package issue

import (
	"context"
	"fmt"

	"gitea.com/gitea/gitea-mcp/pkg/gitea"
	"gitea.com/gitea/gitea-mcp/pkg/log"
	"gitea.com/gitea/gitea-mcp/pkg/params"
	"gitea.com/gitea/gitea-mcp/pkg/to"
	"gitea.com/gitea/gitea-mcp/pkg/tool"

	gitea_sdk "code.gitea.io/sdk/gitea"
	"github.com/mark3labs/mcp-go/mcp"
	"github.com/mark3labs/mcp-go/server"
)

var Tool = tool.New()

const (
	ListRepoIssuesToolName = "list_issues"
	IssueReadToolName      = "issue_read"
	IssueWriteToolName     = "issue_write"
)

var (
	ListRepoIssuesTool = mcp.NewTool(
		ListRepoIssuesToolName,
		mcp.WithDescription("List repository issues"),
		mcp.WithString("owner", mcp.Required(), mcp.Description("repository owner")),
		mcp.WithString("repo", mcp.Required(), mcp.Description("repository name")),
		mcp.WithString("state", mcp.Description("issue state"), mcp.DefaultString("all")),
		mcp.WithNumber("page", mcp.Description("page number"), mcp.DefaultNumber(1)),
		mcp.WithNumber("perPage", mcp.Description("results per page"), mcp.DefaultNumber(30)),
	)

	IssueReadTool = mcp.NewTool(
		IssueReadToolName,
		mcp.WithDescription("Get information about a specific issue. Use method 'get' for issue details, 'get_comments' for issue comments, 'get_labels' for issue labels."),
		mcp.WithString("method", mcp.Required(), mcp.Description("operation to perform"), mcp.Enum("get", "get_comments", "get_labels")),
		mcp.WithString("owner", mcp.Required(), mcp.Description("repository owner")),
		mcp.WithString("repo", mcp.Required(), mcp.Description("repository name")),
		mcp.WithNumber("index", mcp.Required(), mcp.Description("repository issue index")),
	)

	IssueWriteTool = mcp.NewTool(
		IssueWriteToolName,
		mcp.WithDescription("Create or update issues and comments, manage labels. Use method 'create' to create an issue, 'update' to edit, 'add_comment'/'edit_comment' for comments, 'add_labels'/'remove_label'/'replace_labels'/'clear_labels' for label management."),
		mcp.WithString("method", mcp.Required(), mcp.Description("operation to perform"), mcp.Enum("create", "update", "add_comment", "edit_comment", "add_labels", "remove_label", "replace_labels", "clear_labels")),
		mcp.WithString("owner", mcp.Required(), mcp.Description("repository owner")),
		mcp.WithString("repo", mcp.Required(), mcp.Description("repository name")),
		mcp.WithNumber("index", mcp.Description("issue index (required for all methods except 'create')")),
		mcp.WithString("title", mcp.Description("issue title (required for 'create')")),
		mcp.WithString("body", mcp.Description("issue/comment body (required for 'create', 'add_comment', 'edit_comment')")),
		mcp.WithArray("assignees", mcp.Description("usernames to assign (for 'create', 'update')"), mcp.Items(map[string]any{"type": "string"})),
		mcp.WithNumber("milestone", mcp.Description("milestone number (for 'create', 'update')")),
		mcp.WithString("state", mcp.Description("issue state, one of open, closed, all (for 'update')")),
		mcp.WithNumber("commentID", mcp.Description("id of issue comment (required for 'edit_comment')")),
		mcp.WithArray("labels", mcp.Description("array of label IDs (for 'add_labels', 'replace_labels')"), mcp.Items(map[string]any{"type": "number"})),
		mcp.WithNumber("label_id", mcp.Description("label ID to remove (required for 'remove_label')")),
	)
)

