// Package officeconvertclient provides typed Connect RPC helpers for conversions.
package officeconvertclient

import (
	"context"
	"errors"
	"net/http"
	"time"

	"connectrpc.com/connect"
	officeconvertapiv1 "github.com/end/officeconvert/gen/go/officeconvertapi/v1"
	"github.com/end/officeconvert/gen/go/officeconvertapi/v1/officeconvertapiv1connect"
)

const defaultPollInterval = 2 * time.Second

// Client wraps the generated Connect client with orchestration-focused helpers.
type Client struct {
	rpc          officeconvertapiv1connect.ConversionServiceClient
	httpClient   *http.Client
	baseURL      string
	pollInterval time.Duration
}

// NewClient creates a new typed Officeconvert client.
func NewClient(baseURL string, httpClient *http.Client, options ...connect.ClientOption) *Client {
	if httpClient == nil {
		httpClient = http.DefaultClient
	}
	return &Client{
		rpc:          officeconvertapiv1connect.NewConversionServiceClient(httpClient, baseURL, options...),
		httpClient:   httpClient,
		baseURL:      baseURL,
		pollInterval: defaultPollInterval,
	}
}

// SetPollInterval configures the polling cadence used by WaitForCompletion.
func (c *Client) SetPollInterval(interval time.Duration) {
	if interval > 0 {
		c.pollInterval = interval
	}
}

// CreateConversion starts a conversion session and returns upload metadata.
func (c *Client) CreateConversion(
	ctx context.Context,
	sourceFilename string,
) (*officeconvertapiv1.CreateConversionResponse, error) {
	req := connect.NewRequest(&officeconvertapiv1.CreateConversionRequest{
		SourceFilename: sourceFilename,
	})
	res, err := c.rpc.CreateConversion(ctx, req)
	if err != nil {
		return nil, err
	}
	return res.Msg, nil
}

// StartConversion signals that upload is complete and conversion can begin.
func (c *Client) StartConversion(
	ctx context.Context,
	conversionID string,
) (*officeconvertapiv1.StartConversionResponse, error) {
	req := connect.NewRequest(&officeconvertapiv1.StartConversionRequest{
		ConversionId: conversionID,
	})
	res, err := c.rpc.StartConversion(ctx, req)
	if err != nil {
		return nil, err
	}
	return res.Msg, nil
}

// GetConversionStatus returns the latest status for a conversion session.
func (c *Client) GetConversionStatus(
	ctx context.Context,
	conversionID string,
) (*officeconvertapiv1.GetConversionStatusResponse, error) {
	req := connect.NewRequest(&officeconvertapiv1.GetConversionStatusRequest{
		ConversionId: conversionID,
	})
	res, err := c.rpc.GetConversionStatus(ctx, req)
	if err != nil {
		return nil, err
	}
	return res.Msg, nil
}

// GetSlideDeck retrieves the final converted deck response.
func (c *Client) GetSlideDeck(
	ctx context.Context,
	conversionID string,
) (*officeconvertapiv1.GetSlideDeckResponse, error) {
	req := connect.NewRequest(&officeconvertapiv1.GetSlideDeckRequest{
		ConversionId: conversionID,
	})
	res, err := c.rpc.GetSlideDeck(ctx, req)
	if err != nil {
		return nil, err
	}
	return res.Msg, nil
}

// DeleteConversion triggers immediate resource cleanup for a session.
func (c *Client) DeleteConversion(
	ctx context.Context,
	conversionID string,
) (*officeconvertapiv1.DeleteConversionResponse, error) {
	req := connect.NewRequest(&officeconvertapiv1.DeleteConversionRequest{
		ConversionId: conversionID,
	})
	res, err := c.rpc.DeleteConversion(ctx, req)
	if err != nil {
		return nil, err
	}
	return res.Msg, nil
}

// WaitForCompletion polls status until terminal completion or context cancellation.
func (c *Client) WaitForCompletion(
	ctx context.Context,
	conversionID string,
) (*officeconvertapiv1.GetConversionStatusResponse, error) {
	ticker := time.NewTicker(c.pollInterval)
	defer ticker.Stop()

	for {
		status, err := c.GetConversionStatus(ctx, conversionID)
		if err != nil {
			return nil, err
		}

		switch status.Status {
		case officeconvertapiv1.ConversionStatus_CONVERSION_STATUS_SUCCEEDED:
			return status, nil
		case officeconvertapiv1.ConversionStatus_CONVERSION_STATUS_FAILED:
			return nil, errors.New(status.ErrorMessage)
		}

		select {
		case <-ctx.Done():
			return nil, ctx.Err()
		case <-ticker.C:
		}
	}
}