package v1

import (
	"errors"
	"net/http"

	"github.com/gin-gonic/gin"
	"github.com/gochat/gochat/internal/model"
	"github.com/gochat/gochat/internal/service"
	applogger "github.com/gochat/gochat/pkg/logger"
	"github.com/gochat/gochat/pkg/response"
)

// CaptainCustomToolHandler handles CaptainCustomTool REST API endpoints.
// Reference: Chatwoot enterprise/app/controllers/api/v1/captain/custom_tools_controller.rb
type CaptainCustomToolHandler struct {
	svc *service.CaptainCustomToolService
}

// NewCaptainCustomToolHandler creates a new CaptainCustomToolHandler.
func NewCaptainCustomToolHandler(svc *service.CaptainCustomToolService) *CaptainCustomToolHandler {
	return &CaptainCustomToolHandler{svc: svc}
}

// Create creates a new custom tool.
// POST /api/v1/accounts/:account_id/captain_custom_tools
func (h *CaptainCustomToolHandler) Create(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return
	}
	if !h.ensureCustomToolsEnabled(c, accountID) {
		return
	}

	var req service.CreateCustomToolRequest
	if err := bindNestedJSONPayload(c, "custom_tool", &req); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, err.Error())
		return
	}

	tool, err := h.svc.Create(c.Request.Context(), accountID, &req)
	if err != nil {
		applogger.L().Errorf("Create captain custom tool: %v", err)
		if errors.Is(err, service.ErrCaptainCustomToolLimitExceeded) {
			c.JSON(http.StatusUnprocessableEntity, gin.H{"error": service.ErrCaptainCustomToolLimitExceeded.Error()})
			return
		}
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to create custom tool")
		return
	}

	c.JSON(http.StatusOK, captainCustomToolPayload(tool))
}

// Get retrieves a custom tool by ID.
// GET /api/v1/accounts/:account_id/captain_custom_tools/:id
func (h *CaptainCustomToolHandler) Get(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return
	}
	if !h.ensureCustomToolsEnabled(c, accountID) {
		return
	}
	id, err := parseUintAnyParam(c, "tool_id", "id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid id")
		return
	}

	tool, err := h.svc.GetByAccount(c.Request.Context(), accountID, id)
	if err != nil {
		applogger.L().Errorf("Get captain custom tool: %v", err)
		response.AbortWithStatusError(c, http.StatusNotFound, response.ErrNotFound, "custom tool not found")
		return
	}

	c.JSON(http.StatusOK, captainCustomToolPayload(tool))
}

// Update updates an existing custom tool.
// PUT /api/v1/accounts/:account_id/captain_custom_tools/:id
func (h *CaptainCustomToolHandler) Update(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return
	}
	if !h.ensureCustomToolsEnabled(c, accountID) {
		return
	}
	id, err := parseUintAnyParam(c, "tool_id", "id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid id")
		return
	}

	var req service.UpdateCustomToolRequest
	if err := bindNestedJSONPayload(c, "custom_tool", &req); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, err.Error())
		return
	}

	tool, err := h.svc.UpdateByAccount(c.Request.Context(), accountID, id, &req)
	if err != nil {
		applogger.L().Errorf("Update captain custom tool: %v", err)
		handleServiceError(c, err)
		return
	}

	c.JSON(http.StatusOK, captainCustomToolPayload(tool))
}

// Delete deletes a custom tool.
// DELETE /api/v1/accounts/:account_id/captain_custom_tools/:id
func (h *CaptainCustomToolHandler) Delete(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return
	}
	if !h.ensureCustomToolsEnabled(c, accountID) {
		return
	}
	id, err := parseUintAnyParam(c, "tool_id", "id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid id")
		return
	}

	if err := h.svc.DeleteByAccount(c.Request.Context(), accountID, id); err != nil {
		applogger.L().Errorf("Delete captain custom tool: %v", err)
		response.AbortWithStatusError(c, captainAssistantErrorStatus(err), response.ErrInternal, "failed to delete custom tool")
		return
	}

	response.NoContent(c)
}

// List retrieves custom tools for an account.
// GET /api/v1/accounts/:account_id/captain_custom_tools
func (h *CaptainCustomToolHandler) List(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return
	}
	if !h.ensureCustomToolsEnabled(c, accountID) {
		return
	}

	tools, count, err := h.svc.List(c.Request.Context(), accountID, 0, 1000)
	if err != nil {
		applogger.L().Errorf("List captain custom tools: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to list custom tools")
		return
	}

	payload := make([]gin.H, 0, len(tools))
	for i := range tools {
		payload = append(payload, captainCustomToolPayload(&tools[i]))
	}
	c.JSON(http.StatusOK, gin.H{"payload": payload, "meta": gin.H{"total_count": count, "page": 1}})
}

// ExecuteTool calls the external HTTP endpoint of a custom tool.
// POST /api/v1/accounts/:account_id/captain_custom_tools/:id/execute
func (h *CaptainCustomToolHandler) ExecuteTool(c *gin.Context) {
	id, err := parseUintAnyParam(c, "tool_id", "id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid id")
		return
	}

	var params map[string]interface{}
	if err := c.ShouldBindJSON(&params); err != nil {
		// Empty body is acceptable (use nil params)
		params = nil
	}

	result, err := h.svc.ExecuteTool(c.Request.Context(), id, params)
	if err != nil {
		applogger.L().Errorf("ExecuteTool: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to execute tool")
		return
	}

	response.OK(c, result)
}

// TestTool tests a custom tool with given parameters.
// POST /api/v1/accounts/:account_id/captain/custom_tools/test
func (h *CaptainCustomToolHandler) TestTool(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return
	}
	if !h.ensureCustomToolsEnabled(c, accountID) {
		return
	}

	var req service.TestToolRequest
	if err := bindNestedJSONPayload(c, "custom_tool", &req); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, err.Error())
		return
	}

	result, err := h.svc.TestTool(c.Request.Context(), accountID, &req)
	if err != nil {
		applogger.L().Errorf("TestTool: %v", err)
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, result)
}

func (h *CaptainCustomToolHandler) ensureCustomToolsEnabled(c *gin.Context, accountID uint) bool {
	if h.svc.CustomToolsEnabled(c.Request.Context(), accountID) {
		return true
	}
	c.JSON(http.StatusForbidden, gin.H{"error": "Custom tools are not enabled for this account"})
	return false
}

func captainCustomToolPayload(tool *model.CaptainCustomTool) gin.H {
	return gin.H{
		"id":                tool.ID,
		"slug":              tool.Slug,
		"title":             tool.Title,
		"description":       tool.Description,
		"endpoint_url":      tool.EndpointURL,
		"http_method":       tool.HTTPMethod,
		"request_template":  tool.RequestTemplate,
		"response_template": tool.ResponseTemplate,
		"auth_type":         tool.AuthType,
		"auth_config":       rawJSONValue(tool.AuthConfig),
		"param_schema":      rawJSONValue(tool.ParamSchema),
		"enabled":           tool.Enabled,
		"account_id":        tool.AccountID,
		"created_at":        tool.CreatedAt.Unix(),
		"updated_at":        tool.UpdatedAt.Unix(),
	}
}