func init() {
	Tool.RegisterRead(server.ServerTool{
		Tool:    ListRepoIssuesTool,
		Handler: listRepoIssuesFn,
	})
	Tool.RegisterRead(server.ServerTool{
		Tool:    IssueReadTool,
		Handler: issueReadFn,
	})
	Tool.RegisterWrite(server.ServerTool{
		Tool:    IssueWriteTool,
		Handler: issueWriteFn,
	})
}

func issueReadFn(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallToolResult, error) {
	args := req.GetArguments()
	method, err := params.GetString(args, "method")
	if err != nil {
		return to.ErrorResult(err)
	}
	switch method {
	case "get":
		return getIssueByIndexFn(ctx, req)
	case "get_comments":
		return getIssueCommentsByIndexFn(ctx, req)
	case "get_labels":
		return getIssueLabelsFn(ctx, req)
	default:
		return to.ErrorResult(fmt.Errorf("unknown method: %s", method))
	}
}

func issueWriteFn(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallToolResult, error) {
	args := req.GetArguments()
	method, err := params.GetString(args, "method")
	if err != nil {
		return to.ErrorResult(err)
	}
	switch method {
	case "create":
		return createIssueFn(ctx, req)
	case "update":
		return editIssueFn(ctx, req)
	case "add_comment":
		return createIssueCommentFn(ctx, req)
	case "edit_comment":
		return editIssueCommentFn(ctx, req)
	case "add_labels":
		return addIssueLabelsFn(ctx, req)
	case "remove_label":
		return removeIssueLabelFn(ctx, req)
	case "replace_labels":
		return replaceIssueLabelsFn(ctx, req)
	case "clear_labels":
		return clearIssueLabelsFn(ctx, req)
	default:
		return to.ErrorResult(fmt.Errorf("unknown method: %s", method))
	}
}

func getIssueByIndexFn(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallToolResult, error) {
	log.Debugf("Called getIssueByIndexFn")
	owner, err := params.GetString(req.GetArguments(), "owner")
	if err != nil {
		return to.ErrorResult(err)
	}
	repo, err := params.GetString(req.GetArguments(), "repo")
	if err != nil {
		return to.ErrorResult(err)
	}
	index, err := params.GetIndex(req.GetArguments(), "index")
	if err != nil {
		return to.ErrorResult(err)
	}
	client, err := gitea.ClientFromContext(ctx)
	if err != nil {
		return to.ErrorResult(fmt.Errorf("get gitea client err: %v", err))
	}
	issue, _, err := client.GetIssue(owner, repo, index)
	if err != nil {
		return to.ErrorResult(fmt.Errorf("get %v/%v/issue/%v err: %v", owner, repo, index, err))
	}

	return to.TextResult(slimIssue(issue))
}

func listRepoIssuesFn(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallToolResult, error) {
	log.Debugf("Called ListIssuesFn")
	owner, err := params.GetString(req.GetArguments(), "owner")
	if err != nil {
		return to.ErrorResult(err)
	}
	repo, err := params.GetString(req.GetArguments(), "repo")
	if err != nil {
		return to.ErrorResult(err)
	}
	state, ok := req.GetArguments()["state"].(string)
	if !ok {
		state = "all"
	}
	page, pageSize := params.GetPagination(req.GetArguments(), 30)
	opt := gitea_sdk.ListIssueOption{
		State: gitea_sdk.StateType(state),
		ListOptions: gitea_sdk.ListOptions{
			Page:     page,
			PageSize: pageSize,
		},
	}
	client, err := gitea.ClientFromContext(ctx)
	if err != nil {
		return to.ErrorResult(fmt.Errorf("get gitea client err: %v", err))
	}
	issues, _, err := client.ListRepoIssues(owner, repo, opt)
	if err != nil {
		return to.ErrorResult(fmt.Errorf("get %v/%v/issues err: %v", owner, repo, err))
	}
	return to.TextResult(slimIssues(issues))
}

