package agent_test

import (
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"

	"chat-agent-system/internal/agent"
	"chat-agent-system/internal/config"
)

func TestStubBackendExecution(t *testing.T) {
	tmpDir := t.TempDir()
	cfg := &config.Config{AgentBackend: "stub"}

	backend := agent.NewBackend("stub", cfg)
	if backend.Name() != "stub" {
		t.Errorf("expected stub backend, got %s", backend.Name())
	}

	req := agent.Request{
		WorkDir: tmpDir,
		Prompt:  "请编写用户初始需求收集表",
		Targets: []string{"output.md"},
		Timeout: 5 * time.Second,
	}

	res, err := backend.Execute(context.Background(), req)
	if err != nil {
		t.Fatalf("stub execute failed: %v", err)
	}
	if !res.Success {
		t.Fatalf("expected success")
	}

	outputPath := filepath.Join(tmpDir, "output.md")
	if _, err := os.Stat(outputPath); err != nil {
		t.Fatalf("expected output.md to exist: %v", err)
	}
}

func TestPiAgentRemoteRunner(t *testing.T) {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/v1/run" {
			http.NotFound(w, r)
			return
		}
		var payload map[string]any
		_ = json.NewDecoder(r.Body).Decode(&payload)

		resp := map[string]any{
			"ok": true,
			"patches": []map[string]string{
				{
					"rel_path": "output.md",
					"content":  "# Remote Generated Deliverable\nValidated from Container Runner",
				},
			},
		}
		w.Header().Set("Content-Type", "application/json")
		_ = json.NewEncoder(w).Encode(resp)
	}))
	defer ts.Close()

	tmpDir := t.TempDir()
	cfg := &config.Config{
		AgentBackend:     "pi-agent",
		PiAgentRunnerURL: ts.URL,
		PiAgentModel:     "MiniMax-M3",
		PiAgentProvider:  "minimax",
		AgentTimeout:     5 * time.Second,
	}

	backend := agent.NewBackend("pi-agent", cfg)
	res, err := backend.Execute(context.Background(), agent.Request{
		WorkDir: tmpDir,
		Prompt:  "Generate remote test document",
		Targets: []string{"output.md"},
	})
	if err != nil {
		t.Fatalf("remote execute returned unexpected error: %v", err)
	}
	if !res.Success {
		t.Fatalf("expected success, got error: %s", res.ErrorReason)
	}
	if string(res.Patches["output.md"]) != "# Remote Generated Deliverable\nValidated from Container Runner" {
		t.Errorf("unexpected content: %s", string(res.Patches["output.md"]))
	}

	// Verify local file written
	localContent, err := os.ReadFile(filepath.Join(tmpDir, "output.md"))
	if err != nil {
		t.Fatalf("expected local file written: %v", err)
	}
	if string(localContent) != "# Remote Generated Deliverable\nValidated from Container Runner" {
		t.Errorf("unexpected local file content: %s", string(localContent))
	}
}

func TestPiAgentRemoteRunner_PathAliasesAndMissing(t *testing.T) {
	run := func(mode, want string, expectOK bool) {
		t.Helper()
		dir := filepath.Join(t.TempDir(), "tasks", "01_draft")
		if err := os.MkdirAll(dir, 0o755); err != nil {
			t.Fatal(err)
		}
		ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			if r.URL.Path != "/v1/run" {
				http.NotFound(w, r)
				return
			}
			var patches []map[string]string
			switch mode {
			case "abs":
				patches = []map[string]string{{
					"rel_path": filepath.Join(dir, "output.md"),
					"content":  "# from absolute rel_path\n",
				}}
			case "nested":
				patches = []map[string]string{{
					"rel_path": "tasks/01_draft/output.md",
					"content":  "# from nested rel_path\n",
				}}
			case "dot":
				patches = []map[string]string{{
					"rel_path": "./output.md",
					"content":  "# from dot rel_path\n",
				}}
			default:
				patches = []map[string]string{{
					"rel_path": "execution.log",
					"content":  "Outcome: SUCCESS\n",
				}}
			}
			_ = json.NewEncoder(w).Encode(map[string]any{"ok": true, "patches": patches})
		}))
		defer ts.Close()

