package clients

import (
	"context"
	"fmt"
	"strings"
	"time"
)

type SimulationClient struct{}

func (c SimulationClient) Run(ctx context.Context, request Request) (Response, error) {
	_ = ctx
	profile := simulationProfile(request)
	if profile == "retryable_failure" {
		return Response{}, &ClientError{Code: "server_error", Message: "simulated retryable failure", Retryable: true}
	}
	if profile == "fatal_failure" || profile == "non_retryable_failure" {
		return Response{}, &ClientError{Code: "bad_request", Message: "simulated non-retryable failure", Retryable: false}
	}
	responseStartedAt := time.Now()
	result := simulatedResult(request)
	responseFinishedAt := time.Now()
	return Response{
		Result:             result,
		RequestID:          requestIDFromResult(result),
		Usage:              simulatedUsage(request),
		Progress:           simulatedProgress(request),
		ResponseStartedAt:  responseStartedAt,
		ResponseFinishedAt: responseFinishedAt,
		ResponseDurationMS: responseDurationMS(responseStartedAt, responseFinishedAt),
	}, nil
}

func simulationProfile(request Request) string {
	if value := stringValue(request.Candidate.Credentials, "simulationFailure"); value != "" {
		return value
	}
	if value := stringValue(request.Candidate.PlatformConfig, "simulationFailure"); value != "" {
		return value
	}
	if value := stringValue(request.Body, "simulationProfile"); value != "" {
		return value
	}
	if value := stringValue(request.Body, "testProfile"); value != "" {
		return value
	}
	return "success"
}

func simulatedResult(request Request) map[string]any {
	switch request.Kind {
	case "chat.completions":
		return map[string]any{
			"id":      "chatcmpl-simulated",
			"object":  "chat.completion",
			"created": nowUnix(),
			"model":   request.Model,
			"choices": []any{map[string]any{
				"index":         0,
				"finish_reason": "stop",
				"message": map[string]any{
					"role":    "assistant",
					"content": fmt.Sprintf("simulation response from %s", request.Candidate.Provider),
				},
			}},
			"usage": map[string]any{"prompt_tokens": 12, "completion_tokens": 8, "total_tokens": 20},
		}
	case "responses":
		return map[string]any{
			"id":          "resp-simulated",
			"object":      "response",
			"created_at":  nowUnix(),
			"model":       request.Model,
			"output_text": fmt.Sprintf("simulation response from %s", request.Candidate.Provider),
			"usage":       map[string]any{"input_tokens": 12, "output_tokens": 8, "total_tokens": 20},
		}
	case "images.edits":
		return map[string]any{
			"id":      "img-edit-simulated",
			"created": nowUnix(),
			"model":   request.Model,
			"data": []any{map[string]any{
				"url":            "/static/simulation/image-edit.png",
				"revised_prompt": firstNonEmptyPrompt(request.Body, "simulation image edit"),
			}},
		}
	default:
		return map[string]any{
			"id":      "img-simulated",
			"created": nowUnix(),
			"model":   request.Model,
			"data": []any{map[string]any{
				"url":            "/static/simulation/image.png",
				"revised_prompt": firstNonEmptyPrompt(request.Body, "simulation image"),
			}},
		}
	}
}

func simulatedUsage(request Request) Usage {
	if request.ModelType == "chat" || request.Kind == "responses" {
		return Usage{InputTokens: 12, OutputTokens: 8, TotalTokens: 20}
	}
	return Usage{}
}

func simulatedProgress(request Request) []Progress {
	provider := request.Candidate.Provider
	if provider == "" {
		provider = "simulation"
	}
	return []Progress{
		{Phase: "normalizing", Progress: 0.2, Message: "request normalized", Payload: map[string]any{"provider": provider}},
		{Phase: "submitting", Progress: 0.55, Message: "simulation client submitted", Payload: map[string]any{"clientId": request.Candidate.ClientID}},
		{Phase: "fetching_result", Progress: 0.85, Message: "simulation result ready", Payload: map[string]any{"kind": request.Kind}},
	}
}

func firstNonEmptyPrompt(body map[string]any, fallback string) string {
	for _, key := range []string{"prompt", "input"} {
		if value := strings.TrimSpace(stringValue(body, key)); value != "" {
			return value
		}
	}
	return fallback
}