package edgecmd

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"net"
	"net/http"
	"strings"
	"time"

	"github.com/spf13/cobra"
)

func smokeCmd() *cobra.Command {
	c := &cobra.Command{
		Use:   "smoke",
		Short: "Run verification and smoke tests",
		Long: `Run diagnostic smoke tests to verify the connectivity and functionality of IOP Edge components.

Typical local flow:
  1. iop-edge config init
  2. iop-edge node register <node-id>
  3. iop-edge serve
  4. iop-edge smoke openai --model <model>`,
		Example: `  iop-edge smoke openai --model gemma4:26b
  iop-edge smoke openai --model gemma4:26b --base-url http://127.0.0.1:8080`,
	}
	c.AddCommand(smokeOpenAICmd())
	return c
}

var (
	smokeModel   string
	smokeBaseURL string
	smokePrompt  string
	smokeTimeout string
)

type openAIModel struct {
	ID      string `json:"id"`
	Object  string `json:"object"`
	Created int64  `json:"created"`
	OwnedBy string `json:"owned_by"`
}

type openAIModelsResponse struct {
	Object string        `json:"object"`
	Data   []openAIModel `json:"data"`
}

type chatCompletionMessage struct {
	Role    string `json:"role"`
	Content string `json:"content"`
}

type chatCompletionChoice struct {
	Index        int                   `json:"index"`
	Message      chatCompletionMessage `json:"message"`
	FinishReason string                `json:"finish_reason"`
}

type chatCompletionUsage struct {
	PromptTokens     int `json:"prompt_tokens"`
	CompletionTokens int `json:"completion_tokens"`
	TotalTokens      int `json:"total_tokens"`
}

type chatCompletionResponse struct {
	ID      string                 `json:"id"`
	Object  string                 `json:"object"`
	Created int64                  `json:"created"`
	Model   string                 `json:"model"`
	Choices []chatCompletionChoice `json:"choices"`
	Usage   *chatCompletionUsage   `json:"usage"`
}

func resolveSmokeBaseURL(cmd *cobra.Command) (string, error) {
	if smokeBaseURL != "" {
		return strings.TrimSuffix(smokeBaseURL, "/"), nil
	}
	cfg, _, err := LoadEdgeConfig(cmd)
	if err != nil {
		return "", fmt.Errorf("failed to load edge config to resolve base URL (pass --base-url to override): %w", err)
	}
	listen := cfg.OpenAI.Listen
	if listen == "" {
		listen = "127.0.0.1:8080"
	}
	host, port, err := net.SplitHostPort(listen)
	if err != nil {
		return "http://127.0.0.1:8080", nil
	}
	if host == "0.0.0.0" || host == "" {
		host = "127.0.0.1"
	}
	return "http://" + net.JoinHostPort(host, port), nil
}

func smokeOpenAICmd() *cobra.Command {
	c := &cobra.Command{
		Use:   "openai",
		Short: "Perform OpenAI-compatible endpoint smoke test",
		Long: `Validate the IOP Edge OpenAI-compatible HTTP API surface.
It runs a three-step diagnostics check:
  1. Checks GET /healthz (server status).
  2. Checks GET /v1/models (advertised model compatibility).
  3. Checks POST /v1/chat/completions (inference request processing).

If --base-url is not provided, it auto-discovers the OpenAI URL from the effective config's listen address.`,
		Example: `  iop-edge smoke openai --model gemma4:26b
  iop-edge smoke openai --model gemma4:26b --base-url http://127.0.0.1:8080 --prompt "say hello" --timeout 15s`,
		RunE: func(cmd *cobra.Command, _ []string) error {
			baseURL, err := resolveSmokeBaseURL(cmd)
			if err != nil {
				return err
			}

			timeoutDur := 10 * time.Second
			if smokeTimeout != "" {
				d, err := time.ParseDuration(smokeTimeout)
				if err != nil {
					return fmt.Errorf("invalid timeout duration: %w", err)
				}
				timeoutDur = d
			}

			client := &http.Client{
				Timeout: timeoutDur,
			}

			fmt.Fprintf(cmd.OutOrStdout(), "IOP Edge OpenAI Smoke Test\n")
			fmt.Fprintf(cmd.OutOrStdout(), "========================================\n")
			fmt.Fprintf(cmd.OutOrStdout(), "Target Endpoint: %s\n", baseURL)
			fmt.Fprintf(cmd.OutOrStdout(), "Target Model:    %s\n", smokeModel)
			fmt.Fprintf(cmd.OutOrStdout(), "Timeout:         %s\n\n", timeoutDur)

