package handler

import (
	"context"
	"database/sql"
	"errors"
	"log/slog"
	"net/http"
	"strconv"

	cf "goflare/internal/cloudflare"
	"goflare/internal/database/queries"

	"github.com/labstack/echo/v4"
)

type RecordHandler struct {
	q *queries.Queries
}

func NewRecordHandler(q *queries.Queries) *RecordHandler {
	return &RecordHandler{q: q}
}

type recordRequest struct {
	ZoneID     int64  `json:"zone_id"`
	CfRecordID string `json:"cf_record_id"`
	Name       string `json:"name"`
	Type       string `json:"type"`
	Content    string `json:"content"`
	Proxied    bool   `json:"proxied"`
	IsStatic   bool   `json:"is_static"`
}

func boolToInt64(b bool) int64 {
	if b {
		return 1
	}
	return 0
}

// pushRecordToCloudflare updates the DNS record on Cloudflare to match the local record.
func (h *RecordHandler) pushRecordToCloudflare(ctx context.Context, record queries.Record) error {
	zone, err := h.q.GetZone(ctx, record.ZoneID)
	if err != nil {
		return err
	}
	return cf.UpdateDNSRecord(ctx, zone.ApiKey, zone.ZoneID, record.CfRecordID, cf.DNSRecord{
		Type:    record.Type,
		Name:    record.Name,
		Content: record.Content,
		Proxied: record.Proxied == 1,
		TTL:     1, // auto
	})
}

func (h *RecordHandler) List(c echo.Context) error {
	zoneIDStr := c.QueryParam("zone_id")

	if zoneIDStr != "" {
		zoneID, err := strconv.ParseInt(zoneIDStr, 10, 64)
		if err != nil {
			return c.JSON(http.StatusBadRequest, map[string]string{"error": "invalid zone_id"})
		}
		records, err := h.q.ListRecordsByZone(c.Request().Context(), zoneID)
		if err != nil {
			return c.JSON(http.StatusInternalServerError, map[string]string{"error": "failed to list records"})
		}
		if records == nil {
			records = []queries.ListRecordsByZoneRow{}
		}
		return c.JSON(http.StatusOK, records)
	}

	records, err := h.q.ListRecords(c.Request().Context())
	if err != nil {
		return c.JSON(http.StatusInternalServerError, map[string]string{"error": "failed to list records"})
	}
	if records == nil {
		records = []queries.ListRecordsRow{}
	}
	return c.JSON(http.StatusOK, records)
}

func (h *RecordHandler) Get(c echo.Context) error {
	id, err := strconv.ParseInt(c.Param("id"), 10, 64)
	if err != nil {
		return c.JSON(http.StatusBadRequest, map[string]string{"error": "invalid id"})
	}

	record, err := h.q.GetRecord(c.Request().Context(), id)
	if errors.Is(err, sql.ErrNoRows) {
		return c.JSON(http.StatusNotFound, map[string]string{"error": "record not found"})
	}
	if err != nil {
		return c.JSON(http.StatusInternalServerError, map[string]string{"error": "failed to get record"})
	}

	return c.JSON(http.StatusOK, record)
}

func (h *RecordHandler) Create(c echo.Context) error {
	var req recordRequest
	if err := c.Bind(&req); err != nil {
		return c.JSON(http.StatusBadRequest, map[string]string{"error": "invalid request body"})
	}
	if req.ZoneID == 0 || req.CfRecordID == "" || req.Name == "" || req.Content == "" {
		return c.JSON(http.StatusBadRequest, map[string]string{"error": "zone_id, cf_record_id, name, and content required"})
	}
	if req.Type == "" {
		req.Type = "A"
	}

	record, err := h.q.CreateRecord(c.Request().Context(), queries.CreateRecordParams{
		ZoneID:     req.ZoneID,
		CfRecordID: req.CfRecordID,
		Name:       req.Name,
		Type:       req.Type,
		Content:    req.Content,
		Proxied:    boolToInt64(req.Proxied),
		IsStatic:   boolToInt64(req.IsStatic),
	})
	if err != nil {
		return c.JSON(http.StatusInternalServerError, map[string]string{"error": "failed to create record"})
	}

	return c.JSON(http.StatusCreated, record)
}

func (h *RecordHandler) Update(c echo.Context) error {
	id, err := strconv.ParseInt(c.Param("id"), 10, 64)
	if err != nil {
		return c.JSON(http.StatusBadRequest, map[string]string{"error": "invalid id"})
	}

	var req recordRequest
	if err := c.Bind(&req); err != nil {
		return c.JSON(http.StatusBadRequest, map[string]string{"error": "invalid request body"})
	}
	if req.Name == "" || req.Content == "" {
		return c.JSON(http.StatusBadRequest, map[string]string{"error": "name and content required"})
	}
	if req.Type == "" {
		req.Type = "A"
	}

