package lua

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"os"
	"os/exec"
	"strings"
	"testing"
	"time"
)

// 真上游 e2e：用适配器产出的头 + body 直打 opencode /inference/v1。
// 需要真实凭据（从生产配置解密），故用 MODELROUTER_LIVE_ZEN=1 显式开启。
func TestOpencodeZenLiveE2E(t *testing.T) {
	if os.Getenv("MODELROUTER_LIVE_ZEN") != "1" {
		t.Skip("设 MODELROUTER_LIVE_ZEN=1 开启真上游 e2e")
	}
	src, err := bundledAdapters.ReadFile("adapters/opencodezen.lua")
	if err != nil {
		t.Fatal(err)
	}
	vm := NewVM(t.TempDir())
	defer vm.Stop()
	if err := vm.LoadAdapterSource("opencodezen", string(src)); err != nil {
		t.Fatal(err)
	}

	// 取生产凭据（解密）
	out, err := exec.Command(gatewayBinary(), "-show-secrets",
		"-config", "/etc/modelrouter/config.yaml").Output()
	if err != nil {
		t.Fatal(err)
	}
	apiKey := ""
	for _, l := range strings.Split(string(out), "\n") {
		if strings.HasPrefix(l, "source localzen") {
			if i := strings.Index(l, "api_key="); i >= 0 {
				apiKey = strings.TrimSpace(l[i+len("api_key="):])
			}
		}
	}
	if apiKey == "" {
		t.Fatal("未取到 localzen 凭据")
	}

	cases := []struct {
		name string
		body string
		want string
	}{
		{"纯对话（无 tools，靠适配器兜底注入）",
			`{"model":"deepseek-v4.1-flash-free","stream":true,"max_tokens":60,
			  "messages":[{"role":"user","content":"reply with exactly: ADAPTER-OK"}]}`, "ADAPTER-OK"},
		{"带自定义 system",
			`{"model":"deepseek-v4.1-flash-free","stream":true,"max_tokens":60,
			  "messages":[{"role":"system","content":"You are terse."},{"role":"user","content":"reply with exactly: SYS-OK"}]}`, "SYS-OK"},
		{"多轮",
			`{"model":"deepseek-v4.1-flash-free","stream":true,"max_tokens":60,
			  "messages":[{"role":"user","content":"a"},{"role":"assistant","content":"b"},{"role":"user","content":"reply with exactly: MULTI-OK"}]}`, "MULTI-OK"},
		{"算术（验证真推理）",
			`{"model":"deepseek-v4.1-flash-free","stream":true,"max_tokens":60,
			  "messages":[{"role":"user","content":"What is 17*23? Reply with just the number."}]}`, "391"},
	}

	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			body, err := vm.Transform("opencodezen", "transform_request", tc.body)
			if err != nil {
				t.Fatal(err)
			}
			h, err := vm.BuildHeaders("opencodezen", map[string]interface{}{
				"timestamp": time.Now().Unix(), "body": body,
			})
			if err != nil {
				t.Fatal(err)
			}
			req, _ := http.NewRequest("POST",
				"https://opencode.ai/inference/v1/chat/completions", bytes.NewReader([]byte(body)))
			for k, v := range h {
				req.Header.Set(k, v)
			}
			req.Header.Set("Content-Type", "application/json")
			req.Header.Set("Authorization", "Bearer "+apiKey)
			cl := &http.Client{Timeout: 90 * time.Second}
			resp, err := cl.Do(req)
			if err != nil {
				t.Fatal(err)
			}
			raw, _ := io.ReadAll(resp.Body)
			resp.Body.Close()
			if resp.StatusCode != 200 {
				t.Fatalf("HTTP %d: %s", resp.StatusCode, string(raw)[:min(300, len(raw))])
			}
			// 上游现在返回 SSE（适配器强制 stream=true）；判据需自己拼 delta.content。
			got := ""
			for _, line := range strings.Split(string(raw), "\n") {
				line = strings.TrimSpace(line)
				if !strings.HasPrefix(line, "data: ") {
					continue
				}
				p := strings.TrimPrefix(line, "data: ")
				if p == "[DONE]" {
					continue
				}
				var d struct {
					Choices []struct {
						Delta struct{ Content string } `json:"delta"`
					} `json:"choices"`
				}
				if json.Unmarshal([]byte(p), &d) != nil || len(d.Choices) == 0 {
					continue
				}
				got += d.Choices[0].Delta.Content
			}
			if got == "" {
				t.Fatalf("未从 SSE 解出内容；原始=%s", string(raw)[:min(300, len(raw))])
			}
			if !strings.Contains(got, tc.want) {
				t.Fatalf("回复 %q 不含 %q", got, tc.want)
			}
			t.Logf("✓ %s → %q", tc.name, strings.TrimSpace(got))
		})
	}
	fmt.Println("真上游 e2e 全部通过")
}

