// fetch_openrouter.go - OpenRouter 模型数据采集器
// Phase 1 单数据源采集器，抓取模型基础信息与价格信息
package main

import (
	"database/sql"
	"encoding/json"
	"flag"
	"fmt"
	"io"
	"net/http"
	"os"
	"time"

	_ "github.com/lib/pq"
)

// Config 采集配置
type Config struct {
	APIKey     string
	APIURL     string
	OutPath    string
	MaxRetries int
	TimeoutSec int
	// PostgreSQL 连接参数（新增）
	DBConn string // e.g. "host=/var/run/postgresql dbname=llm_intelligence sslmode=disable"
}

// OpenRouter API 响应结构（仅关键字段）
type APIResponse struct {
	Data []ModelInfo `json:"data"`
}

type ModelInfo struct {
	ID            string         `json:"id"`
	Name          string         `json:"name,omitempty"`
	Created       int64          `json:"created,omitempty"`
	Description   string         `json:"description,omitempty"`
	ContextLength int            `json:"context_length,omitempty"`
	Capabilities  []string      `json:"capabilities,omitempty"`
	Pricing       ModelPricing   `json:"pricing,omitempty"`
}

type ModelPricing struct {
	Input  float64 `json:"input,omitempty"`
	Output float64 `json:"output,omitempty"`
}

func main() {
	cfg := parseArgs()
	if err := run(cfg); err != nil {
		fmt.Fprintf(os.Stderr, "采集失败: %v\n", err)
		os.Exit(1)
	}
}

func parseArgs() Config {
	apiKey := flag.String("api-key", "", "OpenRouter API Key（建议通过环境变量注入）")
	apiURL := flag.String("api-url", "https://openrouter.ai/api/v1/models", "API 地址")
	outPath := flag.String("out", "models.json", "输出文件路径")
	maxRetries := flag.Int("retry", 3, "最大重试次数")
	timeoutSec := flag.Int("timeout", 30, "请求超时（秒）")
	dbConn := flag.String("db", os.Getenv("DATABASE_URL"), "PostgreSQL 连接字符串（默认从 DATABASE_URL 环境变量读取）")
	flag.Parse()
	return Config{
		APIKey:     *apiKey,
		APIURL:     *apiURL,
		OutPath:    *outPath,
		MaxRetries: *maxRetries,
		TimeoutSec: *timeoutSec,
		DBConn:     *dbConn,
	}
}

func run(cfg Config) error {
	models, err := fetchModels(cfg)
	if err != nil {
		return err
	}
	// 优先写入 PostgreSQL；若配置了 DBConn 则入库
	if cfg.DBConn != "" {
		if err := summarizeDB(cfg.DBConn, models); err != nil {
			fmt.Fprintf(os.Stderr, "警告: PostgreSQL 写入失败: %v\n", err)
			fmt.Fprintln(os.Stderr, "降级为仅写入 JSON")
		}
	}
	return summarize(cfg.OutPath, models)
}

// fetchModels 抓取 OpenRouter 模型列表
func fetchModels(cfg Config) ([]ModelInfo, error) {
	// 无 API Key 时返回模拟数据（写入由后续 summarize 统一处理）
	if cfg.APIKey == "" {
		fmt.Println("警告: 未提供 API Key，使用模拟数据")
		return []ModelInfo{
			{ID: "openai/gpt-4o", ContextLength: 128000,
				Pricing: ModelPricing{Input: 2.5, Output: 10.0}},
			{ID: "anthropic/claude-3.5-sonnet:free", ContextLength: 200000,
				Pricing: ModelPricing{}},
		}, nil
	}

	client := &http.Client{Timeout: time.Duration(cfg.TimeoutSec) * time.Second}
	req, err := http.NewRequest("GET", cfg.APIURL, nil)
	if err != nil {
		return nil, fmt.Errorf("构造请求失败: %w", err)
	}
	req.Header.Set("Authorization", "Bearer "+cfg.APIKey)
	req.Header.Set("Content-Type", "application/json")

	var resp *http.Response
	for i := 0; i <= cfg.MaxRetries; i++ {
		resp, err = client.Do(req)
		if err == nil {
			break
		}
		if i < cfg.MaxRetries {
			time.Sleep(time.Duration(i+1) * time.Second)
		}
	}
	if err != nil {
		return nil, fmt.Errorf("请求失败: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		body, _ := io.ReadAll(resp.Body)
		return nil, fmt.Errorf("非 200 响应: %d %s", resp.StatusCode, string(body))
	}

