package controllers

import (
	"encoding/json"
	"errors"
	"time"

	"github.com/aoagents/agent-orchestrator/backend/internal/domain"
	projectsvc "github.com/aoagents/agent-orchestrator/backend/internal/service/project"
)

// HTTP response envelopes for the projects surface — the SINGLE definition of
// each wire shape. The handlers encode these (envelope.WriteJSON), and
// apispec.Build reflects these same types into openapi.yaml, so the served
// contract and the generated spec can't disagree. The request side needs no
// wrappers: handlers decode the body straight into the project commands
// (projectsvc.AddInput), which apispec also reflects.

// ProjectIDParam is the {id} path parameter shared by the /projects/{id}
// routes. Handlers read it via chi.URLParam (see projectID); it is declared here
// so every wire input/output shape has one home, and apispec.Build reflects it
// as the path parameter.
type ProjectIDParam struct {
	ID string `path:"id" description:"Project identifier (registry key)."`
}

// ListProjectsResponse is the body of GET /api/v1/projects.
type ListProjectsResponse struct {
	Projects []projectsvc.Summary `json:"projects"`
}

// ProjectResponse is the { project } body shared by POST /projects (201).
type ProjectResponse struct {
	Project projectsvc.Project `json:"project"`
}

// GetProjectResponse is the { status, project } body of GET /projects/{id},
// where project is oneOf Project|Degraded discriminated by status.
type GetProjectResponse struct {
	Status  string            `json:"status" enum:"ok,degraded"`
	Project ProjectOrDegraded `json:"project"`
}

// ProjectOrDegraded is the discriminated `project` field: exactly one of
// Project/Degraded is set. It marshals as whichever is present (so the handler
// emits the right object) and exposes the oneOf variants to the spec reflector
// (so apispec.Build emits `oneOf: [Project, Degraded]`) — one type, both jobs.
type ProjectOrDegraded struct {
	Project  *projectsvc.Project
	Degraded *projectsvc.Degraded
}

// MarshalJSON encodes whichever variant is set (Project or Degraded).
func (p ProjectOrDegraded) MarshalJSON() ([]byte, error) {
	switch {
	case p.Degraded != nil:
		return json.Marshal(p.Degraded)
	case p.Project != nil:
		return json.Marshal(p.Project)
	default:
		// Unreachable in practice: the handler validates the GetResult via
		// newGetProjectResponse and writes a 500 before committing the 200
		// status, so this never encodes. Kept as a last-resort backstop —
		// erroring is still better than emitting a contract-breaking `null`,
		// though by here the status is already sent, so the real guard is
		// upstream.
		return nil, errEmptyProjectOrDegraded
	}
}

// errEmptyProjectOrDegraded marks a GetResult that set neither variant — a
// Manager-contract violation. newGetProjectResponse returns it so the handler
// can map it to a 500 before any response bytes are written.
var errEmptyProjectOrDegraded = errors.New("controllers: GetResult has neither Project nor Degraded set")

// JSONSchemaOneOf is read by swaggest's reflector (apispec.Build) to emit the
// oneOf for this field; it is not used at runtime.
func (ProjectOrDegraded) JSONSchemaOneOf() []interface{} {
	return []interface{}{projectsvc.Project{}, projectsvc.Degraded{}}
}

// newGetProjectResponse maps the internal GetResult onto the wire envelope —
// the explicit project→httpd boundary the result type exists for. It errors
// when the result sets neither variant, so the handler can return a clean 500
// BEFORE writing the 200 status rather than flushing a truncated body.
func newGetProjectResponse(res projectsvc.GetResult) (GetProjectResponse, error) {
	if res.Project == nil && res.Degraded == nil {
		return GetProjectResponse{}, errEmptyProjectOrDegraded
	}
	return GetProjectResponse{
		Status:  res.Status,
		Project: ProjectOrDegraded{Project: res.Project, Degraded: res.Degraded},
	}, nil
}

// SessionIDParam is the {sessionId} path parameter shared by session routes.
type SessionIDParam struct {
	SessionID string `path:"sessionId" description:"Session identifier, e.g. project-1."`
}

// ListSessionsQuery is the query string accepted by GET /api/v1/sessions.
type ListSessionsQuery struct {
	Project          string `query:"project,omitempty" description:"Project id filter."`
	Active           *bool  `query:"active,omitempty" description:"When true, return non-terminated sessions; when false, return terminated sessions."`
	OrchestratorOnly *bool  `query:"orchestratorOnly,omitempty" description:"When true, return only orchestrator sessions."`
	Fresh            *bool  `query:"fresh,omitempty" description:"When true, return only fresh non-terminated sessions."`
}

// CleanupSessionsQuery is the query string accepted by POST /api/v1/sessions/cleanup.
type CleanupSessionsQuery struct {
	Project string `query:"project,omitempty" description:"Project id filter. When omitted, clean terminated sessions across all projects."`
}

// ListSessionsResponse is the body of GET /api/v1/sessions.
type ListSessionsResponse struct {
	Sessions []domain.Session `json:"sessions"`
}

// SpawnSessionRequest is the body of POST /api/v1/sessions.
type SpawnSessionRequest struct {
	ProjectID  domain.ProjectID    `json:"projectId"`
	IssueID    domain.IssueID      `json:"issueId,omitempty"`
	Kind       domain.SessionKind  `json:"kind,omitempty" enum:"worker,orchestrator"`
	Harness    domain.AgentHarness `json:"harness,omitempty" enum:"claude-code,codex,aider,opencode,grok,droid,amp,agy,crush,cursor,qwen,copilot,goose,auggie,continue,devin,cline,kimi,kiro,kilocode,vibe,pi,autohand"`
	Branch     string              `json:"branch,omitempty"`
	Prompt     string              `json:"prompt,omitempty" maxLength:"4096"`
	AgentRules string              `json:"agentRules,omitempty"`
}

