package channel

import (
	"net/http"
	"net/http/httptest"
	"testing"

	relaycommon "github.com/QuantumNous/new-api/relay/common"
	"github.com/gin-gonic/gin"
	"github.com/stretchr/testify/require"
)

func TestProcessHeaderOverride_ChannelTestSkipsPassthroughRules(t *testing.T) {
	t.Parallel()

	gin.SetMode(gin.TestMode)
	recorder := httptest.NewRecorder()
	ctx, _ := gin.CreateTestContext(recorder)
	ctx.Request = httptest.NewRequest(http.MethodPost, "/v1/chat/completions", nil)
	ctx.Request.Header.Set("X-Trace-Id", "trace-123")

	info := &relaycommon.RelayInfo{
		IsChannelTest: true,
		ChannelMeta: &relaycommon.ChannelMeta{
			HeadersOverride: map[string]any{
				"*": "",
			},
		},
	}

	headers, err := processHeaderOverride(info, ctx)
	require.NoError(t, err)
	require.Empty(t, headers)
}

func TestProcessHeaderOverride_ChannelTestSkipsClientHeaderPlaceholder(t *testing.T) {
	t.Parallel()

	gin.SetMode(gin.TestMode)
	recorder := httptest.NewRecorder()
	ctx, _ := gin.CreateTestContext(recorder)
	ctx.Request = httptest.NewRequest(http.MethodPost, "/v1/chat/completions", nil)
	ctx.Request.Header.Set("X-Trace-Id", "trace-123")

	info := &relaycommon.RelayInfo{
		IsChannelTest: true,
		ChannelMeta: &relaycommon.ChannelMeta{
			HeadersOverride: map[string]any{
				"X-Upstream-Trace": "{client_header:X-Trace-Id}",
			},
		},
	}

	headers, err := processHeaderOverride(info, ctx)
	require.NoError(t, err)
	_, ok := headers["X-Upstream-Trace"]
	require.False(t, ok)
}

func TestProcessHeaderOverride_NonTestKeepsClientHeaderPlaceholder(t *testing.T) {
	t.Parallel()

	gin.SetMode(gin.TestMode)
	recorder := httptest.NewRecorder()
	ctx, _ := gin.CreateTestContext(recorder)
	ctx.Request = httptest.NewRequest(http.MethodPost, "/v1/chat/completions", nil)
	ctx.Request.Header.Set("X-Trace-Id", "trace-123")

	info := &relaycommon.RelayInfo{
		IsChannelTest: false,
		ChannelMeta: &relaycommon.ChannelMeta{
			HeadersOverride: map[string]any{
				"X-Upstream-Trace": "{client_header:X-Trace-Id}",
			},
		},
	}

	headers, err := processHeaderOverride(info, ctx)
	require.NoError(t, err)
	require.Equal(t, "trace-123", headers["X-Upstream-Trace"])
}

func TestProcessHeaderOverride_RuntimeOverrideMergesWithChannelOverride(t *testing.T) {
	t.Parallel()

	gin.SetMode(gin.TestMode)
	recorder := httptest.NewRecorder()
	ctx, _ := gin.CreateTestContext(recorder)
	ctx.Request = httptest.NewRequest(http.MethodPost, "/v1/chat/completions", nil)

	info := &relaycommon.RelayInfo{
		IsChannelTest:             false,
		UseRuntimeHeadersOverride: true,
		RuntimeHeadersOverride: map[string]any{
			"X-Static":  "runtime-value",
			"X-Runtime": "runtime-only",
		},
		ChannelMeta: &relaycommon.ChannelMeta{
			HeadersOverride: map[string]any{
				"X-Static": "legacy-value",
				"X-Legacy": "legacy-only",
			},
		},
	}

	headers, err := processHeaderOverride(info, ctx)
	require.NoError(t, err)
	require.Equal(t, "runtime-value", headers["X-Static"])
	require.Equal(t, "runtime-only", headers["X-Runtime"])
	require.Equal(t, "legacy-only", headers["X-Legacy"])
}

func TestProcessHeaderOverride_PassthroughSkipsAcceptEncoding(t *testing.T) {
	t.Parallel()

	gin.SetMode(gin.TestMode)
	recorder := httptest.NewRecorder()
	ctx, _ := gin.CreateTestContext(recorder)
	ctx.Request = httptest.NewRequest(http.MethodPost, "/v1/chat/completions", nil)
	ctx.Request.Header.Set("X-Trace-Id", "trace-123")
	ctx.Request.Header.Set("Accept-Encoding", "gzip")

	info := &relaycommon.RelayInfo{
		IsChannelTest: false,
		ChannelMeta: &relaycommon.ChannelMeta{
			HeadersOverride: map[string]any{
				"*": "",
			},
		},
	}

	headers, err := processHeaderOverride(info, ctx)
	require.NoError(t, err)
	require.Equal(t, "trace-123", headers["X-Trace-Id"])

	_, hasAcceptEncoding := headers["Accept-Encoding"]
	require.False(t, hasAcceptEncoding)
}

func TestProcessHeaderOverride_PassHeadersTemplateSetsRuntimeHeaders(t *testing.T) {
	t.Parallel()

	gin.SetMode(gin.TestMode)
	recorder := httptest.NewRecorder()
	ctx, _ := gin.CreateTestContext(recorder)
	ctx.Request = httptest.NewRequest(http.MethodPost, "/v1/responses", nil)
	ctx.Request.Header.Set("Originator", "Codex CLI")
	ctx.Request.Header.Set("Session_id", "sess-123")

	info := &relaycommon.RelayInfo{
		IsChannelTest: false,
		RequestHeaders: map[string]string{
			"Originator": "Codex CLI",
			"Session_id": "sess-123",
		},
		ChannelMeta: &relaycommon.ChannelMeta{
			ParamOverride: map[string]any{
				"operations": []any{
					map[string]any{
						"mode":  "pass_headers",
						"value": []any{"Originator", "Session_id", "X-Codex-Beta-Features"},
					},
				},
			},
			HeadersOverride: map[string]any{
				"X-Static": "legacy-value",
			},
		},
	}

	_, err := relaycommon.ApplyParamOverrideWithRelayInfo([]byte(`{"model":"gpt-4.1"}`), info)
	require.NoError(t, err)
	require.True(t, info.UseRuntimeHeadersOverride)
	require.Equal(t, "Codex CLI", info.RuntimeHeadersOverride["Originator"])
	require.Equal(t, "sess-123", info.RuntimeHeadersOverride["Session_id"])
	_, exists := info.RuntimeHeadersOverride["X-Codex-Beta-Features"]
	require.False(t, exists)

	headers, err := processHeaderOverride(info, ctx)
	require.NoError(t, err)
	require.Equal(t, "Codex CLI", headers["Originator"])
	require.Equal(t, "sess-123", headers["Session_id"])
	_, exists = headers["X-Codex-Beta-Features"]
	require.False(t, exists)

	upstreamReq := httptest.NewRequest(http.MethodPost, "https://example.com/v1/responses", nil)
	applyHeaderOverrideToRequest(upstreamReq, headers)
	require.Equal(t, "Codex CLI", upstreamReq.Header.Get("Originator"))
	require.Equal(t, "sess-123", upstreamReq.Header.Get("Session_id"))
	require.Empty(t, upstreamReq.Header.Get("X-Codex-Beta-Features"))
}