp", Path: "/fake/path2", Kind: "operations"})

	srv := NewServer(pool, "")
	mux := http.NewServeMux()
	srv.Routes(mux)

	req := httptest.NewRequest("GET", "/api/databases", nil)
	w := httptest.NewRecorder()
	mux.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d", w.Code)
	}
	var resp []map[string]string
	json.NewDecoder(w.Body).Decode(&resp)
	if len(resp) != 2 {
		t.Fatalf("expected 2 databases, got %d", len(resp))
	}
}

func TestQueryEndpoint(t *testing.T) {
	pool, _ := setupTestDB(t)
	defer pool.Close()

	srv := NewServer(pool, "")
	mux := http.NewServeMux()
	srv.Routes(mux)

	body := `{"sql": "SELECT id, name FROM items ORDER BY id"}`
	req := httptest.NewRequest("POST", "/api/databases/testdb/query", strings.NewReader(body))
	req.Header.Set("Content-Type", "application/json")
	w := httptest.NewRecorder()
	mux.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.NewDecoder(w.Body).Decode(&resp)
	if int(resp["count"].(float64)) != 2 {
		t.Fatalf("expected 2 rows, got %v", resp["count"])
	}
	cols := resp["columns"].([]any)
	if len(cols) != 2 || cols[0] != "id" || cols[1] != "name" {
		t.Fatalf("unexpected columns: %v", cols)
	}
}

func TestQueryRejectsWrite(t *testing.T) {
	pool, _ := setupTestDB(t)
	defer pool.Close()

	srv := NewServer(pool, "")
	mux := http.NewServeMux()
	srv.Routes(mux)

	cases := []string{
		`{"sql": "INSERT INTO items VALUES ('c', 'gamma', 'third')"}`,
		`{"sql": "UPDATE items SET name = 'x' WHERE id = 'a'"}`,
		`{"sql": "DELETE FROM items WHERE id = 'a'"}`,
		`{"sql": "DROP TABLE items"}`,
	}

	for _, body := range cases {
		req := httptest.NewRequest("POST", "/api/databases/testdb/query", strings.NewReader(body))
		req.Header.Set("Content-Type", "application/json")
		w := httptest.NewRecorder()
		mux.ServeHTTP(w, req)

		if w.Code != http.StatusBadRequest {
			t.Errorf("expected 400 for %s, got %d", body, w.Code)
		}
	}
}

func TestTablesEndpoint(t *testing.T) {
	pool, _ := setupTestDB(t)
	defer pool.Close()

	srv := NewServer(pool, "")
	mux := http.NewServeMux()
	srv.Routes(mux)

	req := httptest.NewRequest("GET", "/api/databases/testdb/tables", nil)
	w := httptest.NewRecorder()
	mux.ServeHTTP(w, req)

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

	var resp []map[string]string
	json.NewDecoder(w.Body).Decode(&resp)
	if len(resp) == 0 {
		t.Fatal("expected at least one table")
	}
	found := false
	for _, tbl := range resp {
		if tbl["name"] == "items" {
			found = true
		}
	}
	if !found {
		t.Fatal("expected 'items' table in response")
	}
}

func TestSchemaEndpoint(t *testing.T) {
	pool, _ := setupTestDB(t)
	defer pool.Close()

	srv := NewServer(pool, "")
	mux := http.NewServeMux()
	srv.Routes(mux)

	req := httptest.NewRequest("GET", "/api/databases/testdb/schema", nil)
	w := httptest.NewRecorder()
	mux.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.NewDecoder(w.Body).Decode(&resp)
	count := int(resp["count"].(float64))
	if count == 0 {
		t.Fatal("expected at least one schema statement")
	}
}

func TestNotFoundDB(t *testing.T) {
	pool := NewDBPool()
	srv := NewServer(pool, "")
	mux := http.NewServeMux()
	srv.Routes(mux)

	body := `{"sql": "SELECT 1"}`
	req := httptest.NewRequest("POST", "/api/databases/nonexistent/query", strings.NewReader(body))
	req.Header.Set("Content-Type", "application/json")
	w := httptest.NewRecorder()
	mux.ServeHTTP(w, req)

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

func TestValidateQuery(t *testing.T) {
	valid := []string{
		"SELECT * FROM t",
		"  select id from t",
		"PRAGMA table_info(t)",
		"WITH cte AS (SELECT 1) SELECT * FROM cte",
		"EXPLAIN SELECT * FROM t",
		"-- comment\nSELECT 1",
	}
	for _, q := range valid {
		if err := ValidateQuery(q); err != nil {
			t.Errorf("expected valid: %q, got error: %v", q, err)
		}
	}

	invalid := []string{
		"INSERT INTO t VALUES (1)",
		"UPDATE t SET x = 1",
		"DELETE FROM t",
		"DROP TABLE t",
		"CREATE TABLE t (id INT)",
		"ALTER TABLE t ADD COLUMN x INT",
	}
	for _, q := range invalid {
		if err := ValidateQuery(q); err == nil {
			t.Errorf("expected invalid: %q, got nil error", q)
		}
	}
}

func TestDiscoverDatabases(t *testing.T) {
	dir := t.TempDir()

	// Create registry.db
	os.WriteFile(filepath.Join(dir, "registry.db"), []byte{}, 0644)

	// Create apps/myapp/operations.db
	os.MkdirAll(filepath.Join(dir, "apps", "myapp"), 0755)
	os.WriteFile(filepath.Join(dir, "apps", "myapp", "operations.db"), []byte{}, 0644)

	// Create projects/proj1/apps/papp/operations.db
	os.MkdirAll(filepath.Join(dir, "projects", "proj1", "apps", "papp"), 0755)
	os.WriteFile(filepath.Join(dir, "projects", "proj1", "apps", "papp", "operations.db"), []byte{}, 0644)

	entries := DiscoverDatabases(dir)
	if len(entries) != 3 {
		t.Fatalf("expected 3 entries, got %d: %+v", len(entries), entries)
	}

	aliases := map[string]bool{}
	for _, e := range entries {
		aliases[e.Alias] = true
	}
	for _, want := range []string{"registry", "ops:myapp", "ops:papp"} {
		if !aliases[want] {
			t.Errorf("missing alias %q", want)
		}
	}
}