package processing

import (
	"fmt"
	"strings"
)

// openAIErrorBody is the error object returned by OpenAI-compatible APIs.
type openAIErrorBody struct {
	Message string `json:"message"`
	Type    string `json:"type"`
	Code    any    `json:"code"` // string or number depending on provider
	Param   string `json:"param"`
}

func (e *openAIErrorBody) codeString() string {
	if e == nil {
		return ""
	}
	switch v := e.Code.(type) {
	case string:
		return strings.TrimSpace(v)
	case float64:
		if v == float64(int64(v)) {
			return fmt.Sprintf("%d", int64(v))
		}
		return fmt.Sprintf("%g", v)
	case int:
		return fmt.Sprintf("%d", v)
	default:
		return ""
	}
}

// formatOpenAIHTTPError turns an upstream HTTP error into a short, secret-safe
// operator message. Intentionally avoids embedding model ids (gpt-…) so
// TruncateError / mapPublicErrorCode do not collapse useful validation text to
// "processing_failed".
func formatOpenAIHTTPError(status int, errObj *openAIErrorBody) string {
	msg := ""
	code := ""
	param := ""
	typ := ""
	if errObj != nil {
		msg = strings.TrimSpace(errObj.Message)
		code = errObj.codeString()
		param = strings.TrimSpace(errObj.Param)
		typ = strings.TrimSpace(errObj.Type)
	}
	lower := strings.ToLower(msg)
	codeLower := strings.ToLower(code)
	paramLower := strings.ToLower(param)
	typLower := strings.ToLower(typ)

	switch {
	case status == 401 || codeLower == "invalid_api_key" ||
		strings.Contains(lower, "invalid api key") ||
		strings.Contains(lower, "incorrect api key"):
		return "AI provider rejected the API key"
	case status == 403:
		return "AI provider forbidden the request"
	// OpenAI returns HTTP 429 for BOTH true rate limits and missing prepaid
	// credits (insufficient_quota) — check quota BEFORE treating 429 as RPM.
	case codeLower == "insufficient_quota" || typLower == "insufficient_quota" ||
		strings.Contains(lower, "insufficient_quota") ||
		strings.Contains(lower, "exceeded your current quota") ||
		strings.Contains(lower, "check your plan and billing"):
		return "API billing/quota empty — add prepaid API credits in Platform billing (not ChatGPT Plus)"
	case codeLower == "rate_limit_exceeded" ||
		strings.Contains(lower, "rate limit reached") ||
		strings.Contains(lower, "rate_limit_exceeded"):
		return "AI provider rate limited — retry later"
	case status == 429:
		// Bare 429 with no body fields — still often quota on new accounts.
		return "API HTTP 429 — usually empty Platform billing/credits (not ChatGPT Plus); add prepaid credits then retry"
	case strings.Contains(lower, "does not exist") || strings.Contains(lower, "do not have access") ||
		codeLower == "model_not_found":
		return "model not found or API key lacks access — check model name and project permissions"
	case strings.Contains(lower, "max_tokens") && strings.Contains(lower, "max_completion"):
		return "model requires completion-token budget (legacy token cap unsupported)"
	case paramLower == "temperature" || strings.Contains(lower, "temperature"):
		return "model rejects custom temperature — omit temperature for reasoning chat models"
	case paramLower == "max_tokens" || (strings.Contains(lower, "unsupported parameter") && strings.Contains(lower, "max_tokens")):
		return "model rejects legacy token cap — use completion-token budget"
	case paramLower == "reasoning_effort" || strings.Contains(lower, "reasoning_effort"):
		return "model rejected reasoning effort — try none/low or omit"
	case strings.Contains(lower, "unsupported parameter") || strings.Contains(lower, "unsupported value"):
		if param != "" {
			return fmt.Sprintf("unsupported chat parameter %q", param)
		}
		return "unsupported chat parameter for this model"
	case status >= 500:
		return "AI provider temporarily unavailable (server error)"
	}

	// Prefer structured fields over raw message (raw often embeds model ids / urls).
	if code != "" && param != "" {
		return fmt.Sprintf("provider http %d (%s param=%s)", status, code, param)
	}
	if code != "" {
		return fmt.Sprintf("provider http %d (%s)", status, code)
	}
	if typ != "" {
		return fmt.Sprintf("provider http %d (%s)", status, typ)
	}
	if status > 0 {
		return fmt.Sprintf("provider http %d", status)
	}
	return "provider request failed"
}

// ProbeCompleteOptions is the Chat Completions budget for admin connection tests.
// Explicit max_completion_tokens + reasoning_effort=none avoids GPT-5.6 defaults
// spending the budget on hidden reasoning for a one-token "ok" reply.
func ProbeCompleteOptions() CompleteOptions {
	return CompleteOptions{
		MaxTokens:       64,
		ReasoningEffort: "none",
	}
}

// openAIErrorIsRetryableRateLimit is true only for genuine RPM/TPM limits.
// HTTP 429 + insufficient_quota (empty prepaid billing) must not be retried.
func openAIErrorIsRetryableRateLimit(errObj *openAIErrorBody) bool {
	if errObj == nil {
		return false
	}
	code := strings.ToLower(errObj.codeString())
	typ := strings.ToLower(strings.TrimSpace(errObj.Type))
	msg := strings.ToLower(strings.TrimSpace(errObj.Message))
	if code == "insufficient_quota" || typ == "insufficient_quota" ||
		strings.Contains(msg, "insufficient_quota") ||
		strings.Contains(msg, "exceeded your current quota") ||
		strings.Contains(msg, "check your plan and billing") {
		return false
	}
	return code == "rate_limit_exceeded" ||
		strings.Contains(msg, "rate limit reached") ||
		strings.Contains(msg, "rate_limit_exceeded")
}