		cfg := &config.Config{
			AgentBackend:     "pi-agent",
			PiAgentRunnerURL: ts.URL,
			PiAgentModel:     "MiniMax-M3",
			PiAgentProvider:  "minimax",
			AgentTimeout:     5 * time.Second,
		}
		res, err := agent.NewBackend("pi-agent", cfg).Execute(context.Background(), agent.Request{
			WorkDir: dir,
			Prompt:  "draft",
			Targets: []string{"output.md"},
		})
		if err != nil {
			t.Fatalf("mode %s unexpected err: %v", mode, err)
		}
		if expectOK {
			if !res.Success {
				t.Fatalf("mode %s want success, got %s", mode, res.ErrorReason)
			}
			got, rerr := os.ReadFile(filepath.Join(dir, "output.md"))
			if rerr != nil {
				t.Fatalf("mode %s missing file: %v", mode, rerr)
			}
			if string(got) != want {
				t.Fatalf("mode %s content %q", mode, got)
			}
			return
		}
		if res.Success {
			t.Fatalf("mode %s must fail closed", mode)
		}
		if !strings.Contains(res.ErrorReason, "missing target deliverable output.md") {
			t.Fatalf("mode %s reason %q", mode, res.ErrorReason)
		}
		if _, serr := os.Stat(filepath.Join(dir, "output.md")); serr == nil {
			t.Fatalf("mode %s must not invent output.md", mode)
		}
	}

	run("abs", "# from absolute rel_path\n", true)
	run("nested", "# from nested rel_path\n", true)
	run("dot", "# from dot rel_path\n", true)
	run("missing", "", false)
}

func TestPiAgentRemoteRunner_PropagatesRetryable(t *testing.T) {
	dir := t.TempDir()
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		_ = json.NewEncoder(w).Encode(map[string]any{
			"ok":              false,
			"retryable":       true,
			"fallback_reason": "Connection error.",
			"patches":         []any{},
		})
	}))
	defer ts.Close()
	res, err := agent.NewBackend("pi-agent", &config.Config{
		AgentBackend:     "pi-agent",
		PiAgentRunnerURL: ts.URL,
		PiAgentModel:     "MiniMax-M3",
		PiAgentProvider:  "minimax",
		AgentTimeout:     5 * time.Second,
	}).Execute(context.Background(), agent.Request{
		WorkDir: dir,
		Prompt:  "draft",
		Targets: []string{"output.md"},
	})
	if err != nil {
		t.Fatal(err)
	}
	if res.Success || !res.Retryable {
		t.Fatalf("want retryable failure, success=%v retryable=%v reason=%s", res.Success, res.Retryable, res.ErrorReason)
	}
	if _, serr := os.Stat(filepath.Join(dir, "output.md")); serr == nil {
		t.Fatal("must not invent output.md")
	}
}

func TestPiAgentRemoteRunner_OldSettleLieIsRetryable(t *testing.T) {
	dir := t.TempDir()
	log := "Outcome: SUCCESS\n" +
		`{"type":"message_end","message":{"stopReason":"error","errorMessage":"terminated"}}` + "\n" +
		`{"type":"auto_retry_end","success":false,"attempt":3,"finalError":"Connection error."}` + "\n" +
		`{"type":"agent_settled"}` + "\n"
	if err := os.WriteFile(filepath.Join(dir, "execution.log"), []byte(log), 0o644); err != nil {
		t.Fatal(err)
	}
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		_ = json.NewEncoder(w).Encode(map[string]any{
			"ok": true,
			"patches": []map[string]string{{
				"rel_path": "execution.log",
				"content":  "Outcome: SUCCESS\n",
			}},
		})
	}))
	defer ts.Close()
	res, err := agent.NewBackend("pi-agent", &config.Config{
		AgentBackend:     "pi-agent",
		PiAgentRunnerURL: ts.URL,
		PiAgentModel:     "MiniMax-M3",
		PiAgentProvider:  "minimax",
		AgentTimeout:     5 * time.Second,
	}).Execute(context.Background(), agent.Request{
		WorkDir: dir,
		Prompt:  "draft",
		Targets: []string{"output.md"},
	})
	if err != nil {
		t.Fatal(err)
	}
	if res.Success {
		t.Fatal("process-0 settle without output.md must not succeed")
	}
	if !res.Retryable {
		t.Fatalf("old runner lie + provider trace must be retryable, reason=%s", res.ErrorReason)
	}
	if _, serr := os.Stat(filepath.Join(dir, "output.md")); serr == nil {
		t.Fatal("must not reconstruct output.md from truncated write args")
	}
}