func createIssueFn(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallToolResult, error) {
	log.Debugf("Called createIssueFn")
	owner, err := params.GetString(req.GetArguments(), "owner")
	if err != nil {
		return to.ErrorResult(err)
	}
	repo, err := params.GetString(req.GetArguments(), "repo")
	if err != nil {
		return to.ErrorResult(err)
	}
	title, err := params.GetString(req.GetArguments(), "title")
	if err != nil {
		return to.ErrorResult(err)
	}
	body, err := params.GetString(req.GetArguments(), "body")
	if err != nil {
		return to.ErrorResult(err)
	}
	client, err := gitea.ClientFromContext(ctx)
	if err != nil {
		return to.ErrorResult(fmt.Errorf("get gitea client err: %v", err))
	}
	opt := gitea_sdk.CreateIssueOption{
		Title: title,
		Body:  body,
	}
	opt.Assignees = params.GetStringSlice(req.GetArguments(), "assignees")
	if val, exists := req.GetArguments()["milestone"]; exists {
		if milestone, ok := params.ToInt64(val); ok {
			opt.Milestone = milestone
		}
	}
	issue, _, err := client.CreateIssue(owner, repo, opt)
	if err != nil {
		return to.ErrorResult(fmt.Errorf("create %v/%v/issue err: %v", owner, repo, err))
	}

	return to.TextResult(slimIssue(issue))
}

func createIssueCommentFn(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallToolResult, error) {
	log.Debugf("Called createIssueCommentFn")
	owner, err := params.GetString(req.GetArguments(), "owner")
	if err != nil {
		return to.ErrorResult(err)
	}
	repo, err := params.GetString(req.GetArguments(), "repo")
	if err != nil {
		return to.ErrorResult(err)
	}
	index, err := params.GetIndex(req.GetArguments(), "index")
	if err != nil {
		return to.ErrorResult(err)
	}
	body, err := params.GetString(req.GetArguments(), "body")
	if err != nil {
		return to.ErrorResult(err)
	}
	opt := gitea_sdk.CreateIssueCommentOption{
		Body: body,
	}
	client, err := gitea.ClientFromContext(ctx)
	if err != nil {
		return to.ErrorResult(fmt.Errorf("get gitea client err: %v", err))
	}
	issueComment, _, err := client.CreateIssueComment(owner, repo, index, opt)
	if err != nil {
		return to.ErrorResult(fmt.Errorf("create %v/%v/issue/%v/comment err: %v", owner, repo, index, err))
	}

	return to.TextResult(slimComment(issueComment))
}

func editIssueFn(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallToolResult, error) {
	log.Debugf("Called editIssueFn")
	owner, err := params.GetString(req.GetArguments(), "owner")
	if err != nil {
		return to.ErrorResult(err)
	}
	repo, err := params.GetString(req.GetArguments(), "repo")
	if err != nil {
		return to.ErrorResult(err)
	}
	index, err := params.GetIndex(req.GetArguments(), "index")
	if err != nil {
		return to.ErrorResult(err)
	}

	opt := gitea_sdk.EditIssueOption{}

	title, ok := req.GetArguments()["title"].(string)
	if ok {
		opt.Title = title
	}
	body, ok := req.GetArguments()["body"].(string)
	if ok {
		opt.Body = new(body)
	}
	opt.Assignees = params.GetStringSlice(req.GetArguments(), "assignees")
	if val, exists := req.GetArguments()["milestone"]; exists {
		if milestone, ok := params.ToInt64(val); ok {
			opt.Milestone = new(milestone)
		}
	}
	state, ok := req.GetArguments()["state"].(string)
	if ok {
		opt.State = new(gitea_sdk.StateType(state))
	}

	client, err := gitea.ClientFromContext(ctx)
	if err != nil {
		return to.ErrorResult(fmt.Errorf("get gitea client err: %v", err))
	}
	issue, _, err := client.EditIssue(owner, repo, index, opt)
	if err != nil {
		return to.ErrorResult(fmt.Errorf("edit %v/%v/issue/%v err: %v", owner, repo, index, err))
	}