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, fmt.Errorf("读取响应失败: %w", err)
	}

	// 健壮解析，兼容字段缺失和结构差异
	models, err := parseModels(body)
	if err != nil {
		return nil, fmt.Errorf("JSON 解析失败: %w", err)
	}

	// TODO: 字段标准化映射（OpenRouter id → 标准厂商名、模型名）
	return models, nil
}

// parseModels 健壮解析模型列表，兼容字段缺失/类型不一致/嵌套结构差异
func parseModels(raw []byte) ([]ModelInfo, error) {
	var wrapper struct {
		Data json.RawMessage `json:"data"`
	}
	if err := json.Unmarshal(raw, &wrapper); err != nil {
		return nil, fmt.Errorf("解析 data 字段失败: %w", err)
	}
	// data 为数组，每元素字段可能不同，统一用 map[string]any 兼容
	var rawItems []any
	if err := json.Unmarshal(wrapper.Data, &rawItems); err != nil {
		return nil, fmt.Errorf("解析模型数组失败: %w", err)
	}

	models := make([]ModelInfo, 0, len(rawItems))
	for _, item := range rawItems {
		m, ok := item.(map[string]any)
		if !ok {
			continue // 跳过非法条目
		}
		model := ModelInfo{
		ID:   getString(m, "id"),
		Name: getString(m, "name"),
	}
		if model.ID == "" {
			continue // id 为必填
		}

		// pricing 可能为嵌套对象（如 {openrouter: {input: 1}}），尝试多路径取值
		if p, ok := m["pricing"].(map[string]any); ok {
			model.Pricing.Input = getPrice(p, "input", "prompt")
			model.Pricing.Output = getPrice(p, "output", "completion")
		}

		model.ContextLength = getInt(m, "context_length")
		model.Description = getString(m, "description")
		model.Created = getInt64(m, "created")

		if caps, ok := m["capabilities"].([]any); ok {
			for _, c := range caps {
				if s, ok := c.(string); ok {
					model.Capabilities = append(model.Capabilities, s)
				}
			}
		}
		models = append(models, model)
	}
	return models, nil
}

func getString(m map[string]any, key string) string {
	if v, ok := m[key].(string); ok {
		return v
	}
	return ""
}

func getInt(m map[string]any, key string) int {
	if v, ok := m[key].(float64); ok {
		return int(v)
	}
	return 0
}

func getInt64(m map[string]any, key string) int64 {
	if v, ok := m[key].(float64); ok {
		return int64(v)
	}
	return 0
}

// getPrice 多路径取值，兼容不同嵌套结构（如 {input:1} 或 {openrouter:{input:1}}）
func getPrice(m map[string]any, keys ...string) float64 {
	for _, k := range keys {
		if v, ok := m[k].(float64); ok {
			return v
		}
	}
	return 0
}

// summarize 输出采集摘要到 JSON 文件（保持向后兼容）
func summarize(outPath string, models []ModelInfo) error {
	return writeJSON(outPath, models)
}