// SessionResponse is the { session } body shared by session create/get.
type SessionResponse struct {
	Session domain.Session `json:"session"`
}

// RenameSessionRequest is the body of PATCH /api/v1/sessions/{sessionId}.
type RenameSessionRequest struct {
	DisplayName string `json:"displayName" minLength:"1"`
}

// RenameSessionResponse is the body of PATCH /api/v1/sessions/{sessionId}.
type RenameSessionResponse struct {
	OK          bool             `json:"ok"`
	SessionID   domain.SessionID `json:"sessionId"`
	DisplayName string           `json:"displayName"`
}

// RestoreSessionResponse is the body of POST /api/v1/sessions/{sessionId}/restore.
type RestoreSessionResponse struct {
	OK        bool             `json:"ok"`
	SessionID domain.SessionID `json:"sessionId"`
	Session   domain.Session   `json:"session"`
}

// KillSessionResponse is the body of POST /api/v1/sessions/{sessionId}/kill.
type KillSessionResponse struct {
	OK        bool             `json:"ok"`
	SessionID domain.SessionID `json:"sessionId"`
	Freed     bool             `json:"freed,omitempty"`
}

// CleanupSessionsResponse is the body of POST /api/v1/sessions/cleanup.
type CleanupSessionsResponse struct {
	OK      bool               `json:"ok"`
	Cleaned []domain.SessionID `json:"cleaned"`
}

// SendSessionMessageRequest is the body of POST /api/v1/sessions/{sessionId}/send.
type SendSessionMessageRequest struct {
	Message string `json:"message" minLength:"1" maxLength:"4096"`
}

// SendSessionMessageResponse is the body of POST /api/v1/sessions/{sessionId}/send.
type SendSessionMessageResponse struct {
	OK        bool             `json:"ok"`
	SessionID domain.SessionID `json:"sessionId"`
	Message   string           `json:"message"`
}

// SessionPRFacts is the pull-request read shape returned under session PR routes.
type SessionPRFacts struct {
	URL            string                `json:"url"`
	Number         int                   `json:"number"`
	State          string                `json:"state" enum:"draft,open,merged,closed"`
	CI             domain.CIState        `json:"ci"`
	Review         domain.ReviewDecision `json:"review"`
	Mergeability   domain.Mergeability   `json:"mergeability"`
	ReviewComments bool                  `json:"reviewComments"`
	UpdatedAt      time.Time             `json:"updatedAt"`
}

// ListSessionPRsResponse is the body of GET /sessions/{sessionId}/pr.
type ListSessionPRsResponse struct {
	SessionID domain.SessionID `json:"sessionId"`
	PRs       []SessionPRFacts `json:"prs"`
}

// ClaimPRRequest is the body of POST /sessions/{sessionId}/pr/claim.
type ClaimPRRequest struct {
	PR            string `json:"pr" minLength:"1"`
	AllowTakeover *bool  `json:"allowTakeover,omitempty"`
}

// ClaimPRResponse is the body of POST /sessions/{sessionId}/pr/claim.
type ClaimPRResponse struct {
	OK            bool               `json:"ok"`
	SessionID     domain.SessionID   `json:"sessionId"`
	PRs           []SessionPRFacts   `json:"prs"`
	BranchChanged bool               `json:"branchChanged"`
	TakenOverFrom []domain.SessionID `json:"takenOverFrom"`
}

// SetActivityRequest is the body of POST /api/v1/sessions/{sessionId}/activity.
type SetActivityRequest struct {
	State string `json:"state" enum:"active,idle,waiting_input,exited" description:"Agent activity state reported by an agent hook."`
}

// SetActivityResponse is the body of POST /api/v1/sessions/{sessionId}/activity.
type SetActivityResponse struct {
	OK        bool             `json:"ok"`
	SessionID domain.SessionID `json:"sessionId"`
	State     string           `json:"state"`
}

// OrchestratorIDParam is the {id} path parameter for orchestrator routes.
type OrchestratorIDParam struct {
	ID string `path:"id" description:"Orchestrator session identifier, e.g. project-orchestrator."`
}

// SpawnOrchestratorRequest is the body of POST /api/v1/orchestrators.
type SpawnOrchestratorRequest struct {
	ProjectID domain.ProjectID `json:"projectId"`
	Clean     bool             `json:"clean,omitempty"`
}

// SpawnOrchestratorResponse is the body of POST /api/v1/orchestrators.
type SpawnOrchestratorResponse struct {
	Orchestrator OrchestratorResponse `json:"orchestrator"`
}

// OrchestratorResponse is the minimal orchestrator read model returned after spawn.
type OrchestratorResponse struct {
	ID          domain.SessionID `json:"id"`
	ProjectID   domain.ProjectID `json:"projectId"`
	ProjectName string           `json:"projectName,omitempty"`
}

// PRIDParam is the {id} path parameter shared by the /prs/{id} routes.
type PRIDParam struct {
	ID string `path:"id" description:"PR number."`
}

// MergePRResponse is the body of POST /api/v1/prs/{id}/merge (200).
type MergePRResponse struct {
	OK       bool   `json:"ok"`
	PRNumber int    `json:"prNumber"`
	Method   string `json:"method"`
}

// ResolveCommentsRequest is the optional body of POST /api/v1/prs/{id}/resolve-comments.
type ResolveCommentsRequest struct {
	CommentIDs []string `json:"commentIds,omitempty"`
}

// ResolveCommentsResponse is the body of POST /api/v1/prs/{id}/resolve-comments (200).
type ResolveCommentsResponse struct {
	OK       bool `json:"ok"`
	Resolved int  `json:"resolved"`
}