	return to.TextResult(slimIssue(issue))
}

func editIssueCommentFn(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallToolResult, error) {
	log.Debugf("Called editIssueCommentFn")
	owner, err := params.GetString(req.GetArguments(), "owner")
	if err != nil {
		return to.ErrorResult(err)
	}
	repo, err := params.GetString(req.GetArguments(), "repo")
	if err != nil {
		return to.ErrorResult(err)
	}
	commentID, err := params.GetIndex(req.GetArguments(), "commentID")
	if err != nil {
		return to.ErrorResult(err)
	}
	body, err := params.GetString(req.GetArguments(), "body")
	if err != nil {
		return to.ErrorResult(err)
	}
	opt := gitea_sdk.EditIssueCommentOption{
		Body: body,
	}
	client, err := gitea.ClientFromContext(ctx)
	if err != nil {
		return to.ErrorResult(fmt.Errorf("get gitea client err: %v", err))
	}
	issueComment, _, err := client.EditIssueComment(owner, repo, commentID, opt)
	if err != nil {
		return to.ErrorResult(fmt.Errorf("edit %v/%v/issues/comments/%v err: %v", owner, repo, commentID, err))
	}

	return to.TextResult(slimComment(issueComment))
}

func getIssueCommentsByIndexFn(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallToolResult, error) {
	log.Debugf("Called getIssueCommentsByIndexFn")
	owner, err := params.GetString(req.GetArguments(), "owner")
	if err != nil {
		return to.ErrorResult(err)
	}
	repo, err := params.GetString(req.GetArguments(), "repo")
	if err != nil {
		return to.ErrorResult(err)
	}
	index, err := params.GetIndex(req.GetArguments(), "index")
	if err != nil {
		return to.ErrorResult(err)
	}
	opt := gitea_sdk.ListIssueCommentOptions{}
	client, err := gitea.ClientFromContext(ctx)
	if err != nil {
		return to.ErrorResult(fmt.Errorf("get gitea client err: %v", err))
	}
	issue, _, err := client.ListIssueComments(owner, repo, index, opt)
	if err != nil {
		return to.ErrorResult(fmt.Errorf("get %v/%v/issues/%v/comments err: %v", owner, repo, index, err))
	}

	return to.TextResult(slimComments(issue))
}

func getIssueLabelsFn(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallToolResult, error) {
	log.Debugf("Called getIssueLabelsFn")
	owner, err := params.GetString(req.GetArguments(), "owner")
	if err != nil {
		return to.ErrorResult(err)
	}
	repo, err := params.GetString(req.GetArguments(), "repo")
	if err != nil {
		return to.ErrorResult(err)
	}
	index, err := params.GetIndex(req.GetArguments(), "index")
	if err != nil {
		return to.ErrorResult(err)
	}

	client, err := gitea.ClientFromContext(ctx)
	if err != nil {
		return to.ErrorResult(fmt.Errorf("get gitea client err: %v", err))
	}
	labels, _, err := client.GetIssueLabels(owner, repo, index, gitea_sdk.ListLabelsOptions{})
	if err != nil {
		return to.ErrorResult(fmt.Errorf("get %v/%v/issues/%v/labels err: %v", owner, repo, index, err))
	}
	return to.TextResult(slimLabels(labels))
}

