package gateway

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

	"git.yeij.top/AskaEth/Cyrene_v2/internal/auth"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/db"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/history"
)

// testLogger returns a logger that writes nowhere, keeping test output clean.
func testLogger() *slog.Logger {
	return slog.New(slog.NewTextHandler(io.Discard, nil))
}

// newHistoryEnv builds a Server wired with a real in-memory history store, returning the
// httptest server, the JWT service and the underlying history store.
func newHistoryEnv(t *testing.T) (*Server, *httptest.Server, *auth.JWTService, *history.Store) {
	t.Helper()
	ctx := context.Background()
	conn, err := db.Open(ctx, ":memory:", testLogger())
	if err != nil {
		t.Fatalf("open memory db: %v", err)
	}
	t.Cleanup(func() { _ = conn.Close() })
	st, err := history.NewStore(ctx, conn, testLogger())
	if err != nil {
		t.Fatalf("new history store: %v", err)
	}
	srv, ts, jwt := buildEnv(t, cfgDefault(), Deps{History: st})
	return srv, ts, jwt, st
}

// decodeDataSlice decodes the {data:[...]} envelope into the given slice target.
func decodeDataSlice(t *testing.T, body []byte, out any) {
	t.Helper()
	if err := json.Unmarshal(decodeBody(t, body)["data"], out); err != nil {
		t.Fatalf("decode data: %v (body=%s)", err, body)
	}
}

func TestHistoryCreateAndListSessions(t *testing.T) {
	t.Parallel()
	_, ts, jwt, _ := newHistoryEnv(t)
	tok := signAny(t, jwt, "acct", auth.RoleOwner)

	// Fresh store always lists the main session.
	resp, body := doReq(t, http.MethodGet, ts.URL+"/api/v1/sessions", nil, tok)
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("list status = %d, want 200 (body=%s)", resp.StatusCode, body)
	}
	var initial []historySessionSummary
	decodeDataSlice(t, body, &initial)
	if len(initial) != 1 || initial[0].ID != history.MainSessionID || initial[0].Type != history.SessionMain {
		t.Fatalf("initial sessions = %+v, want [main web]", initial)
	}

	// Create a sub session.
	resp, body = doReq(t, http.MethodPost, ts.URL+"/api/v1/sessions", nil, tok)
	if resp.StatusCode != http.StatusCreated {
		t.Fatalf("create status = %d, want 201 (body=%s)", resp.StatusCode, body)
	}
	var created struct {
		SessionID string `json:"sessionId"`
	}
	if err := json.Unmarshal(decodeBody(t, body)["data"], &created); err != nil {
		t.Fatalf("decode create data: %v (body=%s)", err, body)
	}
	if !strings.HasPrefix(created.SessionID, history.MainSessionID+":") {
		t.Fatalf("sessionId = %q, want prefix web:", created.SessionID)
	}

	// Now main first, then the sub.
	resp, body = doReq(t, http.MethodGet, ts.URL+"/api/v1/sessions", nil, tok)
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("list status = %d, want 200 (body=%s)", resp.StatusCode, body)
	}
	var sessions []historySessionSummary
	decodeDataSlice(t, body, &sessions)
	if len(sessions) != 2 || sessions[0].ID != history.MainSessionID || sessions[0].Type != history.SessionMain {
		t.Fatalf("sessions[0] = %+v, want main web first", sessions[0])
	}
	if sessions[1].ID != created.SessionID || sessions[1].Type != history.SessionSub {
		t.Fatalf("sessions[1] = %+v, want sub %s", sessions[1], created.SessionID)
	}
}

func TestHistoryListMessagesPagination(t *testing.T) {
	t.Parallel()
	_, ts, jwt, st := newHistoryEnv(t)
	ctx := context.Background()
	// Seed the main session with messages at ascending ms timestamps.
	for _, ts := range []int64{1000, 2000, 3000, 4000} {
		if err := st.Append(ctx, history.Message{SessionID: history.MainSessionID, Role: history.RoleUser, Content: "x", CreatedAt: ts}); err != nil {
			t.Fatalf("seed %d: %v", ts, err)
		}
	}
	tok := signAny(t, jwt, "acct", auth.RoleOwner)

