package v1

import (
	"net/http"
	"strconv"

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

// AutoReplyRuleHandler handles Captain auto-reply rule REST API endpoints.
// Reference: M12 PRD §Captain AI — Auto-Reply Rules
type AutoReplyRuleHandler struct {
	svc *service.AutoReplyRuleService
}

// NewAutoReplyRuleHandler creates a new AutoReplyRuleHandler.
func NewAutoReplyRuleHandler(svc *service.AutoReplyRuleService) *AutoReplyRuleHandler {
	return &AutoReplyRuleHandler{svc: svc}
}

// Create creates a new auto-reply rule for an assistant.
// POST /api/v1/accounts/:account_id/captain/assistants/:assistant_id/auto_reply_rules
func (h *AutoReplyRuleHandler) Create(c *gin.Context) {
	accountID, err := strconv.ParseUint(c.Param("account_id"), 10, 64)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, "invalid_account_id", "Invalid account ID")
		return
	}

	var req service.CreateAutoReplyRuleRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, "invalid_request", err.Error())
		return
	}

	result, err := h.svc.CreateRule(c.Request.Context(), uint(accountID), &req)
	if err != nil {
		applogger.L().Errorf("AutoReplyRuleHandler.Create failed: %v", err)
		response.AbortWithStatusError(c, http.StatusUnprocessableEntity, "create_failed", "Failed to create auto-reply rule")
		return
	}

	response.Created(c, result)
}

// Get retrieves a single auto-reply rule.
// GET /api/v1/accounts/:account_id/captain/auto_reply_rules/:rule_id
func (h *AutoReplyRuleHandler) Get(c *gin.Context) {
	accountID, err := strconv.ParseUint(c.Param("account_id"), 10, 64)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, "invalid_account_id", "Invalid account ID")
		return
	}

	ruleID, err := strconv.ParseUint(c.Param("rule_id"), 10, 64)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, "invalid_rule_id", "Invalid rule ID")
		return
	}

	result, err := h.svc.GetRule(c.Request.Context(), uint(accountID), uint(ruleID))
	if err != nil {
		applogger.L().Errorf("AutoReplyRuleHandler.Get failed: %v", err)
		response.AbortWithStatusError(c, http.StatusNotFound, "not_found", "Auto-reply rule not found")
		return
	}

	response.OK(c, result)
}

// Update updates an existing auto-reply rule.
// PUT /api/v1/accounts/:account_id/captain/auto_reply_rules/:rule_id
func (h *AutoReplyRuleHandler) Update(c *gin.Context) {
	accountID, err := strconv.ParseUint(c.Param("account_id"), 10, 64)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, "invalid_account_id", "Invalid account ID")
		return
	}

	ruleID, err := strconv.ParseUint(c.Param("rule_id"), 10, 64)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, "invalid_rule_id", "Invalid rule ID")
		return
	}

	var req service.UpdateAutoReplyRuleRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, "invalid_request", err.Error())
		return
	}

	result, err := h.svc.UpdateRule(c.Request.Context(), uint(accountID), uint(ruleID), &req)
	if err != nil {
		applogger.L().Errorf("AutoReplyRuleHandler.Update failed: %v", err)
		response.AbortWithStatusError(c, http.StatusUnprocessableEntity, "update_failed", "Failed to update auto-reply rule")
		return
	}

	response.OK(c, result)
}

// Delete removes an auto-reply rule.
// DELETE /api/v1/accounts/:account_id/captain/auto_reply_rules/:rule_id
func (h *AutoReplyRuleHandler) Delete(c *gin.Context) {
	accountID, err := strconv.ParseUint(c.Param("account_id"), 10, 64)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, "invalid_account_id", "Invalid account ID")
		return
	}

	ruleID, err := strconv.ParseUint(c.Param("rule_id"), 10, 64)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, "invalid_rule_id", "Invalid rule ID")
		return
	}

	if err := h.svc.DeleteRule(c.Request.Context(), uint(accountID), uint(ruleID)); err != nil {
		applogger.L().Errorf("AutoReplyRuleHandler.Delete failed: %v", err)
		response.AbortWithStatusError(c, http.StatusUnprocessableEntity, "delete_failed", "Failed to delete auto-reply rule")
		return
	}

	response.NoContent(c)
}

// List returns auto-reply rules for an account, optionally filtered by assistant.
// GET /api/v1/accounts/:account_id/captain/auto_reply_rules
func (h *AutoReplyRuleHandler) List(c *gin.Context) {
	accountID, err := strconv.ParseUint(c.Param("account_id"), 10, 64)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, "invalid_account_id", "Invalid account ID")
		return
	}

	p := pagination.Parse(c)
	results, total, err := h.svc.ListRules(c.Request.Context(), uint(accountID), p.Offset, p.PerPage)
	if err != nil {
		applogger.L().Errorf("AutoReplyRuleHandler.List failed: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, "list_failed", "Failed to list auto-reply rules")
		return
	}

	response.OKWithMeta(c, results, p.Page, p.PerPage, total)
}

// Evaluate checks rules against a conversation context and returns the best match.
// POST /api/v1/accounts/:account_id/captain/auto_reply_rules/evaluate
func (h *AutoReplyRuleHandler) Evaluate(c *gin.Context) {
	accountID, _ := strconv.ParseUint(c.Param("account_id"), 10, 64)
	_ = uint(accountID) // scoped by account_id path param; will be used when EvaluateRules gains account-scoping

	var evalCtx service.AutoReplyEvaluationContext
	if err := c.ShouldBindJSON(&evalCtx); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, "invalid_request", err.Error())
		return
	}

	// Override account_id from path param (authoritative source)
	evalCtx.AccountID = uint(accountID)

	result, err := h.svc.EvaluateRules(c.Request.Context(), &evalCtx)
	if err != nil {
		applogger.L().Errorf("AutoReplyRuleHandler.Evaluate failed: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, "evaluate_failed", "Failed to evaluate auto-reply rules")
		return
	}

	response.OK(c, result)
}