			fmt.Fprintf(cmd.OutOrStdout(), "Step 1: Checking /healthz ... ")
			healthURL := baseURL + "/healthz"
			resp, err := client.Get(healthURL)
			if err != nil {
				fmt.Fprintln(cmd.OutOrStdout(), "[FAILED]")
				return fmt.Errorf("GET %s failed: %w (make sure the edge server is running)", healthURL, err)
			}
			defer resp.Body.Close()
			if resp.StatusCode != http.StatusOK {
				body, _ := io.ReadAll(resp.Body)
				fmt.Fprintln(cmd.OutOrStdout(), "[FAILED]")
				return fmt.Errorf("GET %s returned non-200 status %d: %s", healthURL, resp.StatusCode, string(body))
			}
			var healthData map[string]interface{}
			if err := json.NewDecoder(resp.Body).Decode(&healthData); err != nil {
				fmt.Fprintln(cmd.OutOrStdout(), "[FAILED]")
				return fmt.Errorf("failed to parse /healthz JSON response: %w", err)
			}
			fmt.Fprintln(cmd.OutOrStdout(), "[OK]")

			fmt.Fprintf(cmd.OutOrStdout(), "Step 2: Checking /v1/models ... ")
			modelsURL := baseURL + "/v1/models"
			resp, err = client.Get(modelsURL)
			if err != nil {
				fmt.Fprintln(cmd.OutOrStdout(), "[FAILED]")
				return fmt.Errorf("GET %s failed: %w", modelsURL, err)
			}
			defer resp.Body.Close()
			if resp.StatusCode != http.StatusOK {
				body, _ := io.ReadAll(resp.Body)
				fmt.Fprintln(cmd.OutOrStdout(), "[FAILED]")
				return fmt.Errorf("GET %s returned non-200 status %d: %s", modelsURL, resp.StatusCode, string(body))
			}
			var modelsResp openAIModelsResponse
			if err := json.NewDecoder(resp.Body).Decode(&modelsResp); err != nil {
				fmt.Fprintln(cmd.OutOrStdout(), "[FAILED]")
				return fmt.Errorf("failed to parse /v1/models JSON response: %w", err)
			}
			modelIDs := make([]string, 0, len(modelsResp.Data))
			modelMatched := false
			for _, m := range modelsResp.Data {
				modelIDs = append(modelIDs, m.ID)
				if m.ID == smokeModel {
					modelMatched = true
				}
			}
			fmt.Fprintf(cmd.OutOrStdout(), "[OK] (found models: %s)\n", strings.Join(modelIDs, ", "))
			if !modelMatched {
				fmt.Fprintf(cmd.OutOrStdout(), "WARNING: Target model %q is not advertised by /v1/models (advertised: %s)\n", smokeModel, strings.Join(modelIDs, ", "))
			}

			fmt.Fprintf(cmd.OutOrStdout(), "Step 3: Checking /v1/chat/completions ... ")
			prompt := smokePrompt
			if prompt == "" {
				prompt = "ping"
			}
			reqPayload := map[string]interface{}{
				"model": smokeModel,
				"messages": []map[string]string{
					{"role": "user", "content": prompt},
				},
				"stream": false,
			}
			payloadBytes, err := json.Marshal(reqPayload)
			if err != nil {
				return fmt.Errorf("failed to marshal request payload: %w", err)
			}

			chatURL := baseURL + "/v1/chat/completions"
			resp, err = client.Post(chatURL, "application/json", bytes.NewReader(payloadBytes))
			if err != nil {
				fmt.Fprintln(cmd.OutOrStdout(), "[FAILED]")
				return fmt.Errorf("POST %s failed: %w (make sure active nodes are online)", chatURL, err)
			}
			defer resp.Body.Close()
			if resp.StatusCode != http.StatusOK {
				body, _ := io.ReadAll(resp.Body)
				fmt.Fprintln(cmd.OutOrStdout(), "[FAILED]")
				return fmt.Errorf("POST %s returned non-200 status %d: %s", chatURL, resp.StatusCode, string(body))
			}
			var chatResp chatCompletionResponse
			if err := json.NewDecoder(resp.Body).Decode(&chatResp); err != nil {
				fmt.Fprintln(cmd.OutOrStdout(), "[FAILED]")
				return fmt.Errorf("failed to parse /v1/chat/completions JSON response: %w", err)
			}
			if len(chatResp.Choices) == 0 {
				fmt.Fprintln(cmd.OutOrStdout(), "[FAILED]")
				return fmt.Errorf("POST %s returned empty choices", chatURL)
			}
			content := chatResp.Choices[0].Message.Content
			if strings.TrimSpace(content) == "" {
				fmt.Fprintln(cmd.OutOrStdout(), "[FAILED]")
				return fmt.Errorf("POST %s returned empty assistant message content", chatURL)
			}
			fmt.Fprintf(cmd.OutOrStdout(), "[OK]\n")
			fmt.Fprintf(cmd.OutOrStdout(), "Response Content: %q\n\n", content)
			fmt.Fprintf(cmd.OutOrStdout(), "IOP Edge OpenAI Smoke Test SUCCESS!\n")

			return nil
		},
	}

	c.Flags().StringVar(&smokeModel, "model", "", "model identifier to check (required)")
	c.Flags().StringVar(&smokeBaseURL, "base-url", "", "override OpenAI base URL (e.g. http://127.0.0.1:8080)")
	c.Flags().StringVar(&smokePrompt, "prompt", "ping", "prompt text to send")
	c.Flags().StringVar(&smokeTimeout, "timeout", "10s", "client timeout duration")
	c.MarkFlagRequired("model")

	return c
}