// summarizeDB 将采集结果写入 PostgreSQL（models + model_prices 表）
func summarizeDB(connStr string, models []ModelInfo) error {
	db, err := sql.Open("postgres", connStr)
	if err != nil {
		return fmt.Errorf("连接数据库失败: %w", err)
	}
	defer db.Close()

	if err := db.Ping(); err != nil {
		return fmt.Errorf("ping 数据库失败: %w", err)
	}

	tx, err := db.Begin()
	if err != nil {
		return fmt.Errorf("开启事务失败: %w", err)
	}
	defer tx.Rollback()

	now := time.Now()
	insertedModels := 0
	insertedPrices := 0

	for _, m := range models {
		isFree := len(m.ID) > 5 && m.ID[len(m.ID)-5:] == ":free"
		// upsert models 表
		var modelID int64
		err := tx.QueryRow(`
			INSERT INTO models (source, external_id, name, description, context_length, capabilities, created_at_source, is_free, status, raw_payload, created_at, updated_at)
			VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12)
			ON CONFLICT (external_id) DO UPDATE SET
				name = EXCLUDED.name,
				description = EXCLUDED.description,
				context_length = EXCLUDED.context_length,
				capabilities = EXCLUDED.capabilities,
				created_at_source = EXCLUDED.created_at_source,
				is_free = EXCLUDED.is_free,
				status = EXCLUDED.status,
				raw_payload = EXCLUDED.raw_payload,
				updated_at = $12
			RETURNING id
		`, "openrouter", m.ID, m.Name, m.Description, m.ContextLength,
			jsonCapabilities(m.Capabilities), m.Created, isFree, "active",
			rawPayload(m), now, now).Scan(&modelID)
		if err != nil {
			return fmt.Errorf("写入 models 失败 (%s): %w", m.ID, err)
		}
		insertedModels++

		// upsert model_prices 表（当天有效日期）
		effectiveDate := now.Format("2006-01-02")
		_, err = tx.Exec(`
			INSERT INTO model_prices (model_id, source, currency, input_price_per_mtok, output_price_per_mtok, effective_date, source_url, created_at)
			VALUES ($1, $2, $3, $4, $5, $6, $7, $8)
			ON CONFLICT (model_id, source, currency, effective_date) DO UPDATE SET
				input_price_per_mtok = EXCLUDED.input_price_per_mtok,
				output_price_per_mtok = EXCLUDED.output_price_per_mtok,
				created_at = EXCLUDED.created_at
		`, modelID, "openrouter", "USD", m.Pricing.Input, m.Pricing.Output, effectiveDate, "https://openrouter.ai/api/v1/models", now)
		if err != nil {
			return fmt.Errorf("写入 model_prices 失败 (%s): %w", m.ID, err)
		}
		insertedPrices++
	}

	if err := tx.Commit(); err != nil {
		return fmt.Errorf("提交事务失败: %w", err)
	}

	fmt.Printf("PostgreSQL 写入完成: %d models, %d prices\n", insertedModels, insertedPrices)
	return nil
}

func jsonCapabilities(caps []string) []byte {
	if len(caps) == 0 {
		return []byte("[]")
	}
	b, _ := json.Marshal(caps)
	return b
}

func rawPayload(m ModelInfo) []byte {
	b, _ := json.Marshal(m)
	return b
}

// writeJSON 统一写入 JSON 文件（含摘要信息）
func writeJSON(outPath string, models []ModelInfo) error {
	total := len(models)
	var freeCnt, paidCnt int
	for _, m := range models {
		if len(m.ID) > 5 && m.ID[len(m.ID)-5:] == ":free" {
			freeCnt++
		} else if m.Pricing.Input > 0 || m.Pricing.Output > 0 {
			paidCnt++
		}
	}

	summary := fmt.Sprintf("采集完成: 共 %d 模型（免费 %d / 付费 %d）\n", total, freeCnt, paidCnt)
	fmt.Print(summary)

	out, err := os.Create(outPath)
	if err != nil {
		return fmt.Errorf("创建输出文件失败: %w", err)
	}
	defer out.Close()

	enc := json.NewEncoder(out)
	enc.SetIndent("", "  ")
	if err := enc.Encode(map[string]any{
		"generated_at": time.Now().Format(time.RFC3339),
		"total":        total,
		"free":         freeCnt,
		"paid":         paidCnt,
		"models":       models,
	}); err != nil {
		return fmt.Errorf("写入 JSON 失败: %w", err)
	}
	fmt.Printf("结果已写入: %s\n", outPath)
	return nil
}