package api

import (
	"encoding/json"
	"fmt"
)

// ChainedVars holds auto-extracted fields from the most-recent response.
// Keys are formatted as "last_FIELD" (top-level) or "last_PARENT_FIELD"
// (one level of nesting). Use them in any request as {{last_id}}, etc.
//
// The map is replaced entirely on each successful response so stale values
// from a previous call do not bleed into unrelated requests.
var ChainedVars = make(map[string]string)

// ExtractChained parses body as a JSON object and populates ChainedVars.
// Non-JSON bodies are silently ignored.
func ExtractChained(body []byte) {
	var data map[string]interface{}
	if err := json.Unmarshal(body, &data); err != nil {
		return
	}
	next := make(map[string]string)
	flattenJSON(next, "last", data, 0)
	ChainedVars = next
}

// flattenJSON recursively walks obj up to maxDepth levels deep.
func flattenJSON(dst map[string]string, prefix string, obj map[string]interface{}, depth int) {
	if depth > 1 {
		return
	}
	for k, v := range obj {
		key := prefix + "_" + k
		switch val := v.(type) {
		case string:
			dst[key] = val
		case float64:
			if val == float64(int64(val)) {
				dst[key] = fmt.Sprintf("%d", int64(val))
			} else {
				dst[key] = fmt.Sprintf("%g", val)
			}
		case bool:
			if val {
				dst[key] = "true"
			} else {
				dst[key] = "false"
			}
		case map[string]interface{}:
			flattenJSON(dst, key, val, depth+1)
		}
	}
}