package domain

import (
	"fmt"
	"reflect"
	"testing"
)

func TestExchangeHistoryOwnershipAndBranches(t *testing.T) {
	control := &CacheControl{Type: CacheControlEphemeral, TTL: "1h"}
	source := []RenderedMessage{{Role: RoleSystem, Content: "", CacheControl: control}, {Role: RoleUser, Content: "question"}}
	initial := CaptureExchange(nil, "first", source, " answer ")
	first := CaptureExchange(initial, "second", []RenderedMessage{{Role: RoleUser, Content: "follow-up"}}, "reply")
	second := CaptureExchange(initial, "third", []RenderedMessage{{Role: RoleDeveloper, Content: "other"}}, "")
	source[0].Content = "changed"
	control.TTL = "changed"
	got := initial.Messages()
	want := []RenderedMessage{{Role: RoleSystem, Content: "", CacheControl: &CacheControl{Type: CacheControlEphemeral, TTL: "1h"}}, {Role: RoleUser, Content: "question"}, {Role: RoleAssistant, Content: " answer "}}
	if !reflect.DeepEqual(got, want) {
		t.Fatalf("initial messages = %#v, want %#v", got, want)
	}
	got[0].CacheControl.TTL = "mutated"
	got[1].Content = "mutated"
	if !reflect.DeepEqual(initial.Messages(), want) {
		t.Fatal("returned messages changed retained history")
	}
	if first.RunID() != "second" || first.ParentRunID() != "first" || first.MessageCount() != 5 {
		t.Fatal("incorrect branch metadata")
	}
	if second.ParentRunID() != "first" || second.Messages()[3].Content != "other" || second.Messages()[4].Content != "" {
		t.Fatal("incorrect sibling history")
	}
	if first.Messages()[3].Content != "follow-up" || !reflect.DeepEqual(initial.Messages(), want) {
		t.Fatal("branches changed each other or their parent")
	}
}

func TestExchangeManyTurns(t *testing.T) {
	var exchange *Exchange
	const turns = 2000
	for i := 0; i < turns; i++ {
		exchange = CaptureExchange(exchange, fmt.Sprint(i), []RenderedMessage{{Role: RoleUser, Content: fmt.Sprint(i)}}, fmt.Sprint(i))
	}
	messages := exchange.Messages()
	if len(messages) != turns*2 || exchange.MessageCount() != len(messages) {
		t.Fatalf("unexpected history length: %d", len(messages))
	}
	for i := 0; i < turns; i++ {
		if messages[2*i].Content != fmt.Sprint(i) || messages[2*i+1].Role != RoleAssistant || messages[2*i+1].Content != fmt.Sprint(i) {
			t.Fatalf("unexpected turn %d: %#v", i, messages[2*i:2*i+2])
		}
	}
}

func TestExchangeMessagesWithSuffix(t *testing.T) {
	for _, history := range []*Exchange{nil, CaptureExchange(nil, "source", nil, "answer")} {
		control := &CacheControl{Type: CacheControlEphemeral, TTL: "1h"}
		first := []RenderedMessage{{Role: RoleUser, Content: "new", CacheControl: control}}
		last := []RenderedMessage{{Role: RoleDeveloper, Content: "suffix"}}
		got := history.MessagesWithSuffix(first, nil, last)
		want := append(history.Messages(), first...)
		want = append(want, last...)
		if !reflect.DeepEqual(got, want) {
			t.Fatalf("messages = %#v, want %#v", got, want)
		}
		got[history.MessageCount()].CacheControl.TTL = "changed"
		got[history.MessageCount()].Content = "changed"
		if first[0].Content != "new" || control.TTL != "1h" {
			t.Fatal("assembled messages alias the caller suffix")
		}
		if history != nil && history.Messages()[0].Content != "answer" {
			t.Fatal("assembly changed retained history")
		}
	}
}