	// Newest page of 2.
	resp, body := doReq(t, http.MethodGet, ts.URL+"/api/v1/sessions/"+history.MainSessionID+"/messages?limit=2", nil, tok)
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("first page status = %d, want 200 (body=%s)", resp.StatusCode, body)
	}
	var page []historyMessage
	decodeDataSlice(t, body, &page)
	if len(page) != 2 || page[0].CreatedAt != 4000 || page[1].CreatedAt != 3000 {
		t.Fatalf("first page = %+v, want [4000 3000]", page)
	}

	// Cursor before the page's oldest (3000) → older page [2000 1000].
	resp, body = doReq(t, http.MethodGet, ts.URL+"/api/v1/sessions/"+history.MainSessionID+"/messages?before=3000&limit=2", nil, tok)
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("older page status = %d, want 200 (body=%s)", resp.StatusCode, body)
	}
	var older []historyMessage
	decodeDataSlice(t, body, &older)
	if len(older) != 2 || older[0].CreatedAt != 2000 || older[1].CreatedAt != 1000 {
		t.Fatalf("older page = %+v, want [2000 1000]", older)
	}

	// Invalid limit/before → 400.
	resp, body = doReq(t, http.MethodGet, ts.URL+"/api/v1/sessions/"+history.MainSessionID+"/messages?limit=abc", nil, tok)
	if resp.StatusCode != http.StatusBadRequest {
		t.Fatalf("invalid limit status = %d, want 400 (body=%s)", resp.StatusCode, body)
	}
}

func TestHistoryListMessagesPlatformFilter(t *testing.T) {
	t.Parallel()
	_, ts, jwt, st := newHistoryEnv(t)
	ctx := context.Background()
	if err := st.Append(ctx, history.Message{SessionID: history.MainSessionID, Role: history.RoleUser, Content: "web", Platform: history.PlatformWeb, CreatedAt: 1000}); err != nil {
		t.Fatalf("seed web: %v", err)
	}
	if err := st.Append(ctx, history.Message{SessionID: history.MainSessionID, Role: history.RoleUser, Content: "tg", Platform: "telegram", CreatedAt: 2000}); err != nil {
		t.Fatalf("seed tg: %v", err)
	}
	tok := signAny(t, jwt, "acct", auth.RoleOwner)

	// No platform → the full main session (both lanes).
	resp, body := doReq(t, http.MethodGet, ts.URL+"/api/v1/sessions/"+history.MainSessionID+"/messages?limit=10", nil, tok)
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("all status = %d, want 200 (body=%s)", resp.StatusCode, body)
	}
	var all []historyMessage
	decodeDataSlice(t, body, &all)
	if len(all) != 2 {
		t.Fatalf("all = %d, want 2", len(all))
	}

	// ?platform=telegram → only the telegram lane, and the DTO carries platform.
	resp, body = doReq(t, http.MethodGet, ts.URL+"/api/v1/sessions/"+history.MainSessionID+"/messages?limit=10&platform=telegram", nil, tok)
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("platform status = %d, want 200 (body=%s)", resp.StatusCode, body)
	}
	var tg []historyMessage
	decodeDataSlice(t, body, &tg)
	if len(tg) != 1 || tg[0].Content != "tg" || tg[0].Platform != "telegram" {
		t.Fatalf("telegram page = %+v, want one platform=telegram message", tg)
	}
}

func TestHistoryDeleteSubSession(t *testing.T) {
	t.Parallel()
	_, ts, jwt, st := newHistoryEnv(t)
	ctx := context.Background()
	tok := signAny(t, jwt, "acct", auth.RoleOwner)

