package tools

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

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

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

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

func (t *RepoMirrorPush) Descriptor() registry.ToolDescriptor {
	return registry.ToolDescriptor{
		Name:        "repo_mirror_push",
		Description: "Manage push mirrors for a repository: add, list, or delete. For the mirror credential, PREFER remote_password_env (the name of an env var the server reads) so the secret never rides the tool-call payload/transcript; remote_password (raw) is discouraged and will be persisted in logs.",
		InputSchema: json.RawMessage(`{
			"type":"object",
			"properties":{
				"owner":{"type":"string"},
				"repo":{"type":"string"},
				"action":{"type":"string","enum":["add","list","delete"]},
				"remote_address":{"type":"string","description":"Mirror target URL (required for add)."},
				"remote_username":{"type":"string"},
				"remote_password_env":{"type":"string","description":"PREFERRED: name of a server-side env var holding the mirror credential; the server resolves it, so the secret is never in this call. Errors if the var is unset."},
				"remote_password":{"type":"string","description":"DISCOURAGED: raw credential — lands in the tool-call transcript/logs. Use remote_password_env instead."},
				"interval":{"type":"string","description":"Sync interval, e.g. '8h0m0s'."},
				"sync_on_commit":{"type":"boolean"},
				"mirror_name":{"type":"string","description":"Remote name to delete (required for delete)."}
			},
			"required":["owner","repo","action"]
		}`),
	}
}

type repoMirrorPushArgs struct {
	Owner             string `json:"owner"`
	Repo              string `json:"repo"`
	Action            string `json:"action"`
	RemoteAddress     string `json:"remote_address"`
	RemoteUsername    string `json:"remote_username"`
	RemotePassword    string `json:"remote_password"`
	RemotePasswordEnv string `json:"remote_password_env"`
	Interval          string `json:"interval"`
	SyncOnCommit      bool   `json:"sync_on_commit"`
	MirrorName        string `json:"mirror_name"`
}

// safeMirror omits remote_password so it is never returned to the caller.
type safeMirror struct {
	ID            int    `json:"id"`
	RemoteName    string `json:"remote_name"`
	RemoteAddress string `json:"remote_address"`
	Interval      string `json:"interval"`
	SyncOnCommit  bool   `json:"sync_on_commit"`
}

func toSafeMirror(m *gitea.PushMirror) safeMirror {
	return safeMirror{
		ID:            m.ID,
		RemoteName:    m.RemoteName,
		RemoteAddress: m.RemoteAddress,
		Interval:      m.Interval,
		SyncOnCommit:  m.SyncOnCommit,
	}
}

// resolveMirrorPassword prefers remote_password_env — the name of a server-side
// env var — so the credential never appears in the tool-call payload (#49). It
// falls back to the raw (discouraged) remote_password. An env name that resolves
// to empty is a loud error, not a silent empty password.
func resolveMirrorPassword(args repoMirrorPushArgs) (string, error) {
	if args.RemotePasswordEnv != "" {
		pw := os.Getenv(args.RemotePasswordEnv)
		if pw == "" {
			return "", fmt.Errorf("remote_password_env %q is unset or empty in the server environment: %w",
				args.RemotePasswordEnv, gitea.ErrValidation)
		}
		return pw, nil
	}
	return args.RemotePassword, nil
}

func (t *RepoMirrorPush) Call(ctx context.Context, raw json.RawMessage) (json.RawMessage, error) {
	var args repoMirrorPushArgs
	if err := parseArgs(raw, &args); err != nil {
		return nil, err
	}
	if err := t.a.Check(ctx, args.Owner); err != nil {
		return nil, err
	}
	switch args.Action {
	case "add":
		password, err := resolveMirrorPassword(args)
		if err != nil {
			return nil, err
		}
		m, err := t.c.AddPushMirror(ctx, args.Owner, args.Repo, gitea.AddPushMirrorArgs{
			RemoteAddress:  args.RemoteAddress,
			RemoteUsername: args.RemoteUsername,
			RemotePassword: password,
			Interval:       args.Interval,
			SyncOnCommit:   args.SyncOnCommit,
		})
		if err != nil {
			return nil, err
		}
		return textOK(toSafeMirror(m))
	case "list":
		mirrors, err := t.c.ListPushMirrors(ctx, args.Owner, args.Repo)
		if err != nil {
			return nil, err
		}
		safe := make([]safeMirror, len(mirrors))
		for i := range mirrors {
			safe[i] = toSafeMirror(&mirrors[i])
		}
		return textOK(safe)
	case "delete":
		if args.MirrorName == "" {
			return nil, fmt.Errorf("mirror_name is required for action=delete")
		}
		if err := t.c.DeletePushMirror(ctx, args.Owner, args.Repo, args.MirrorName); err != nil {
			return nil, err
		}
		return textOK(map[string]string{"status": "deleted", "mirror_name": args.MirrorName})
	default:
		return nil, fmt.Errorf("unknown action %q: must be add, list, or delete", args.Action)
	}
}