package tools

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

	"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 CodeSearch struct {
	c *gitea.Client
	a *allowlist.Allowlist
}

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

func (t *CodeSearch) Descriptor() registry.ToolDescriptor {
	return registry.ToolDescriptor{
		Name:        "code_search",
		Description: "Search code across one repo or fan out across an owner's repos.",
		InputSchema: json.RawMessage(`{
			"type":"object",
			"properties":{
				"q":{"type":"string"},
				"owner":{"type":"string"},
				"repo":{"type":"string"},
				"page":{"type":"integer","minimum":1},
				"limit":{"type":"integer","minimum":1,"maximum":50}
			},
			"required":["q","owner"]
		}`),
	}
}

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

type codeSearchResult struct {
	Repo    string  `json:"repo"`
	Path    string  `json:"path"`
	Snippet string  `json:"snippet"`
	Score   float64 `json:"score"`
	HTMLURL string  `json:"html_url"`
}

func (t *CodeSearch) Call(ctx context.Context, raw json.RawMessage) (json.RawMessage, error) {
	var args codeSearchArgs
	if err := parseArgs(raw, &args); err != nil {
		return nil, err
	}
	if args.Q == "" {
		return nil, fmt.Errorf("q is required: %w", gitea.ErrValidation)
	}
	if err := t.a.Check(args.Owner); err != nil {
		return nil, err
	}
	if args.Page < 1 {
		args.Page = 1
	}
	if args.Limit < 1 || args.Limit > 50 {
		args.Limit = 30
	}

	if args.Repo == "" {
		// Phase 7.2: leave fan-out unimplemented — just error out for now.
		return nil, fmt.Errorf("repo is required for single-repo search (org-wide fan-out lands in 7.3): %w", gitea.ErrValidation)
	}

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

	results := make([]codeSearchResult, 0, len(hits))
	repoFull := args.Owner + "/" + args.Repo
	for _, h := range hits {
		score := h.Score
		if score == 0 {
			score = 1.0
		}
		results = append(results, codeSearchResult{
			Repo:    repoFull,
			Path:    h.Path,
			Snippet: h.Snippet,
			Score:   score,
			HTMLURL: h.HTMLURL,
		})
	}
	out := map[string]any{"results": results}
	if len(hits) == args.Limit {
		out["next_page"] = args.Page + 1
	}
	return textOK(out)
}