package v1

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"strconv"

	"github.com/gin-gonic/gin"
)

func bindJSONWrappedOrRaw(c *gin.Context, wrapperKey string, target any) error {
	if c.Request.Body == nil {
		return fmt.Errorf("empty request body")
	}
	body, err := io.ReadAll(c.Request.Body)
	if err != nil {
		return err
	}
	c.Request.Body = io.NopCloser(bytes.NewReader(body))
	if len(bytes.TrimSpace(body)) == 0 {
		return fmt.Errorf("empty request body")
	}

	var wrapper map[string]json.RawMessage
	if err := json.Unmarshal(body, &wrapper); err == nil {
		if raw, ok := wrapper[wrapperKey]; ok && len(raw) > 0 && string(raw) != "null" {
			return json.Unmarshal(raw, target)
		}
	}
	return json.Unmarshal(body, target)
}

// parseUintParam extracts a uint path parameter from the Gin context.
func parseUintParam(c *gin.Context, param string) (uint, error) {
	val := c.Param(param)
	n, err := strconv.ParseUint(val, 10, 32)
	if err != nil {
		return 0, err
	}
	return uint(n), nil
}

func parseOptionalUintQueryParam(c *gin.Context, param string) (uint, error) {
	val := c.Query(param)
	if val == "" {
		return 0, nil
	}
	n, err := strconv.ParseUint(val, 10, 32)
	if err != nil {
		return 0, err
	}
	return uint(n), nil
}

func parseIntQueryDefault(c *gin.Context, param string, fallback int) (int, error) {
	val := c.Query(param)
	if val == "" {
		return fallback, nil
	}
	n, err := strconv.Atoi(val)
	if err != nil {
		return fallback, err
	}
	return n, nil
}

func fixedPageOffset(c *gin.Context, perPage int) (int, int) {
	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
	if page < 1 {
		page = 1
	}
	return page, (page - 1) * perPage
}

func parseUintAnyParam(c *gin.Context, params ...string) (uint, error) {
	var lastErr error
	for _, param := range params {
		if c.Param(param) == "" {
			continue
		}
		id, err := parseUintParam(c, param)
		if err == nil && id != 0 {
			return id, nil
		}
		return 0, err
	}
	return 0, lastErr
}

// parseAccountIDParam accepts both Chatwoot-style :account_id and older local
// tests/routes that still mount the account parameter as :id.
func parseAccountIDParam(c *gin.Context) uint {
	if id, err := parseUintParam(c, "account_id"); err == nil && id != 0 {
		return id
	}
	if id, err := parseUintParam(c, "id"); err == nil && id != 0 {
		return id
	}
	return 0
}

// getAccountID extracts account ID from the request.
// Priority: URL param account_id > X-Account-ID header > JWT claims account_id
func getAccountID(c *gin.Context) uint {
	// Try URL param — Chatwoot uses :account_id, GoChat routes use :account_id where possible
	if id, err := parseUintParam(c, "account_id"); err == nil && id != 0 {
		return id
	}
	// Try X-Account-ID header
	headerAccountID := c.GetHeader("X-Account-ID")
	if headerAccountID != "" {
		id, err := strconv.ParseUint(headerAccountID, 10, 32)
		if err == nil && id != 0 {
			return uint(id)
		}
	}
	// Fall back to JWT claims (set by AuthRequired middleware)
	if accountID, exists := c.Get("account_id"); exists {
		switch v := accountID.(type) {
		case uint:
			if v != 0 {
				return v
			}
		case float64:
			if v != 0 {
				return uint(v)
			}
		case int:
			if v != 0 {
				return uint(v)
			}
		}
	}
	return 0
}

// getRole extracts the current user's role from the Gin context.
// Returns the role string (e.g. "administrator", "agent") from auth middleware claims.
func getRole(c *gin.Context) string {
	if role, exists := c.Get("role"); exists {
		if s, ok := role.(string); ok {
			return s
		}
	}
	return ""
}

// getCustomRoleID extracts the current user's custom role ID from the Gin context.
func getCustomRoleID(c *gin.Context) uint {
	if id, exists := c.Get("custom_role_id"); exists {
		switch v := id.(type) {
		case uint:
			return v
		case float64:
			return uint(v)
		case int:
			return uint(v)
		}
	}
	return 0
}

// getUserID extracts the current user ID from the Gin context.
// Priority: JWT claims > X-User-ID header
func getUserID(c *gin.Context) uint {
	if userID, exists := c.Get("user_id"); exists {
		switch v := userID.(type) {
		case uint:
			return v
		case float64:
			return uint(v)
		case int:
			return uint(v)
		case string:
			n, err := strconv.ParseUint(v, 10, 32)
			if err == nil {
				return uint(n)
			}
		}
	}
	// Fallback: X-User-ID header
	headerUserID := c.GetHeader("X-User-ID")
	if headerUserID != "" {
		n, err := strconv.ParseUint(headerUserID, 10, 32)
		if err == nil {
			return uint(n)
		}
	}
	return 0
}

// getPage extracts page number from query params (default: 1).
func getPage(c *gin.Context) int {
	val := c.DefaultQuery("page", "1")
	n, err := strconv.Atoi(val)
	if err != nil || n < 1 {
		return 1
	}
	return n
}

// getPageSize extracts page size from query params (default: 25, max: 100).
func getPageSize(c *gin.Context) int {
	val := c.DefaultQuery("page_size", "25")
	n, err := strconv.Atoi(val)
	if err != nil || n < 1 {
		return 25
	}
	if n > 100 {
		return 100
	}
	return n
}