	ctx := c.Request().Context()
	record, err := h.q.UpdateRecord(ctx, queries.UpdateRecordParams{
		ID:       id,
		Name:     req.Name,
		Type:     req.Type,
		Content:  req.Content,
		Proxied:  boolToInt64(req.Proxied),
		IsStatic: boolToInt64(req.IsStatic),
	})
	if errors.Is(err, sql.ErrNoRows) {
		return c.JSON(http.StatusNotFound, map[string]string{"error": "record not found"})
	}
	if err != nil {
		return c.JSON(http.StatusInternalServerError, map[string]string{"error": "failed to update record"})
	}
	if err := h.pushRecordToCloudflare(ctx, record); err != nil {
		slog.Error("failed to update record on Cloudflare", "record_id", record.ID, "error", err)
		return c.JSON(http.StatusBadGateway, map[string]string{"error": "record updated locally but failed to update on Cloudflare: " + err.Error()})
	}

	return c.JSON(http.StatusOK, record)
}

func (h *RecordHandler) Delete(c echo.Context) error {
	id, err := strconv.ParseInt(c.Param("id"), 10, 64)
	if err != nil {
		return c.JSON(http.StatusBadRequest, map[string]string{"error": "invalid id"})
	}

	if err := h.q.DeleteRecord(c.Request().Context(), id); err != nil {
		return c.JSON(http.StatusInternalServerError, map[string]string{"error": "failed to delete record"})
	}

	return c.JSON(http.StatusOK, map[string]string{"message": "record deleted"})
}

type partialRecordRequest struct {
	Name     *string `json:"name"`
	Type     *string `json:"type"`
	Content  *string `json:"content"`
	Proxied  *bool   `json:"proxied"`
	IsStatic *bool   `json:"is_static"`
}

func (h *RecordHandler) PartialUpdate(c echo.Context) error {
	id, err := strconv.ParseInt(c.Param("id"), 10, 64)
	if err != nil {
		return c.JSON(http.StatusBadRequest, map[string]string{"error": "invalid id"})
	}

	var req partialRecordRequest
	if err := c.Bind(&req); err != nil {
		return c.JSON(http.StatusBadRequest, map[string]string{"error": "invalid request body"})
	}

	ctx := c.Request().Context()

	existing, err := h.q.GetRecord(ctx, id)
	if errors.Is(err, sql.ErrNoRows) {
		return c.JSON(http.StatusNotFound, map[string]string{"error": "record not found"})
	}
	if err != nil {
		return c.JSON(http.StatusInternalServerError, map[string]string{"error": "failed to get record"})
	}

	params := queries.UpdateRecordParams{
		ID:       id,
		Name:     existing.Name,
		Type:     existing.Type,
		Content:  existing.Content,
		Proxied:  existing.Proxied,
		IsStatic: existing.IsStatic,
	}
	if req.Name != nil {
		params.Name = *req.Name
	}
	if req.Type != nil {
		params.Type = *req.Type
	}
	if req.Content != nil {
		params.Content = *req.Content
	}
	if req.Proxied != nil {
		params.Proxied = boolToInt64(*req.Proxied)
	}
	if req.IsStatic != nil {
		params.IsStatic = boolToInt64(*req.IsStatic)
	}

	record, err := h.q.UpdateRecord(ctx, params)
	if err != nil {
		return c.JSON(http.StatusInternalServerError, map[string]string{"error": "failed to update record"})
	}
	if err := h.pushRecordToCloudflare(ctx, record); err != nil {
		slog.Error("failed to update record on Cloudflare", "record_id", record.ID, "error", err)
		return c.JSON(http.StatusBadGateway, map[string]string{"error": "record updated locally but failed to update on Cloudflare: " + err.Error()})
	}

	return c.JSON(http.StatusOK, record)
}

func (h *RecordHandler) Sync(c echo.Context) error {
	ctx := c.Request().Context()

	zones, err := h.q.ListZones(ctx)
	if err != nil {
		return c.JSON(http.StatusInternalServerError, map[string]string{"error": "failed to list zones"})
	}

	var synced int
	for _, zone := range zones {
		cfRecords, err := cf.ListDNSRecords(ctx, zone.ApiKey, zone.ZoneID)
		if err != nil {
			slog.Error("failed to fetch CF records", "zone", zone.Name, "error", err)
			continue
		}

		cfIDs := make(map[string]struct{}, len(cfRecords))
		for _, rec := range cfRecords {
			cfIDs[rec.ID] = struct{}{}

			var proxied int64
			if rec.Proxied {
				proxied = 1
			}

			_, err := h.q.UpsertRecord(ctx, queries.UpsertRecordParams{
				ZoneID:     zone.ID,
				CfRecordID: rec.ID,
				Name:       rec.Name,
				Type:       rec.Type,
				Content:    rec.Content,
				Proxied:    proxied,
				IsStatic:   1,
			})
			if err != nil {
				slog.Error("failed to upsert record", "name", rec.Name, "error", err)
				continue
			}
			synced++
		}

		localIDs, err := h.q.ListRecordCfIDsByZone(ctx, zone.ID)
		if err != nil {
			slog.Error("failed to list local record IDs", "zone", zone.Name, "error", err)
			continue
		}
		for _, localID := range localIDs {
			if _, exists := cfIDs[localID]; !exists {
				_ = h.q.DeleteRecordByCfID(ctx, queries.DeleteRecordByCfIDParams{
					ZoneID:     zone.ID,
					CfRecordID: localID,
				})
			}
		}
	}

	return c.JSON(http.StatusOK, map[string]int{"synced": synced})
}