package forge

import (
	"context"
	"iter"

	"dappco.re/go/core/forge/types"
)

// MilestoneListOptions controls filtering for repository milestone listings.
//
// Usage:
//
//	opts := forge.MilestoneListOptions{State: "open"}
type MilestoneListOptions struct {
	State string
	Name  string
}

// String returns a safe summary of the milestone filters.
func (o MilestoneListOptions) String() string {
	return optionString("forge.MilestoneListOptions", "state", o.State, "name", o.Name)
}

// GoString returns a safe Go-syntax summary of the milestone filters.
func (o MilestoneListOptions) GoString() string { return o.String() }

func (o MilestoneListOptions) queryParams() map[string]string {
	query := make(map[string]string, 2)
	if o.State != "" {
		query["state"] = o.State
	}
	if o.Name != "" {
		query["name"] = o.Name
	}
	if len(query) == 0 {
		return nil
	}
	return query
}

// MilestoneService handles repository milestones.
//
// Usage:
//
//	f := forge.NewForge("https://forge.lthn.ai", "token")
//	_, err := f.Milestones.ListAll(ctx, forge.Params{"owner": "core", "repo": "go-forge"})
type MilestoneService struct {
	client *Client
}

func newMilestoneService(c *Client) *MilestoneService {
	return &MilestoneService{client: c}
}

// List returns a single page of milestones for a repository.
func (s *MilestoneService) List(ctx context.Context, params Params, opts ListOptions, filters ...MilestoneListOptions) (*PagedResult[types.Milestone], error) {
	path := ResolvePath("/api/v1/repos/{owner}/{repo}/milestones", params)
	return ListPage[types.Milestone](ctx, s.client, path, milestoneQuery(filters...), opts)
}

// Iter returns an iterator over all milestones for a repository.
func (s *MilestoneService) Iter(ctx context.Context, params Params, filters ...MilestoneListOptions) iter.Seq2[types.Milestone, error] {
	path := ResolvePath("/api/v1/repos/{owner}/{repo}/milestones", params)
	return ListIter[types.Milestone](ctx, s.client, path, milestoneQuery(filters...))
}

// ListAll returns all milestones for a repository.
func (s *MilestoneService) ListAll(ctx context.Context, params Params, filters ...MilestoneListOptions) ([]types.Milestone, error) {
	path := ResolvePath("/api/v1/repos/{owner}/{repo}/milestones", params)
	return ListAll[types.Milestone](ctx, s.client, path, milestoneQuery(filters...))
}

// Get returns a single milestone by ID.
func (s *MilestoneService) Get(ctx context.Context, owner, repo string, id int64) (*types.Milestone, error) {
	path := ResolvePath("/api/v1/repos/{owner}/{repo}/milestones/{id}", pathParams("owner", owner, "repo", repo, "id", int64String(id)))
	var out types.Milestone
	if err := s.client.Get(ctx, path, &out); err != nil {
		return nil, err
	}
	return &out, nil
}

// Create creates a new milestone.
func (s *MilestoneService) Create(ctx context.Context, owner, repo string, opts *types.CreateMilestoneOption) (*types.Milestone, error) {
	path := ResolvePath("/api/v1/repos/{owner}/{repo}/milestones", pathParams("owner", owner, "repo", repo))
	var out types.Milestone
	if err := s.client.Post(ctx, path, opts, &out); err != nil {
		return nil, err
	}
	return &out, nil
}

// Edit updates an existing milestone.
func (s *MilestoneService) Edit(ctx context.Context, owner, repo string, id int64, opts *types.EditMilestoneOption) (*types.Milestone, error) {
	path := ResolvePath("/api/v1/repos/{owner}/{repo}/milestones/{id}", pathParams("owner", owner, "repo", repo, "id", int64String(id)))
	var out types.Milestone
	if err := s.client.Patch(ctx, path, opts, &out); err != nil {
		return nil, err
	}
	return &out, nil
}

// Delete removes a milestone.
func (s *MilestoneService) Delete(ctx context.Context, owner, repo string, id int64) error {
	path := ResolvePath("/api/v1/repos/{owner}/{repo}/milestones/{id}", pathParams("owner", owner, "repo", repo, "id", int64String(id)))
	return s.client.Delete(ctx, path)
}

func milestoneQuery(filters ...MilestoneListOptions) map[string]string {
	if len(filters) == 0 {
		return nil
	}

	query := make(map[string]string, 2)
	for _, filter := range filters {
		for key, value := range filter.queryParams() {
			query[key] = value
		}
	}
	if len(query) == 0 {
		return nil
	}
	return query
}