package tools

import (
	"context"
	"encoding/json"
	"fmt"
	"strings"

	"gitea.d-ma.be/mathias/gitea-mcp/internal/allowlist"
	"gitea.d-ma.be/mathias/gitea-mcp/internal/gitea"
	"gitea.d-ma.be/mathias/gitea-mcp/internal/registry"
)

type RepoSearch struct {
	c *gitea.Client
	a *allowlist.Allowlist
}

func NewRepoSearch(c *gitea.Client, a *allowlist.Allowlist) *RepoSearch {
	return &RepoSearch{c: c, a: a}
}

func (t *RepoSearch) Descriptor() registry.ToolDescriptor {
	return registry.ToolDescriptor{
		Name:        "repo_search",
		Description: "Search repos by query string. Filters results by owner allowlist.",
		InputSchema: json.RawMessage(`{
			"type":"object",
			"properties":{
				"q":{"type":"string"},
				"owner":{"type":"string"},
				"page":{"type":"integer","minimum":1},
				"limit":{"type":"integer","minimum":1,"maximum":50}
			},
			"required":["q"]
		}`),
	}
}

type repoSearchArgs struct {
	Q     string `json:"q"`
	Owner string `json:"owner"`
	Page  int    `json:"page"`
	Limit int    `json:"limit"`
}

func (t *RepoSearch) Call(ctx context.Context, raw json.RawMessage) (json.RawMessage, error) {
	var args repoSearchArgs
	if err := parseArgs(raw, &args); err != nil {
		return nil, err
	}
	if args.Q == "" {
		return nil, fmt.Errorf("q is required: %w", gitea.ErrValidation)
	}
	if args.Owner != "" {
		if err := t.a.Check(args.Owner); err != nil {
			return nil, err
		}
	}
	if args.Page < 1 {
		args.Page = 1
	}
	args.Limit = capLimit(args.Limit, 30)

	repos, err := t.c.SearchRepos(ctx, args.Q, args.Owner, args.Page, args.Limit)
	if err != nil {
		return nil, err
	}

	// Post-filter when owner not specified — only allowlisted owners survive.
	if args.Owner == "" {
		filtered := make([]gitea.Repo, 0, len(repos))
		for _, r := range repos {
			parts := strings.SplitN(r.FullName, "/", 2)
			if len(parts) != 2 {
				continue
			}
			if t.a.Check(parts[0]) == nil {
				filtered = append(filtered, r)
			}
		}
		repos = filtered
	}

	out := map[string]any{"repos": repos}
	if len(repos) == args.Limit {
		out["next_page"] = args.Page + 1
	}
	return textOK(out)
}