package api

import (
	"encoding/json"
	"net/http"
	"strings"

	"crypto-miner-server/internal/erasure"
)

type ErasureSwarmHandler struct {
	awsSettings func() erasure.AWSSwarmSettings
	objectStore func() erasure.ShardObjectStore
}

func NewErasureSwarmHandler(awsSettings func() erasure.AWSSwarmSettings, objectStore func() erasure.ShardObjectStore) *ErasureSwarmHandler {
	return &ErasureSwarmHandler{awsSettings: awsSettings, objectStore: objectStore}
}

type erasureSwarmTestResponse struct {
	OK               bool   `json:"ok"`
	CredentialsReady bool   `json:"credentials_ready"`
	SigningReady     bool   `json:"signing_ready"`
	Error            string `json:"error,omitempty"`
	S3Bucket         string `json:"s3_bucket,omitempty"`
	CloudFrontDomain string `json:"cloudfront_domain,omitempty"`
}

func (h *ErasureSwarmHandler) PostTest(w http.ResponseWriter, r *http.Request) {
	cfg := h.cfg(r)
	resp := erasureSwarmTestResponse{S3Bucket: cfg.S3Bucket, CloudFrontDomain: cfg.CloudFrontDomain, CredentialsReady: cfg.CredentialsReady(), SigningReady: cfg.SigningReady()}
	if !cfg.Enabled() {
		resp.Error = "set aws_s3_shard_bucket and aws_cloudfront_domain"
		writeJSON(w, resp)
		return
	}
	if !cfg.CredentialsReady() {
		resp.Error = "set AF_AWS_ACCESS_KEY_ID and AF_AWS_SECRET_ACCESS_KEY"
		writeJSON(w, resp)
		return
	}
	if err := h.store().HeadBucket(r.Context(), cfg.S3Bucket); err != nil {
		resp.Error = err.Error()
		writeJSON(w, resp)
		return
	}
	resp.OK = true
	writeJSON(w, resp)
}

func (h *ErasureSwarmHandler) GetPolicyJSON(w http.ResponseWriter, r *http.Request) {
	cfg := h.cfg(r)
	bucket := strings.TrimSpace(r.URL.Query().Get("bucket"))
	if bucket == "" {
		bucket = cfg.S3Bucket
	}
	writeJSON(w, map[string]interface{}{
		"iam_policy":    erasure.MinimalIAMPolicyJSON(bucket),
		"bucket_policy": erasure.MinimalBucketPolicyJSON(bucket, r.URL.Query().Get("cloudfront_arn")),
		"env_keys":      []string{"AF_AWS_ACCESS_KEY_ID", "AF_AWS_SECRET_ACCESS_KEY", "AF_AWS_REGION", "AF_CLOUDFRONT_KEY_PAIR_ID", "AF_CLOUDFRONT_PRIVATE_KEY"},
	})
}

func (h *ErasureSwarmHandler) cfg(r *http.Request) erasure.AWSSwarmSettings {
	cfg := erasure.AWSSwarmSettings{}
	if h != nil && h.awsSettings != nil {
		cfg = h.awsSettings()
	}
	if r != nil && r.Method == http.MethodPost {
		var body struct {
			S3Bucket         string `json:"s3_bucket"`
			CloudFrontDomain string `json:"cloudfront_domain"`
		}
		if json.NewDecoder(r.Body).Decode(&body) == nil {
			if v := strings.TrimSpace(body.S3Bucket); v != "" {
				cfg.S3Bucket = v
			}
			if v := strings.TrimSpace(body.CloudFrontDomain); v != "" {
				cfg.CloudFrontDomain = v
			}
		}
	}
	return erasure.HydrateAWSSwarmFromEnv(cfg)
}

func (h *ErasureSwarmHandler) store() erasure.ShardObjectStore {
	if h != nil && h.objectStore != nil {
		return h.objectStore()
	}
	cfg := erasure.AWSSwarmSettings{}
	if h != nil && h.awsSettings != nil {
		cfg = erasure.HydrateAWSSwarmFromEnv(h.awsSettings())
	}
	return &erasure.S3HTTPStore{Settings: cfg}
}