package ckprompt

import (
	"bytes"
	"context"
	"encoding/json"
	"errors"
	"io"
	"reflect"
	"strings"
	"testing"

	"go.maximumdirect.net/ckconfig"
	commandkit "go.maximumdirect.net/commandkit"
	promptkit "go.maximumdirect.net/promptkit"
)

func jsonValue(t *testing.T, value any) any {
	t.Helper()
	data, err := json.Marshal(value)
	if err != nil {
		t.Fatal(err)
	}
	decoder := json.NewDecoder(bytes.NewReader(data))
	decoder.UseNumber()
	var result any
	if err := decoder.Decode(&result); err != nil {
		t.Fatal(err)
	}
	return result
}

func TestResourceInspectionsForwardNativeReports(t *testing.T) {
	zero := 0
	no := false
	empty := ""
	inputs := []promptkit.PromptInputInspection{{Name: "topic", Required: &no}}
	extra := map[string]any{}
	prompt := &promptkit.PromptInspection{PromptID: "p", PromptHash: "hash", Description: &empty, Inputs: &inputs, Messages: []promptkit.PromptMessageInspection{{Role: "user", Content: "captured {{.topic}}"}}}
	profile := &promptkit.ProfileInspection{ProfileID: "p", Temperature: nil, MaxTokens: &zero, APIKeyRequired: &no, ExtraParams: &extra}
	backend := &promptkit.BackendInspection{BackendID: "b", Endpoint: "https://example.invalid", QueueCapacity: &zero, ExtraParams: &extra}
	var selections []ckconfig.Selection
	calls := 0
	suite := Suite[struct{}, struct{}]{
		InspectPrompt: func(_ context.Context, r PromptRequest, _, _ struct{}) (commandkit.Acquired[*promptkit.PromptInspection], error) {
			calls++
			selections = append(selections, r.Selection)
			if r.ID != "p" {
				t.Errorf("prompt ID %q", r.ID)
			}
			return commandkit.Acquired[*promptkit.PromptInspection]{Value: prompt}, nil
		},
		InspectProfile: func(_ context.Context, r ProfileRequest, _, _ struct{}) (commandkit.Acquired[*promptkit.ProfileInspection], error) {
			calls++
			selections = append(selections, r.Selection)
			if r.ID != "p" {
				t.Errorf("profile ID %q", r.ID)
			}
			return commandkit.Acquired[*promptkit.ProfileInspection]{Value: profile}, nil
		},
		InspectBackend: func(_ context.Context, r BackendRequest, _, _ struct{}) (commandkit.Acquired[*promptkit.BackendInspection], error) {
			calls++
			selections = append(selections, r.Selection)
			if r.ID != "b" {
				t.Errorf("backend ID %q", r.ID)
			}
			return commandkit.Acquired[*promptkit.BackendInspection]{Value: backend}, nil
		},
	}
	app := newPromptTestApp(t, Command(suite), commandkit.Completion("example"))
	for _, kind := range []struct {
		name, id string
		value    any
	}{{"prompt", "p", prompt}, {"profile", "p", profile}, {"backend", "b", backend}} {
		for _, format := range []string{"text", "yaml", "json"} {
			t.Run(kind.name+"/"+format, func(t *testing.T) {
				var out bytes.Buffer
				outcome := app.Execute(t.Context(), []string{"promptkit", "show", kind.name, kind.id, "--config=fixture", "--format=" + format}, commandkit.Streams{Out: &out, Err: io.Discard})
				if outcome.Status != 0 {
					t.Fatalf("%#v, %s", outcome, out.String())
				}
				var got any
				var err error
				if format == "json" {
					d := json.NewDecoder(&out)
					d.UseNumber()
					err = d.Decode(&got)
				} else {
					got, err = commandkit.DecodeYAMLReport(&out)
				}
				if err != nil || !reflect.DeepEqual(got, jsonValue(t, kind.value)) {
					t.Fatalf("got %#v, %v; want %#v", got, err, jsonValue(t, kind.value))
				}
			})
		}
	}
	for _, selection := range selections {
		if !selection.Config.Set || selection.Config.Value != "fixture" {
			t.Fatalf("selection %#v", selection)
		}
	}
	before := calls
	for _, argv := range [][]string{{"promptkit", "show", "backend", "--help"}, {"__complete", "promptkit", "show", "backend", ""}} {
		var help bytes.Buffer
		result := app.Execute(t.Context(), argv, commandkit.Streams{Out: &help, Err: io.Discard})
		if result.Status != 0 || calls != before {
			t.Fatalf("%v: %#v calls %d", argv, result, calls)
		}
		if argv[0] == "promptkit" && !strings.Contains(help.String(), "BACKEND_ID") {
			t.Fatalf("backend help = %q", help.String())
		}
	}
}

