package httpadapter

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

	"gitea.maximumdirect.net/eric/scriptorium/internal/domain"
	"gitea.maximumdirect.net/eric/scriptorium/internal/profile"
	"gitea.maximumdirect.net/eric/scriptorium/internal/usecase"
)

type fakeRunner struct {
	result *domain.RunResult
	err    error
	last   domain.RunRequest
}

func (f *fakeRunner) Run(ctx context.Context, req domain.RunRequest) (*domain.RunResult, error) {
	f.last = req
	if f.err != nil {
		return nil, f.err
	}
	return f.result, nil
}

func TestHandlerPostRunsSuccess(t *testing.T) {
	start := time.Now().UTC()
	end := start.Add(2 * time.Second)
	r := &fakeRunner{result: &domain.RunResult{
		Artifact: domain.Artifact{
			Name:        "output",
			ContentType: "text/plain",
			Body:        []byte("hello"),
			Size:        5,
			Hash:        "abc",
		},
		Validation:     domain.ValidationResult{Status: domain.ValidationPassed, Mode: domain.ValidationBasic, IsValid: true},
		ProfileID:      "p1",
		ProfileVersion: "1.0.0",
		ModelName:      "m1",
		Endpoint:       "http://llm/v1",
		InputHashes:    map[string]string{"transcript": "h1"},
		PromptHash:     "ph",
		Usage:          domain.TokenUsage{PromptTokens: 1, CompletionTokens: 2, TotalTokens: 3},
		StartTime:      start,
		EndTime:        end,
		RawOutput:      "hello",
	}}

	h := NewHandler(r)

	body := []byte(`{
  "profile_id": "p1",
  "inputs": {
    "transcript": {"type": "file", "uri": "./t.md"}
  },
  "vars": {"k": "v"},
  "model": {"model": "gpt-x"}
}`)
	req := httptest.NewRequest(http.MethodPost, "/v1/runs", bytes.NewReader(body))
	w := httptest.NewRecorder()

	h.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d: %s", w.Code, w.Body.String())
	}

	var resp map[string]any
	if err := json.Unmarshal(w.Body.Bytes(), &resp); err != nil {
		t.Fatalf("invalid JSON response: %v", err)
	}

	artifact := resp["artifact"].(map[string]any)
	if artifact["body"] != "hello" {
		t.Fatalf("expected artifact body hello, got %#v", artifact["body"])
	}
	if resp["raw_model_output"] != "hello" {
		t.Fatalf("expected raw model output hello, got %#v", resp["raw_model_output"])
	}

	if r.last.ProfileID != "p1" {
		t.Fatalf("expected request profile_id p1, got %q", r.last.ProfileID)
	}
	if r.last.Model == nil || r.last.Model.Model != "gpt-x" {
		t.Fatalf("expected model override, got %#v", r.last.Model)
	}
}

func TestHandlerInvalidJSON(t *testing.T) {
	h := NewHandler(&fakeRunner{})
	req := httptest.NewRequest(http.MethodPost, "/v1/runs", bytes.NewBufferString("{"))
	w := httptest.NewRecorder()

	h.ServeHTTP(w, req)

	if w.Code != http.StatusBadRequest {
		t.Fatalf("expected 400, got %d", w.Code)
	}
}

func TestHandlerMissingProfileID(t *testing.T) {
	h := NewHandler(&fakeRunner{})
	req := httptest.NewRequest(http.MethodPost, "/v1/runs", bytes.NewBufferString(`{"inputs":{"x":{"type":"file","uri":"a"}}}`))
	w := httptest.NewRecorder()

	h.ServeHTTP(w, req)

	if w.Code != http.StatusBadRequest {
		t.Fatalf("expected 400, got %d", w.Code)
	}
}

func TestHandlerUsecaseErrorMapping(t *testing.T) {
	tests := []struct {
		name   string
		err    error
		status int
	}{
		{name: "profile not found", err: wrap(usecase.ErrProfileLoad, profile.ErrProfileNotFound), status: http.StatusNotFound},
		{name: "artifact", err: wrap(usecase.ErrArtifactLoad, fmt.Errorf("read failed")), status: http.StatusBadRequest},
		{name: "prompt", err: wrap(usecase.ErrPromptRender, fmt.Errorf("render failed")), status: http.StatusBadRequest},
		{name: "llm", err: wrap(usecase.ErrLLMGenerate, fmt.Errorf("llm failed")), status: http.StatusBadGateway},
		{name: "validation runtime", err: wrap(usecase.ErrValidation, fmt.Errorf("validator broke")), status: http.StatusInternalServerError},
	}

	for _, tc := range tests {
		t.Run(tc.name, func(t *testing.T) {
			h := NewHandler(&fakeRunner{err: tc.err})
			req := httptest.NewRequest(http.MethodPost, "/v1/runs", bytes.NewBufferString(`{"profile_id":"p","inputs":{"x":{"type":"file","uri":"a"}}}`))
			w := httptest.NewRecorder()

			h.ServeHTTP(w, req)

			if w.Code != tc.status {
				t.Fatalf("expected %d, got %d body=%s", tc.status, w.Code, w.Body.String())
			}
		})
	}
}

func TestHandlerValidationFailureStillSuccess(t *testing.T) {
	h := NewHandler(&fakeRunner{result: &domain.RunResult{
		Artifact:  domain.Artifact{Body: []byte("bad json")},
		RawOutput: "bad json",
		Validation: domain.ValidationResult{
			Status: domain.ValidationFailed,
			Mode:   domain.ValidationJSON,
			Errors: []string{"invalid JSON"},
		},
	}})

	req := httptest.NewRequest(http.MethodPost, "/v1/runs", bytes.NewBufferString(`{"profile_id":"p","inputs":{"x":{"type":"file","uri":"a"}}}`))
	w := httptest.NewRecorder()

	h.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d: %s", w.Code, w.Body.String())
	}
	var resp map[string]any
	if err := json.Unmarshal(w.Body.Bytes(), &resp); err != nil {
		t.Fatalf("invalid JSON response: %v", err)
	}
	validation := resp["validation"].(map[string]any)
	if status, ok := validation["Status"].(string); !ok || status != "failed" {
		t.Fatalf("expected validation Status=failed, got %#v", validation["Status"])
	}
}

func wrap(stage error, cause error) error {
	return fmt.Errorf("%w: %w", stage, cause)
}