	// Create a sub and seed a message.
	resp, body := doReq(t, http.MethodPost, ts.URL+"/api/v1/sessions", nil, tok)
	if resp.StatusCode != http.StatusCreated {
		t.Fatalf("create status = %d, want 201 (body=%s)", resp.StatusCode, body)
	}
	var created struct {
		SessionID string `json:"sessionId"`
	}
	if err := json.Unmarshal(decodeBody(t, body)["data"], &created); err != nil {
		t.Fatalf("decode create data: %v", err)
	}
	if err := st.Append(ctx, history.Message{SessionID: created.SessionID, Role: history.RoleUser, Content: "x", CreatedAt: 1000}); err != nil {
		t.Fatalf("seed sub: %v", err)
	}

	// Delete it.
	resp, _ = doReq(t, http.MethodDelete, ts.URL+"/api/v1/sessions/"+created.SessionID, nil, tok)
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("delete status = %d, want 200", resp.StatusCode)
	}
	// It is gone from the list.
	resp, body = doReq(t, http.MethodGet, ts.URL+"/api/v1/sessions", nil, tok)
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("list status = %d, want 200", resp.StatusCode)
	}
	var sessions []historySessionSummary
	decodeDataSlice(t, body, &sessions)
	if len(sessions) != 1 || sessions[0].ID != history.MainSessionID {
		t.Fatalf("sessions after delete = %+v, want [main]", sessions)
	}

	// Main session is immutable → 403.
	resp, body = doReq(t, http.MethodDelete, ts.URL+"/api/v1/sessions/"+history.MainSessionID, nil, tok)
	if resp.StatusCode != http.StatusForbidden {
		t.Fatalf("delete main status = %d, want 403 (body=%s)", resp.StatusCode, body)
	}
	wantErrorShape(t, body)
}

func TestHistoryNotWired(t *testing.T) {
	t.Parallel()
	_, ts, jwt := buildEnv(t, cfgDefault(), Deps{})
	tok := signAny(t, jwt, "acct", auth.RoleOwner)

	// Messages/create/delete answer a clear 501 when no history store is wired.
	for _, tc := range []struct {
		method, url string
		want        int
	}{
		{http.MethodGet, "/api/v1/sessions/web/messages?limit=2", http.StatusNotImplemented},
		{http.MethodPost, "/api/v1/sessions", http.StatusNotImplemented},
	} {
		resp, body := doReq(t, tc.method, ts.URL+tc.url, nil, tok)
		if resp.StatusCode != tc.want {
			t.Fatalf("%s %s status = %d, want %d (body=%s)", tc.method, tc.url, resp.StatusCode, tc.want, body)
		}
		if !strings.Contains(string(body), "not_implemented") {
			t.Fatalf("%s %s body = %s, want not_implemented code", tc.method, tc.url, body)
		}
	}
}

func TestHistoryRBAC(t *testing.T) {
	t.Parallel()
	_, ts, jwt, _ := newHistoryEnv(t)
	viewer := signAny(t, jwt, "acct", auth.RoleViewer)
	owner := signAny(t, jwt, "acct", auth.RoleOwner)

	// Viewer can list session metadata (readAuth) but not read/write history content.
	resp, _ := doReq(t, http.MethodGet, ts.URL+"/api/v1/sessions", nil, viewer)
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("viewer list sessions status = %d, want 200", resp.StatusCode)
	}
	resp, body := doReq(t, http.MethodGet, ts.URL+"/api/v1/sessions/web/messages", nil, viewer)
	if resp.StatusCode != http.StatusForbidden {
		t.Fatalf("viewer messages status = %d, want 403 (body=%s)", resp.StatusCode, body)
	}
	resp, body = doReq(t, http.MethodPost, ts.URL+"/api/v1/sessions", nil, viewer)
	if resp.StatusCode != http.StatusForbidden {
		t.Fatalf("viewer create status = %d, want 403 (body=%s)", resp.StatusCode, body)
	}
	// Owner can read messages.
	resp, _ = doReq(t, http.MethodGet, ts.URL+"/api/v1/sessions/web/messages?limit=2", nil, owner)
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("owner messages status = %d, want 200", resp.StatusCode)
	}
}