// Issue label operations (moved from label package)

func addIssueLabelsFn(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallToolResult, error) {
	log.Debugf("Called addIssueLabelsFn")
	owner, err := params.GetString(req.GetArguments(), "owner")
	if err != nil {
		return to.ErrorResult(err)
	}
	repo, err := params.GetString(req.GetArguments(), "repo")
	if err != nil {
		return to.ErrorResult(err)
	}
	index, err := params.GetIndex(req.GetArguments(), "index")
	if err != nil {
		return to.ErrorResult(err)
	}
	labels, err := params.GetInt64Slice(req.GetArguments(), "labels")
	if err != nil {
		return to.ErrorResult(err)
	}

	client, err := gitea.ClientFromContext(ctx)
	if err != nil {
		return to.ErrorResult(fmt.Errorf("get gitea client err: %v", err))
	}
	issueLabels, _, err := client.AddIssueLabels(owner, repo, index, gitea_sdk.IssueLabelsOption{Labels: labels})
	if err != nil {
		return to.ErrorResult(fmt.Errorf("add labels to %v/%v/issue/%v err: %v", owner, repo, index, err))
	}
	return to.TextResult(slimLabels(issueLabels))
}

func replaceIssueLabelsFn(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallToolResult, error) {
	log.Debugf("Called replaceIssueLabelsFn")
	owner, err := params.GetString(req.GetArguments(), "owner")
	if err != nil {
		return to.ErrorResult(err)
	}
	repo, err := params.GetString(req.GetArguments(), "repo")
	if err != nil {
		return to.ErrorResult(err)
	}
	index, err := params.GetIndex(req.GetArguments(), "index")
	if err != nil {
		return to.ErrorResult(err)
	}
	labels, err := params.GetInt64Slice(req.GetArguments(), "labels")
	if err != nil {
		return to.ErrorResult(err)
	}

	client, err := gitea.ClientFromContext(ctx)
	if err != nil {
		return to.ErrorResult(fmt.Errorf("get gitea client err: %v", err))
	}
	issueLabels, _, err := client.ReplaceIssueLabels(owner, repo, index, gitea_sdk.IssueLabelsOption{Labels: labels})
	if err != nil {
		return to.ErrorResult(fmt.Errorf("replace labels on %v/%v/issue/%v err: %v", owner, repo, index, err))
	}
	return to.TextResult(slimLabels(issueLabels))
}

func clearIssueLabelsFn(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallToolResult, error) {
	log.Debugf("Called clearIssueLabelsFn")
	owner, err := params.GetString(req.GetArguments(), "owner")
	if err != nil {
		return to.ErrorResult(err)
	}
	repo, err := params.GetString(req.GetArguments(), "repo")
	if err != nil {
		return to.ErrorResult(err)
	}
	index, err := params.GetIndex(req.GetArguments(), "index")
	if err != nil {
		return to.ErrorResult(err)
	}

	client, err := gitea.ClientFromContext(ctx)
	if err != nil {
		return to.ErrorResult(fmt.Errorf("get gitea client err: %v", err))
	}
	_, err = client.ClearIssueLabels(owner, repo, index)
	if err != nil {
		return to.ErrorResult(fmt.Errorf("clear labels on %v/%v/issue/%v err: %v", owner, repo, index, err))
	}
	return to.TextResult("Labels cleared successfully")
}

func removeIssueLabelFn(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallToolResult, error) {
	log.Debugf("Called removeIssueLabelFn")
	owner, err := params.GetString(req.GetArguments(), "owner")
	if err != nil {
		return to.ErrorResult(err)
	}
	repo, err := params.GetString(req.GetArguments(), "repo")
	if err != nil {
		return to.ErrorResult(err)
	}
	index, err := params.GetIndex(req.GetArguments(), "index")
	if err != nil {
		return to.ErrorResult(err)
	}
	labelID, err := params.GetIndex(req.GetArguments(), "label_id")
	if err != nil {
		return to.ErrorResult(err)
	}

	client, err := gitea.ClientFromContext(ctx)
	if err != nil {
		return to.ErrorResult(fmt.Errorf("get gitea client err: %v", err))
	}
	_, err = client.DeleteIssueLabel(owner, repo, index, labelID)
	if err != nil {
		return to.ErrorResult(fmt.Errorf("remove label %v from %v/%v/issue/%v err: %v", labelID, owner, repo, index, err))
	}
	return to.TextResult("Label removed successfully")
}