func TestBackendInspectionOptionalAndNativeErrorIdentity(t *testing.T) {
	calls := 0
	engine := adapterEngine(t)
	suite := FromEngine(func(context.Context, ckconfig.Selection, struct{}, struct{}) (*promptkit.Engine, error) {
		calls++
		return engine, nil
	})
	backendOnly := Suite[struct{}, struct{}]{InspectBackend: suite.InspectBackend}
	app := newPromptTestApp(t, Command(backendOnly))
	result := app.Execute(t.Context(), []string{"promptkit", "show", "backend", "missing"}, commandkit.Streams{Err: io.Discard})
	if !errors.Is(result.Cause, promptkit.ErrBackendNotFound) || result.Kind != commandkit.OutcomeOperational || calls != 1 {
		t.Fatalf("outcome %#v calls %d", result, calls)
	}
	without := newPromptTestApp(t, Command(Suite[struct{}, struct{}]{InspectPrompt: suite.InspectPrompt}))
	result = without.Execute(t.Context(), []string{"promptkit", "show", "backend", "missing"}, commandkit.Streams{Err: io.Discard})
	if result.Kind != commandkit.OutcomeUsage || calls != 1 {
		t.Fatalf("outcome %#v calls %d", result, calls)
	}
}

func TestEngineInspectionReportsMatchNativeResults(t *testing.T) {
	t.Setenv("PROMPTKIT_ADAPTER_TEST_KEY", "private-credential-value")
	engine := adapterEngine(t)
	calls := 0
	native := FromEngine(func(context.Context, ckconfig.Selection, struct{}, struct{}) (*promptkit.Engine, error) {
		calls++
		return engine, nil
	})
	suite := Suite[struct{}, struct{}]{InspectPrompt: native.InspectPrompt, InspectProfile: native.InspectProfile, InspectBackend: native.InspectBackend}
	app := newPromptTestApp(t, Command(suite))
	ctx := t.Context()
	prompt, err := engine.InspectPrompt(ctx, "briefing")
	if err != nil {
		t.Fatal(err)
	}
	profile, err := engine.InspectProfile(ctx, "default")
	if err != nil {
		t.Fatal(err)
	}
	backend, err := engine.InspectBackend(ctx, "local")
	if err != nil {
		t.Fatal(err)
	}
	for _, tc := range []struct {
		name, id string
		want     any
	}{{"prompt", "briefing", prompt}, {"profile", "default", profile}, {"backend", "local", backend}} {
		t.Run(tc.name, func(t *testing.T) {
			var out bytes.Buffer
			result := app.Execute(ctx, []string{"promptkit", "show", tc.name, tc.id, "--format=json"}, commandkit.Streams{Out: &out, Err: io.Discard})
			if bytes.Contains(out.Bytes(), []byte("private-credential-value")) {
				t.Fatal("resource report exposed a credential value")
			}
			var got any
			decoder := json.NewDecoder(&out)
			decoder.UseNumber()
			err := decoder.Decode(&got)
			if result.Status != 0 || err != nil || !reflect.DeepEqual(got, jsonValue(t, tc.want)) {
				t.Fatalf("result=%#v got=%#v err=%v want=%#v", result, got, err, jsonValue(t, tc.want))
			}
		})
	}
	if calls != 3 {
		t.Fatalf("loader calls %d", calls)
	}
}

func TestBackendInspectionPreservesDiagnosticsAndCause(t *testing.T) {
	cause := errors.New("backend lookup failed")
	app := newPromptTestApp(t, Command(Suite[struct{}, struct{}]{InspectBackend: func(context.Context, BackendRequest, struct{}, struct{}) (commandkit.Acquired[*promptkit.BackendInspection], error) {
		return commandkit.Acquired[*promptkit.BackendInspection]{Diagnostics: []commandkit.Diagnostic{commandkit.MessageDiagnostic(commandkit.SeverityWarning, "loader warning")}}, cause
	}}))
	var diagnostics bytes.Buffer
	result := app.Execute(t.Context(), []string{"promptkit", "show", "backend", "example", "--verbose"}, commandkit.Streams{Out: io.Discard, Err: &diagnostics})
	if !errors.Is(result.Cause, cause) || !strings.Contains(diagnostics.String(), "loader warning") {
		t.Fatalf("result=%#v diagnostics=%q", result, diagnostics.String())
	}
}