// 经适配器完整转换链：上游 SSE → transform_stream_chunk → 统一格式。
// 上一条判据直接读原始 SSE，只证明"上游放行"；这条证明"适配器能解析"。
func TestOpencodeZenLiveStreamThroughAdapter(t *testing.T) {
	if os.Getenv("MODELROUTER_LIVE_ZEN") != "1" {
		t.Skip("设 MODELROUTER_LIVE_ZEN=1 开启")
	}
	src, err := bundledAdapters.ReadFile("adapters/opencodezen.lua")
	if err != nil {
		t.Fatal(err)
	}
	vm := NewVM(t.TempDir())
	defer vm.Stop()
	if err := vm.LoadAdapterSource("opencodezen", string(src)); err != nil {
		t.Fatal(err)
	}
	out, _ := exec.Command(gatewayBinary(), "-show-secrets",
		"-config", "/etc/modelrouter/config.yaml").Output()
	apiKey := ""
	for _, l := range strings.Split(string(out), "\n") {
		if strings.HasPrefix(l, "source localzen") {
			if i := strings.Index(l, "api_key="); i >= 0 {
				apiKey = strings.TrimSpace(l[i+len("api_key="):])
			}
		}
	}

	body, _ := vm.Transform("opencodezen", "transform_request",
		`{"model":"deepseek-v4.1-flash-free","stream":true,"max_tokens":60,
		  "messages":[{"role":"user","content":"reply with exactly: CHAIN-OK"}]}`)
	h, _ := vm.BuildHeaders("opencodezen", map[string]interface{}{
		"timestamp": time.Now().Unix(), "body": body})

	req, _ := http.NewRequest("POST",
		"https://opencode.ai/inference/v1/chat/completions", bytes.NewReader([]byte(body)))
	for k, v := range h {
		req.Header.Set(k, v)
	}
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Authorization", "Bearer "+apiKey)
	resp, err := (&http.Client{Timeout: 90 * time.Second}).Do(req)
	if err != nil {
		t.Fatal(err)
	}
	raw, _ := io.ReadAll(resp.Body)
	resp.Body.Close()
	if resp.StatusCode != 200 {
		t.Fatalf("HTTP %d: %s", resp.StatusCode, string(raw)[:min(300, len(raw))])
	}

	// 逐行喂给适配器的流解析器，累积统一格式的 content
	joined := ""
	n := 0
	for _, line := range strings.Split(string(raw), "\n") {
		line = strings.TrimSpace(line)
		if !strings.HasPrefix(line, "data: ") || line == "data: [DONE]" {
			continue
		}
		// 内核喂给适配器的是**已剥掉 data: 前缀**的载荷（见 provider.go：
		// strings.TrimPrefix(line, "data:")），判据必须对齐这个契约。
		payload := strings.TrimSpace(strings.TrimPrefix(line, "data:"))
		unified, err := vm.Transform("opencodezen", "transform_stream_chunk", payload)
		if err != nil {
			t.Fatalf("transform_stream_chunk: %v (%s)", err, line[:min(120, len(line))])
		}
		if unified == "" || unified == "{}" {
			continue
		}
		var u struct {
			Content string `json:"content"`
		}
		if json.Unmarshal([]byte(unified), &u) == nil {
			joined += u.Content
			n++
		}
	}
	if n == 0 {
		t.Fatal("适配器未解出任何 chunk（流解析链断了）")
	}
	if !strings.Contains(joined, "CHAIN-OK") {
		t.Fatalf("经适配器链的内容 %q 不含 CHAIN-OK（chunk 数=%d）", joined, n)
	}
	t.Logf("✓ 完整链：%d 个 chunk，内容=%q", n, strings.TrimSpace(joined))
}

// gatewayBinary 定位本机网关二进制。改名后默认是 /usr/local/bin/modelrouter；
// 仍兼容改名前的 /usr/local/bin/llmsproxy，避免测试脚本要跟着运维机器改。
func gatewayBinary() string {
	if v := os.Getenv("MODELROUTER_BIN"); v != "" {
		return v
	}
	for _, p := range []string{"/usr/local/bin/modelrouter", "/usr/local/bin/llmsproxy"} {
		if _, err := os.Stat(p); err == nil {
			return p
		}
	}
	return "/usr/local/bin/modelrouter"
}