package server

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

	"github.com/coder/websocket"

	"github.com/greyson/super-auto-pets-board-game/internal/game"
	"github.com/greyson/super-auto-pets-board-game/internal/store"
)

// TestE2EBotGame creates a vs-computer game over the API, plays the human's
// shop turns over the wire, and verifies the scheduled bot actually takes
// its own turns (spends coins) without any second client connected.
func TestE2EBotGame(t *testing.T) {
	st, err := store.Open(t.TempDir())
	if err != nil {
		t.Fatal(err)
	}
	defer st.Close()
	srv := New(st, "", false)
	ts := httptest.NewServer(srv.Handler())
	defer ts.Close()

	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
	defer cancel()

	resp, err := http.Post(ts.URL+"/api/games", "application/json",
		bytes.NewBufferString(`{"name":"Human"}`))
	if err != nil {
		t.Fatal(err)
	}
	var join joinResponse
	if err := json.NewDecoder(resp.Body).Decode(&join); err != nil {
		t.Fatal(err)
	}
	resp.Body.Close()

	wsBase := "ws" + strings.TrimPrefix(ts.URL, "http")
	ws, _, err := websocket.Dial(ctx,
		wsBase+"/api/ws?game="+join.GameID+"&player="+join.PlayerID+"&token="+join.Token, nil)
	if err != nil {
		t.Fatal(err)
	}
	defer ws.Close(websocket.StatusNormalClosure, "")

	// The host opens in the lobby, adds a bot, then starts the game — the
	// unified lobby flow a real client drives.
	if p := readState(t, ctx, ws).Phase; p != game.PhaseLobby {
		t.Fatalf("phase = %s, want lobby on create", p)
	}
	send(t, ctx, ws, map[string]any{"type": "addBot", "difficulty": "easy"})
	send(t, ctx, ws, map[string]any{"type": "start"})

	var v *game.View
	startDeadline := time.Now().Add(5 * time.Second)
	for (v == nil || v.Phase != game.PhaseShop) && time.Now().Before(startDeadline) {
		rctx, rcancel := context.WithTimeout(ctx, 3*time.Second)
		v = readState(t, rctx, ws)
		rcancel()
	}
	if v.Phase != game.PhaseShop {
		t.Fatalf("phase = %s, want shop after host starts", v.Phase)
	}
	var bot *game.PlayerView
	for i := range v.Players {
		if v.Players[i].IsBot {
			bot = &v.Players[i]
		}
	}
	if bot == nil {
		t.Fatal("no bot seat in the game")
	}

	// Play the human side: pass on our first turn (passing is final, so one
	// is all we get). The game can only reach the arrange phase if the bot
	// shops and passes on its own too.
	deadline := time.Now().Add(25 * time.Second)
	for v.Phase == game.PhaseShop && time.Now().Before(deadline) {
		if v.Turn == v.YouSeat && !v.Players[v.YouSeat].Ready && v.Pending == nil {
			send(t, ctx, ws, map[string]any{"type": "pass"})
		}
		rctx, rcancel := context.WithTimeout(ctx, 10*time.Second)
		v = readState(t, rctx, ws)
		rcancel()
	}
	if v.Phase == game.PhaseShop {
		t.Fatalf("shop never ended; bot coins=%d", v.Players[bot.Seat].Coins)
	}
	t.Logf("reached phase %s; bot played its shop turns", v.Phase)
}

// TestE2EFourPlayerBotGame runs a four-seat game (one human, three bots) over
// the API and plays a full round. It's the multiplayer counterpart to
// TestE2EBotGame: the bot driver has to keep three seats moving through a
// shop that takes turns four ways, and the round has to resolve two battles at
// once rather than one.
func TestE2EFourPlayerBotGame(t *testing.T) {
	st, err := store.Open(t.TempDir())
	if err != nil {
		t.Fatal(err)
	}
	defer st.Close()
	srv := New(st, "", false)
	ts := httptest.NewServer(srv.Handler())
	defer ts.Close()

	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Minute)
	defer cancel()

	resp, err := http.Post(ts.URL+"/api/games", "application/json",
		bytes.NewBufferString(`{"name":"Human"}`))
	if err != nil {
		t.Fatal(err)
	}
	var join joinResponse
	if err := json.NewDecoder(resp.Body).Decode(&join); err != nil {
		t.Fatal(err)
	}
	resp.Body.Close()

	wsBase := "ws" + strings.TrimPrefix(ts.URL, "http")
	ws, _, err := websocket.Dial(ctx,
		wsBase+"/api/ws?game="+join.GameID+"&player="+join.PlayerID+"&token="+join.Token, nil)
	if err != nil {
		t.Fatal(err)
	}
	defer ws.Close(websocket.StatusNormalClosure, "")

	if p := readState(t, ctx, ws).Phase; p != game.PhaseLobby {
		t.Fatalf("phase = %s, want lobby on create", p)
	}
	// Four seats need two packs shuffled together, per the rulebook.
	send(t, ctx, ws, map[string]any{"type": "setPacks", "packs": []string{"turtle", "golden"}})
	for _, level := range []string{"easy", "medium", "hard"} {
		send(t, ctx, ws, map[string]any{"type": "addBot", "difficulty": level})
	}
	send(t, ctx, ws, map[string]any{"type": "start"})

	var v *game.View
	deadline := time.Now().Add(2 * time.Minute)
	for time.Now().Before(deadline) {
		rctx, rcancel := context.WithTimeout(ctx, 20*time.Second)
		v = readState(t, rctx, ws)
		rcancel()
		if v.Phase == game.PhaseLobby {
			continue
		}
		if len(v.Players) != 4 {
			t.Fatalf("expected 4 seats, got %d", len(v.Players))
		}
		// Play the human side: pass as soon as it's our turn, then submit our
		// deck as-is. The round can only progress if the three bots take their
		// own turns around us.
		switch v.Phase {
		case game.PhaseShop:
			if v.Turn == v.YouSeat && !v.Players[v.YouSeat].Ready && v.Pending == nil &&
				v.PendingReveal == nil && v.PendingSacrifice == nil {
				send(t, ctx, ws, map[string]any{"type": "pass"})
			}
		case game.PhaseArrange:
			if !v.Players[v.YouSeat].Ready {
				ids := []string{}
				for _, c := range v.Players[v.YouSeat].Deck {
					ids = append(ids, c.ID)
				}
				send(t, ctx, ws, map[string]any{"type": "arrange", "order": ids})
			}
		case game.PhaseBattle:
			goto resolved
		}
	}
	t.Fatalf("never reached the battle phase; stuck in %s", v.Phase)

resolved:
	// Every bot name should be distinct, or the table is unreadable.
	names := map[string]bool{}
	for _, p := range v.Players {
		if names[p.Name] {
			t.Errorf("two seats are both called %q", p.Name)
		}
		names[p.Name] = true
	}
	// Four players pair into two simultaneous battles, together seating everyone.
	if len(v.Battles) != 2 {
		t.Fatalf("round resolved %d battles, want 2", len(v.Battles))
	}
	fought := map[int]bool{}
	for _, b := range v.Battles {
		for _, seat := range b.Seats {
			fought[seat] = true
		}
	}
	if len(fought) != 4 {
		t.Errorf("%d of 4 seats fought this round", len(fought))
	}
	if v.Battle == nil || !v.Battle.Has(v.YouSeat) {
		t.Error("the view should single out the battle the human fought")
	}
	t.Logf("four-player round resolved: %d battles, seats %v", len(v.Battles), fought)
}